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fix procfs changes and something other minor things.

Peng Tao and others added 4 commits May 22, 2013 21:01
We missed one file...

Signed-off-by: Peng Tao <tao.peng@emc.com>
In 3.10 merge window, proc_dir_entry is now private to proc. However,
Lustre lprocfs depends heavily on it and its now-gone read_proc_t and
write_proc_t members.

The patch largely changed the fact, and made lprocfs depend on none of
proc_dir_entry private members. All lprocfs callers are converted to
use the new seq_file scheme.

Also lprocfs_srch is removed so that we can drop lprocfs_lock. All callers
are changed to save created pde in proper place.

See https://jira.hpdd.intel.com/browse/LU-3319 for more details.

Signed-off-by: Peng Tao <tao.peng@emc.com>
ldlm_proc_setup and ldlm_proc_cleanup should reset global
pde pointers otherwise remount may hit
LASSERT(ldlm_ns_proc_dir == NULL);

Also in libcfs_sock_ioctl, fput() includes itself sock_release.
So don't call sock_release twice otherwise kernel may oops
due to incorrect inode ref counting.

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
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Siyao, I've send a new version at #2. Please see if it looks good when you have time. Thank you very much!

bergwolf pushed a commit that referenced this pull request May 27, 2013
This can easily be triggered if a new CPU is added (via
ACPI hotplug mechanism) and from user-space you do:

   echo 1 > /sys/devices/system/cpu/cpu3/online

(or wait for UDEV to do it) on a newly appeared physical CPU.

The deadlock is that the "store_online" in drivers/base/cpu.c
takes the cpu_hotplug_driver_lock() lock, then calls "cpu_up".
"cpu_up" eventually ends up calling "save_mc_for_early"
which also takes the cpu_hotplug_driver_lock() lock.

And here is that lockdep thinks of it:

 smpboot: Stack at about ffff880075c39f44
 smpboot: CPU3: has booted.
 microcode: CPU3 sig=0x206a7, pf=0x2, revision=0x25

 =============================================
 [ INFO: possible recursive locking detected ]
 3.9.0upstream-10129-g167af0e #1 Not tainted
 ---------------------------------------------
 sh/2487 is trying to acquire lock:
  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81075512>] cpu_hotplug_driver_lock+0x12/0x20

 but task is already holding lock:
  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81075512>] cpu_hotplug_driver_lock+0x12/0x20

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(x86_cpu_hotplug_driver_mutex);
   lock(x86_cpu_hotplug_driver_mutex);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by sh/2487:
  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff811ca48d>] vfs_write+0x17d/0x190
  #1:  (&buffer->mutex){+.+.+.}, at: [<ffffffff812464ef>] sysfs_write_file+0x3f/0x160
  #2:  (s_active#20){.+.+.+}, at: [<ffffffff81246578>] sysfs_write_file+0xc8/0x160
  #3:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81075512>] cpu_hotplug_driver_lock+0x12/0x20
  #4:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff810961c2>] cpu_maps_update_begin+0x12/0x20
  #5:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810962a7>] cpu_hotplug_begin+0x27/0x60

Suggested-and-Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: fenghua.yu@intel.com
Cc: xen-devel@lists.xensource.com
Cc: stable@vger.kernel.org # for v3.9
Link: http://lkml.kernel.org/r/1368029583-23337-1-git-send-email-konrad.wilk@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
bergwolf pushed a commit that referenced this pull request May 27, 2013
… into node number

df2d5ae ("workqueue: map an unbound workqueues to multiple per-node
pool_workqueues") made unbound workqueues to map to multiple per-node
pool_workqueues and accordingly updated workqueue_contested() so that,
for unbound workqueues, it maps the specified @cpu to the NUMA node
number to obtain the matching pool_workqueue to query the congested
state.

Before this change, workqueue_congested() ignored @cpu for unbound
workqueues as there was only one pool_workqueue and some users
(fscache) called it with WORK_CPU_UNBOUND.  After the commit, this
causes the following oops as WORK_CPU_UNBOUND gets translated to
garbage by cpu_to_node().

  BUG: unable to handle kernel paging request at ffff8803598d98b8
  IP: [<ffffffff81043b7e>] unbound_pwq_by_node+0xa1/0xfa
  PGD 2421067 PUD 0
  Oops: 0000 [#1] SMP
  CPU: 1 PID: 2689 Comm: cat Tainted: GF            3.9.0-fsdevel+ #4
  task: ffff88003d801040 ti: ffff880025806000 task.ti: ffff880025806000
  RIP: 0010:[<ffffffff81043b7e>]  [<ffffffff81043b7e>] unbound_pwq_by_node+0xa1/0xfa
  RSP: 0018:ffff880025807ad8  EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff8800388a2400 RCX: 0000000000000003
  RDX: ffff880025807fd8 RSI: ffffffff81a31420 RDI: ffff88003d8016e0
  RBP: ffff880025807ae8 R08: ffff88003d801730 R09: ffffffffa00b4898
  R10: ffffffff81044217 R11: ffff88003d801040 R12: 0000000064206e97
  R13: ffff880036059d98 R14: ffff880038cc8080 R15: ffff880038cc82d0
  FS:  00007f21afd9c740(0000) GS:ffff88003d100000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: ffff8803598d98b8 CR3: 000000003df49000 CR4: 00000000000007e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Stack:
   ffff8800388a2400 0000000000000002 ffff880025807b18 ffffffff810442ce
   ffffffff81044217 ffff880000000002 ffff8800371b4080 ffff88003d112ec0
   ffff880025807b38 ffffffffa00810b0 ffff880036059d88 ffff880036059be8
  Call Trace:
   [<ffffffff810442ce>] workqueue_congested+0xb7/0x12c
   [<ffffffffa00810b0>] fscache_enqueue_object+0xb2/0xe8 [fscache]
   [<ffffffffa007facd>] __fscache_acquire_cookie+0x3b9/0x56c [fscache]
   [<ffffffffa00ad8fe>] nfs_fscache_set_inode_cookie+0xee/0x132 [nfs]
   [<ffffffffa009e112>] do_open+0x9/0xd [nfs]
   [<ffffffff810e804a>] do_dentry_open+0x175/0x24b
   [<ffffffff810e8298>] finish_open+0x41/0x51

Fix it by using smp_processor_id() if @cpu is WORK_CPU_UNBOUND.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: David Howells <dhowells@redhat.com>
Tested-and-Acked-by: David Howells <dhowells@redhat.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
ibm,validate-flash-image RTAS call output buffer contains 150 - 200
bytes of data on latest system. Presently we have output
buffer size as 64 bytes and we use sprintf to copy data from
RTAS buffer to local buffer. This causes kernel oops (see below
call trace).

This patch increases local buffer size to 256 and also uses
snprintf instead of sprintf to copy data from RTAS buffer.

Kernel call trace :
-------------------
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=1024 NUMA pSeries
Modules linked in: nfs fscache lockd auth_rpcgss nfs_acl sunrpc fuse loop dm_mod ipv6 ipv6_lib usb_storage ehea(X) sr_mod qlge ses cdrom enclosure st be2net sg ext3 jbd mbcache usbhid hid ohci_hcd ehci_hcd usbcore qla2xxx usb_common sd_mod crc_t10dif scsi_dh_hp_sw scsi_dh_rdac scsi_dh_alua scsi_dh_emc scsi_dh lpfc scsi_transport_fc scsi_tgt ipr(X) libata scsi_mod
Supported: Yes
NIP: 4520323031333130 LR: 4520323031333130 CTR: 0000000000000000
REGS: c0000001b91779b0 TRAP: 0400   Tainted: G            X  (3.0.13-0.27-ppc64)
MSR: 8000000040009032 <EE,ME,IR,DR>  CR: 44022488  XER: 20000018
TASK = c0000001bca1aba0[4736] 'cat' THREAD: c0000001b9174000 CPU: 36
GPR00: 4520323031333130 c0000001b9177c30 c000000000f87c98 000000000000009b
GPR04: c0000001b9177c4a 000000000000000b 3520323031333130 2032303133313031
GPR08: 3133313031350a4d 000000000000009b 0000000000000000 c0000000003664a4
GPR12: 0000000022022448 c000000003ee6c00 0000000000000002 00000000100e8a90
GPR16: 00000000100cb9d8 0000000010093370 000000001001d310 0000000000000000
GPR20: 0000000000008000 00000000100fae60 000000000000005e 0000000000000000
GPR24: 0000000010129350 46573738302e3030 2046573738302e30 300a4d4720323031
GPR28: 333130313520554e 4b4e4f574e0a4d47 2032303133313031 3520323031333130
NIP [4520323031333130] 0x4520323031333130
LR [4520323031333130] 0x4520323031333130
Call Trace:
[c0000001b9177c30] [4520323031333130] 0x4520323031333130 (unreliable)
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
bergwolf pushed a commit that referenced this pull request May 27, 2013
Tony Jones reported that the ftrace self tests on s390 do not work:

<6>Testing dynamic ftrace ops #1: (0 0 0 0 0) FAILED!
<6>Testing tracer irqsoff:
<3>failed to start irqsoff tracer
<4>.. no entries found ..FAILED!
<6>Testing tracer wakeup:
<3>failed to start wakeup tracer
<4>.. no entries found ..FAILED!
<6>Testing tracer function_graph:
<4>Failed to init function_graph tracer, init returned -19
<4>FAILED!

This happens because we forgot to adjust the instruction pointer that gets
passed to the ftrace trace function by MCOUNT_INSN_SIZE.

In addition change MCOUNT_INSN_SIZE to the correct value on 31 bit.
It only worked so far because the to be patched instruction was identical.

Reported-by: Tony Jones <tonyj@suse.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
…q_numa_init()

wq_numa_init() builds per-node cpumasks which are later used to make
unbound workqueues NUMA-aware.  The cpumasks are allocated using
alloc_cpumask_var_node() for all possible nodes.  Unfortunately, on
machines with off-line nodes, this leads to NUMA-aware allocations on
existing bug offline nodes, which in turn triggers BUG in the memory
allocation code.

Fix it by using NUMA_NO_NODE for cpumask allocations for offline
nodes.

  kernel BUG at include/linux/gfp.h:323!
  invalid opcode: 0000 [#1] SMP
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0+ #1
  Hardware name: ProLiant BL465c G7, BIOS A19 12/10/2011
  task: ffff880234608000 ti: ffff880234602000 task.ti: ffff880234602000
  RIP: 0010:[<ffffffff8117495d>]  [<ffffffff8117495d>] new_slab+0x2ad/0x340
  RSP: 0000:ffff880234603bf8  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff880237404b40 RCX: 00000000000000d0
  RDX: 0000000000000001 RSI: 0000000000000003 RDI: 00000000002052d0
  RBP: ffff880234603c28 R08: 0000000000000000 R09: 0000000000000001
  R10: 0000000000000001 R11: ffffffff812e3aa8 R12: 0000000000000001
  R13: ffff8802378161c0 R14: 0000000000030027 R15: 00000000000040d0
  FS:  0000000000000000(0000) GS:ffff880237800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: ffff88043fdff000 CR3: 00000000018d5000 CR4: 00000000000007f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Stack:
   ffff880234603c28 0000000000000001 00000000000000d0 ffff8802378161c0
   ffff880237404b40 ffff880237404b40 ffff880234603d28 ffffffff815edba1
   ffff880237816140 0000000000000000 ffff88023740e1c0
  Call Trace:
   [<ffffffff815edba1>] __slab_alloc+0x330/0x4f2
   [<ffffffff81174b25>] kmem_cache_alloc_node_trace+0xa5/0x200
   [<ffffffff812e3aa8>] alloc_cpumask_var_node+0x28/0x90
   [<ffffffff81a0bdb3>] wq_numa_init+0x10d/0x1be
   [<ffffffff81a0bec8>] init_workqueues+0x64/0x341
   [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
   [<ffffffff819f1f31>] kernel_init_freeable+0xb7/0x1ec
   [<ffffffff815d50de>] kernel_init+0xe/0xf0
   [<ffffffff815ff89c>] ret_from_fork+0x7c/0xb0
  Code: 45  84 ac 00 00 00 f0 41 80 4d 00 40 e9 f6 fe ff ff 66 0f 1f 84 00 00 00 00 00 e8 eb 4b ff ff 49 89 c5 e9 05 fe ff ff <0f> 0b 4c 8b 73 38 44 89 ff 81 cf 00 00 20 00 4c 89 f6 48 c1 ee

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-Tested-by: Lingzhu Xiang <lxiang@redhat.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
It is required to enable respective clock-domain before
enabling any clock/module inside that clock-domain.

During common-clock migration, .clkdm_name field got missed
for "clkdiv32k_ick" clock, which leaves "clk_24mhz_clkdm"
unused; so it will be disabled even if childs of this clock-domain
is enabled, which keeps child modules in idle mode.

This fixes the kernel crash observed on AM335xEVM-SK platform,
where clkdiv32_ick clock is being used as a gpio debounce clock
and since clkdiv32k_ick is in idle mode it leads to below crash -

Crash Log:
==========
[    2.598347] Unhandled fault: external abort on non-linefetch (0x1028) at
0xfa1ac150
[    2.606434] Internal error: : 1028 [#1] SMP ARM
[    2.611207] Modules linked in:
[    2.614449] CPU: 0    Not tainted  (3.8.4-01382-g1f449cd-dirty #4)
[    2.620973] PC is at _set_gpio_debounce+0x60/0x104
[    2.626025] LR is at clk_enable+0x30/0x3c

Cc: stable@vger.kernel.org # v3.9
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
Make sure that any open relayfs files are closed before
unregistering with mac80211, otherwise this crash is seen:

[ 1331.097846] BUG: unable to handle kernel paging request at 6b6b6b8b
[ 1331.098170] IP: [<c063d0d6>] debugfs_remove+0x26/0x80
[ 1331.098170] *pdpt = 000000002f9aa001 *pde = 0000000000000000
[ 1331.098170] Oops: 0000 [#1] PREEMPT SMP
[ 1331.098170] Modules linked in: iptable_raw xt_CT nf_conntrack_ipv4 nf_defrag]
[ 1331.098170] Pid: 4794, comm: rmmod Tainted: G        WC   3.9.1+ #5 To Be Fi.
[ 1331.098170] EIP: 0060:[<c063d0d6>] EFLAGS: 00010202 CPU: 0
[ 1331.098170] EIP is at debugfs_remove+0x26/0x80
[ 1331.098170] EAX: f2f3acd0 EBX: f2f3acd0 ECX: 00000006 EDX: f8622348
[ 1331.098170] ESI: 6b6b6b6b EDI: 00000001 EBP: ee251e1 ESP: ee251e0c
[ 1331.098170]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1331.098170] CR0: 8005003b CR2: 6b6b6b8b CR3: 2e7b7000 CR4: 000007e0
[ 1331.098170] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 1331.098170] DR6: ffff0ff0 DR7: 00000400
[ 1331.098170] Process rmmod (pid: 4794, ti=ee250000 task=efaa2560 task.ti=ee25)
[ 1331.098170] Stack:
[ 1331.098170]  f241e170 0000000a ee251e1c f861394d ee251e28 c04e3088 f241e170 4
[ 1331.098170]  c04e30f f45482b0 ee251e54 c04e3187 f25e86b0 ee251e54 f8618748 0
[ 1331.098170]  0000000a 00000001 ee251e68 f860065b f2509e20 f25085a0 f5b6e8a4 8
[ 1331.098170] Call Trace:
[ 1331.098170]  [<f861394d>] remove_buf_file_handler+0xd/0x20 [ath9k]
[ 1331.098170]  [<c04e3088>] relay_remove_buf+0x18/0x30
[ 1331.098170]  [<c04e30fe>] relay_close_buf+0x2e/0x40
[ 1331.098170]  [<c04e3187>] relay_close+0x77/0xf0
[ 1331.098170]  [<f8618748>] ? dpd_exit+0x38/0x40 [ath9k]
[ 1331.098170]  [<f860065b>] ath9k_deinit_softc+0x8b/0xa0 [ath9k]
[ 1331.098170]  [<f86006b8>] ath9k_deinit_device+0x48/0x60 [ath9k]
[ 1331.098170]  [<f86107f1>] ath_pci_remove+0x31/0x50 [ath9k]
[ 1331.098170]  [<c06dbff8>] pci_device_remove+0x38/0xc0
[ 1331.098170]  [<c079daa4>] __device_release_driver+0x64/0xc0
[ 1331.098170]  [<c079db97>] driver_detach+0x97/0xa0
[ 1331.098170]  [<c079cacc>] bus_remove_driver+0x6c/0xe0
[ 1331.098170]  [<c079c197>] ? bus_put+0x17/0x20
[ 1331.098170]  [<c079cae3>] ? bus_remove_driver+0x83/0xe0
[ 1331.098170]  [<c079e709>] driver_unregister+0x49/0x80
[ 1331.098170]  [<c06dc138>] pci_unregister_driver+0x18/0x80
[ 1331.098170]  [<f8610602>] ath_pci_exit+0x12/0x20 [ath9k]
[ 1331.098170]  [<f8619ce0>] ath9k_exit+0x17/0x337 [ath9k]
[ 1331.098170]  [<c09e537d>] ? mutex_unlock+0xd/0x10
[ 1331.098170]  [<c04bd36c>] sys_delete_module+0x17c/0x250
[ 1331.098170]  [<c0540dc4>] ? do_munmap+0x244/0x2d0
[ 1331.098170]  [<c0540e96>] ? vm_munmap+0x46/0x60
[ 1331.098170]  [<c09e8dc4>] ? restore_all+0xf/0xf
[ 1331.098170]  [<c09ebf50>] ? __do_page_fault+0x4c0/0x4c0
[ 1331.098170]  [<c04b18e4>] ? trace_hardirqs_on_caller+0xf4/0x180
[ 1331.098170]  [<c09ef28d>] sysenter_do_call+0x12/0x38
[ 1331.098170] Code: 90 8d 74 26 00 55 89 e5 83 ec 08 89 1c 24 89 74 24 04 3e 82
[ 1331.098170] EIP: [<c063d0d6>] debugfs_remove+0x26/0x80 SS:ESP 0068:ee251e0c
[ 1331.098170] CR2: 000000006b6b6b8b
[ 1331.727971] ---[ end trace b5bb9f2066cef7f9 ]---

Cc: <stable@vger.kernel.org>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
i2c: suppress lockdep warning on delete_device

Since commit 846f997 the following lockdep
warning is thrown in case i2c device is removed (via delete_device sysfs
attribute) which contains subdevices (e.g. i2c multiplexer):

=============================================
[ INFO: possible recursive locking detected ]
3.8.7-0-sampleversion-fct #8 Tainted: G           O
---------------------------------------------
bash/3743 is trying to acquire lock:
  (s_active#110){++++.+}, at: [<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8

but task is already holding lock:
  (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(s_active#110);
   lock(s_active#110);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

4 locks held by bash/3743:
  #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff802b3c3c>] sysfs_write_file+0x4c/0x208
  #1:  (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208
  #2:  (&adap->userspace_clients_lock/1){+.+.+.}, at: [<ffffffff80454a18>] i2c_sysfs_delete_device+0x90/0x238
  #3:  (&__lockdep_no_validate__){......}, at: [<ffffffff803dcc24>] device_release_driver+0x24/0x48

stack backtrace:
Call Trace:
[<ffffffff80575cc8>] dump_stack+0x8/0x34
[<ffffffff801b50fc>] __lock_acquire+0x161c/0x2110
[<ffffffff801b5c3c>] lock_acquire+0x4c/0x70
[<ffffffff802b60cc>] sysfs_addrm_finish+0x19c/0x1e0
[<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8
[<ffffffff802b7d8c>] sysfs_remove_group+0x64/0x148
[<ffffffff803d990c>] device_remove_attrs+0x9c/0x1a8
[<ffffffff803d9b1c>] device_del+0x104/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff8045505c>] i2c_del_adapter+0x1cc/0x328
[<ffffffff8045802c>] i2c_del_mux_adapter+0x14/0x38
[<ffffffffc025c108>] pca954x_remove+0x90/0xe0 [pca954x]
[<ffffffff804542f8>] i2c_device_remove+0x80/0xe8
[<ffffffff803dca9c>] __device_release_driver+0x74/0xf8
[<ffffffff803dcc2c>] device_release_driver+0x2c/0x48
[<ffffffff803dbc14>] bus_remove_device+0x13c/0x1d8
[<ffffffff803d9b24>] device_del+0x10c/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff80454b08>] i2c_sysfs_delete_device+0x180/0x238
[<ffffffff802b3cd4>] sysfs_write_file+0xe4/0x208
[<ffffffff8023ddc4>] vfs_write+0xbc/0x160
[<ffffffff8023df6c>] SyS_write+0x54/0xd8
[<ffffffff8013d424>] handle_sys64+0x44/0x64

The problem is already known for USB and PCI subsystems. The reason is that
delete_device attribute is defined statically in i2c-core.c and used for all
devices in i2c subsystem.

Discussion of original USB problem:
http://lkml.indiana.edu/hypermail/linux/kernel/1204.3/01160.html

Commit 356c05d introduced new macro to suppress
lockdep warnings for this special case and included workaround for USB code.

LKML discussion of the workaround:
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/03634.html

As i2c case is in principle the same, the same workaround could be used here.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
bergwolf pushed a commit that referenced this pull request May 27, 2013
Now that the tty port owns the flip buffers and i/o is allowed
from the driver even when no tty is attached, the destruction
of the tty port (and the flip buffers) must ensure that no
outstanding work is pending.

Unfortunately, this creates a lock order problem with the
console_lock (see attached lockdep report [1] below).

For single console deallocation, drop the console_lock prior
to port destruction. When multiple console deallocation,
defer port destruction until the consoles have been
deallocated.

tty_port_destroy() is not required if the port has not
been used; remove from vc_allocate() failure path.

[1] lockdep report from Dave Jones <davej@redhat.com>

 ======================================================
 [ INFO: possible circular locking dependency detected ]
 3.9.0+ #16 Not tainted
 -------------------------------------------------------
 (agetty)/26163 is trying to acquire lock:
 blocked:  ((&buf->work)){+.+...}, instance: ffff88011c8b0020, at: [<ffffffff81062065>] flush_work+0x5/0x2e0

 but task is already holding lock:
 blocked:  (console_lock){+.+.+.}, instance: ffffffff81c2fde0, at: [<ffffffff813bc201>] vt_ioctl+0xb61/0x1230

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (console_lock){+.+.+.}:
        [<ffffffff810b3f74>] lock_acquire+0xa4/0x210
        [<ffffffff810416c7>] console_lock+0x77/0x80
        [<ffffffff813c3dcd>] con_flush_chars+0x2d/0x50
        [<ffffffff813b32b2>] n_tty_receive_buf+0x122/0x14d0
        [<ffffffff813b7709>] flush_to_ldisc+0x119/0x170
        [<ffffffff81064381>] process_one_work+0x211/0x700
        [<ffffffff8106498b>] worker_thread+0x11b/0x3a0
        [<ffffffff8106ce5d>] kthread+0xed/0x100
        [<ffffffff81601cac>] ret_from_fork+0x7c/0xb0

 -> #0 ((&buf->work)){+.+...}:
        [<ffffffff810b349a>] __lock_acquire+0x193a/0x1c00
        [<ffffffff810b3f74>] lock_acquire+0xa4/0x210
        [<ffffffff810620ae>] flush_work+0x4e/0x2e0
        [<ffffffff81065305>] __cancel_work_timer+0x95/0x130
        [<ffffffff810653b0>] cancel_work_sync+0x10/0x20
        [<ffffffff813b8212>] tty_port_destroy+0x12/0x20
        [<ffffffff813c65e8>] vc_deallocate+0xf8/0x110
        [<ffffffff813bc20c>] vt_ioctl+0xb6c/0x1230
        [<ffffffff813b01a5>] tty_ioctl+0x285/0xd50
        [<ffffffff811ba825>] do_vfs_ioctl+0x305/0x530
        [<ffffffff811baad1>] sys_ioctl+0x81/0xa0
        [<ffffffff81601d59>] system_call_fastpath+0x16/0x1b

 other info that might help us debug this:

 [ 6760.076175]  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(console_lock);
                                lock((&buf->work));
                                lock(console_lock);
   lock((&buf->work));

  *** DEADLOCK ***

 1 lock on stack by (agetty)/26163:
  #0: blocked:  (console_lock){+.+.+.}, instance: ffffffff81c2fde0, at: [<ffffffff813bc201>] vt_ioctl+0xb61/0x1230
 stack backtrace:
 Pid: 26163, comm: (agetty) Not tainted 3.9.0+ #16
 Call Trace:
  [<ffffffff815edb14>] print_circular_bug+0x200/0x20e
  [<ffffffff810b349a>] __lock_acquire+0x193a/0x1c00
  [<ffffffff8100a269>] ? sched_clock+0x9/0x10
  [<ffffffff8100a269>] ? sched_clock+0x9/0x10
  [<ffffffff8100a200>] ? native_sched_clock+0x20/0x80
  [<ffffffff810b3f74>] lock_acquire+0xa4/0x210
  [<ffffffff81062065>] ? flush_work+0x5/0x2e0
  [<ffffffff810620ae>] flush_work+0x4e/0x2e0
  [<ffffffff81062065>] ? flush_work+0x5/0x2e0
  [<ffffffff810b15db>] ? mark_held_locks+0xbb/0x140
  [<ffffffff8113c8a3>] ? __free_pages_ok.part.57+0x93/0xc0
  [<ffffffff810b15db>] ? mark_held_locks+0xbb/0x140
  [<ffffffff810652f2>] ? __cancel_work_timer+0x82/0x130
  [<ffffffff81065305>] __cancel_work_timer+0x95/0x130
  [<ffffffff810653b0>] cancel_work_sync+0x10/0x20
  [<ffffffff813b8212>] tty_port_destroy+0x12/0x20
  [<ffffffff813c65e8>] vc_deallocate+0xf8/0x110
  [<ffffffff813bc20c>] vt_ioctl+0xb6c/0x1230
  [<ffffffff810aec41>] ? lock_release_holdtime.part.30+0xa1/0x170
  [<ffffffff813b01a5>] tty_ioctl+0x285/0xd50
  [<ffffffff812b00f6>] ? inode_has_perm.isra.46.constprop.61+0x56/0x80
  [<ffffffff811ba825>] do_vfs_ioctl+0x305/0x530
  [<ffffffff812b04db>] ? selinux_file_ioctl+0x5b/0x110
  [<ffffffff811baad1>] sys_ioctl+0x81/0xa0
  [<ffffffff81601d59>] system_call_fastpath+0x16/0x1b

Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bergwolf pushed a commit that referenced this pull request May 27, 2013
This reverts commit a99d76f (leds: leds-gpio: use gpio_request_one)
and commit 2d7c22f (leds: leds-gpio: set devm_gpio_request_one()
flags param correctly) which was a fix of the first one.

The conversion to devm_gpio_request in commit e3b1d44 (leds:
leds-gpio: use devm_gpio_request_one) is not reverted.

The problem is that gpio_cansleep() and gpio_get_value_cansleep()
calls can crash if the gpio is not first reserved. Incidentally this
same bug existed earlier and was fixed similarly in commit d95cbe6
(leds: Fix potential leds-gpio oops). But the OOPS is real. It happens
when GPIOs are provided by module which is not yet loaded.

So this fixes the following BUG during my ALIX boot (3.9.2-vanilla):

BUG: unable to handle kernel NULL pointer dereference at 0000004c
IP: [<c11287d6>] __gpio_cansleep+0xe/0x1a
*pde = 00000000
Oops: 0000 [#1] SMP
Modules linked in: leds_gpio(+) via_rhine mii cs5535_mfd mfd_core
geode_rng rng_core geode_aes isofs nls_utf8 nls_cp437 vfat fat
ata_generic pata_amd pata_cs5536 pata_acpi libata ehci_pci ehci_hcd
ohci_hcd usb_storage usbcore usb_common sd_mod scsi_mod squashfs loop
Pid: 881, comm: modprobe Not tainted 3.9.2 #1-Alpine
EIP: 0060:[<c11287d6>] EFLAGS: 00010282 CPU: 0
EIP is at __gpio_cansleep+0xe/0x1a
EAX: 00000000 EBX: cf364018 ECX: c132b8b9 EDX: 00000000
ESI: c13993a4 EDI: c1399370 EBP: cded9dbc ESP: cded9dbc
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 8005003b CR2: 0000004c CR3: 0f0c4000 CR4: 00000090
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Process modprobe (pid: 881, ti=cded8000 task=cf094aa0 task.ti=cded8000)
Stack:
 cded9de0 d09471cb 00000000 c1399260 cf364014 00000000 c1399260 c1399254
 d0949014 cded9df4 c118cd59 c1399260 d0949014 d0949014 cded9e08 c118ba47
 c1399260 d0949014 c1399294 cded9e1c c118bb75 cded9e24 d0949014 00000000
Call Trace:
 [<d09471cb>] gpio_led_probe+0xba/0x203 [leds_gpio]
 [<c118cd59>] platform_drv_probe+0x26/0x48
 [<c118ba47>] driver_probe_device+0x75/0x15c
 [<c118bb75>] __driver_attach+0x47/0x63
 [<c118a727>] bus_for_each_dev+0x3c/0x66
 [<c118b6f9>] driver_attach+0x14/0x16
 [<c118bb2e>] ? driver_probe_device+0x15c/0x15c
 [<c118b3d5>] bus_add_driver+0xbd/0x1bc
 [<d08b4000>] ? 0xd08b3fff
 [<d08b4000>] ? 0xd08b3fff
 [<c118bffc>] driver_register+0x74/0xec
 [<d08b4000>] ? 0xd08b3fff
 [<c118c8e8>] platform_driver_register+0x38/0x3a
 [<d08b400d>] gpio_led_driver_init+0xd/0x1000 [leds_gpio]
 [<c100116c>] do_one_initcall+0x6b/0x10f
 [<d08b4000>] ? 0xd08b3fff
 [<c105e918>] load_module+0x1631/0x1907
 [<c10975d6>] ? insert_vmalloc_vmlist+0x14/0x43
 [<c1098d5b>] ? __vmalloc_node_range+0x13e/0x15f
 [<c105ec50>] sys_init_module+0x62/0x77
 [<c1257888>] syscall_call+0x7/0xb
EIP: [<c11287d6>] __gpio_cansleep+0xe/0x1a SS:ESP 0068:cded9dbc
CR2: 000000000000004c
 ---[ end trace 5308fb20d2514822 ]---

Signed-off-by: Timo Teräs <timo.teras@iki.f>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Raphael Assenat <raph@8d.com>
Cc: Trent Piepho <tpiepho@freescale.com>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
With the rwsem lock around
__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT), we
get circular dependency when we call sysfs_remove_group().

 ======================================================
 [ INFO: possible circular locking dependency detected ]
 3.9.0-rc7+ #15 Not tainted
 -------------------------------------------------------
 cat/2387 is trying to acquire lock:
  (&per_cpu(cpu_policy_rwsem, cpu)){+++++.}, at: [<c02f6179>] lock_policy_rwsem_read+0x25/0x34

 but task is already holding lock:
  (s_active#41){++++.+}, at: [<c00f9bf7>] sysfs_read_file+0x4f/0xcc

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

-> #1 (s_active#41){++++.+}:
        [<c0055a79>] lock_acquire+0x61/0xbc
        [<c00fabf1>] sysfs_addrm_finish+0xc1/0x128
        [<c00f9819>] sysfs_hash_and_remove+0x35/0x64
        [<c00fbe6f>] remove_files.isra.0+0x1b/0x24
        [<c00fbea5>] sysfs_remove_group+0x2d/0xa8
        [<c02f9a0b>] cpufreq_governor_interactive+0x13b/0x35c
        [<c02f61df>] __cpufreq_governor+0x2b/0x8c
        [<c02f6579>] __cpufreq_set_policy+0xa9/0xf8
        [<c02f6b75>] store_scaling_governor+0x61/0x100
        [<c02f6f4d>] store+0x39/0x60
        [<c00f9b81>] sysfs_write_file+0xed/0x114
        [<c00b3fd1>] vfs_write+0x65/0xd8
        [<c00b424b>] sys_write+0x2f/0x50
        [<c000cdc1>] ret_fast_syscall+0x1/0x52

-> #0 (&per_cpu(cpu_policy_rwsem, cpu)){+++++.}:
        [<c0055253>] __lock_acquire+0xef3/0x13dc
        [<c0055a79>] lock_acquire+0x61/0xbc
        [<c03ee1f5>] down_read+0x25/0x30
        [<c02f6179>] lock_policy_rwsem_read+0x25/0x34
        [<c02f6edd>] show+0x21/0x58
        [<c00f9c0f>] sysfs_read_file+0x67/0xcc
        [<c00b40a7>] vfs_read+0x63/0xd8
        [<c00b41fb>] sys_read+0x2f/0x50
        [<c000cdc1>] ret_fast_syscall+0x1/0x52

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(s_active#41);
                                lock(&per_cpu(cpu_policy_rwsem, cpu));
                                lock(s_active#41);
   lock(&per_cpu(cpu_policy_rwsem, cpu));

  *** DEADLOCK ***

 2 locks held by cat/2387:
  #0:  (&buffer->mutex){+.+.+.}, at: [<c00f9bcd>] sysfs_read_file+0x25/0xcc
  #1:  (s_active#41){++++.+}, at: [<c00f9bf7>] sysfs_read_file+0x4f/0xcc

 stack backtrace:
 [<c0011d55>] (unwind_backtrace+0x1/0x9c) from [<c03e9a09>] (print_circular_bug+0x19d/0x1e8)
 [<c03e9a09>] (print_circular_bug+0x19d/0x1e8) from [<c0055253>] (__lock_acquire+0xef3/0x13dc)
 [<c0055253>] (__lock_acquire+0xef3/0x13dc) from [<c0055a79>] (lock_acquire+0x61/0xbc)
 [<c0055a79>] (lock_acquire+0x61/0xbc) from [<c03ee1f5>] (down_read+0x25/0x30)
 [<c03ee1f5>] (down_read+0x25/0x30) from [<c02f6179>] (lock_policy_rwsem_read+0x25/0x34)
 [<c02f6179>] (lock_policy_rwsem_read+0x25/0x34) from [<c02f6edd>] (show+0x21/0x58)
 [<c02f6edd>] (show+0x21/0x58) from [<c00f9c0f>] (sysfs_read_file+0x67/0xcc)
 [<c00f9c0f>] (sysfs_read_file+0x67/0xcc) from [<c00b40a7>] (vfs_read+0x63/0xd8)
 [<c00b40a7>] (vfs_read+0x63/0xd8) from [<c00b41fb>] (sys_read+0x2f/0x50)
 [<c00b41fb>] (sys_read+0x2f/0x50) from [<c000cdc1>] (ret_fast_syscall+0x1/0x52)

This lock isn't required while calling __cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT). Remove it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
This manifested as grep failing psuedo-randomly:

-------------->8---------------------
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$
[ARCLinux]$ ip address show lo | grep inet
    inet 127.0.0.1/8 scope host lo
-------------->8---------------------

ARC700 MMU provides fully orthogonal permission bits per page:
Ur, Uw, Ux, Kr, Kw, Kx

The user mode page permission templates used to have all Kernel mode
access bits enabled.
This caused a tricky race condition observed with uClibc buffered file
read and UNIX pipes.

1. Read access to an anon mapped page in libc .bss: write-protected
   zero_page mapped: TLB Entry installed with Ur + K[rwx]

2. grep calls libc:getc() -> buffered read layer calls read(2) with the
   internal read buffer in same .bss page.
   The read() call is on STDIN which has been redirected to a pipe.
   read(2) => sys_read() => pipe_read() => copy_to_user()

3. Since page has Kernel-write permission (despite being user-mode
   write-protected), copy_to_user() suceeds w/o taking a MMU TLB-Miss
   Exception (page-fault for ARC). core-MM is unaware that kernel
   erroneously wrote to the reserved read-only zero-page (BUG #1)

4. Control returns to userspace which now does a write to same .bss page
   Since Linux MM is not aware that page has been modified by kernel, it
   simply reassigns a new writable zero-init page to mapping, loosing the
   prior write by kernel - effectively zero'ing out the libc read buffer
   under the hood - hence grep doesn't see right data (BUG #2)

The fix is to make all kernel-mode access permissions mirror the
user-mode ones. Note that the kernel still has full access to pages,
when accessed directly (w/o MMU) - this fix ensures that kernel-mode
access in copy_to_from() path uses the same faulting access model as for
pure user accesses to keep MM fully aware of page state.

The issue is peudo-random because it only shows up if the TLB entry
installed in #1 is present at the time of #3. If it is evicted out, due
to TLB pressure or some-such, then copy_to_user() does take a TLB Miss
Exception, with a routine write-to-anon COW processing installing a
fresh page for kernel writes and also usable as it is in userspace.

Further the issue was dormant for so long as it depends on where the
libc internal read buffer (in .bss) is mapped at runtime.
If it happens to reside in file-backed data mapping of libc (in the
page-aligned slack space trailing the file backed data), loader zero
padding the slack space, does the early cow page replacement, setting
things up at the very beginning itself.

With gcc 4.8 based builds, the libc buffer got pushed out to a real
anon mapping which triggers the issue.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # 3.9
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
bergwolf pushed a commit that referenced this pull request May 27, 2013
nilfs2: fix issue of nilfs_set_page_dirty for page at EOF boundary

DESCRIPTION:
 There are use-cases when NILFS2 file system (formatted with block size
lesser than 4 KB) can be remounted in RO mode because of encountering of
"broken bmap" issue.

The issue was reported by Anthony Doggett <Anthony2486@interfaces.org.uk>:
 "The machine I've been trialling nilfs on is running Debian Testing,
  Linux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc
  version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.35-2), but I've
  also reproduced it (identically) with Debian Unstable amd64 and Debian
  Experimental (using the 3.8-trunk kernel).  The problematic partitions
  were formatted with "mkfs.nilfs2 -b 1024 -B 8192"."

SYMPTOMS:
(1) System log contains error messages likewise:

    [63102.496756] nilfs_direct_assign: invalid pointer: 0
    [63102.496786] NILFS error (device dm-17): nilfs_bmap_assign: broken bmap (inode number=28)
    [63102.496798]
    [63102.524403] Remounting filesystem read-only

(2) The NILFS2 file system is remounted in RO mode.

REPRODUSING PATH:
(1) Create volume group with name "unencrypted" by means of vgcreate utility.
(2) Run script (prepared by Anthony Doggett <Anthony2486@interfaces.org.uk>):

----------------[BEGIN SCRIPT]--------------------

VG=unencrypted
lvcreate --size 2G --name ntest $VG
mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest
mkdir /var/tmp/n
mkdir /var/tmp/n/ntest
mount /dev/mapper/$VG-ntest /var/tmp/n/ntest
mkdir /var/tmp/n/ntest/thedir
cd /var/tmp/n/ntest/thedir
sleep 2
date
darcs init
sleep 2
dmesg|tail -n 5
date
darcs whatsnew || true
date
sleep 2
dmesg|tail -n 5
----------------[END SCRIPT]--------------------

REPRODUCIBILITY: 100%

INVESTIGATION:
As it was discovered, the issue takes place during segment
construction after executing such sequence of user-space operations:

  open("_darcs/index", O_RDWR|O_CREAT|O_NOCTTY, 0666) = 7
  fstat(7, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
  ftruncate(7, 60)

The error message "NILFS error (device dm-17): nilfs_bmap_assign: broken
bmap (inode number=28)" takes place because of trying to get block
number for third block of the file with logical offset #3072 bytes.  As
it is possible to see from above output, the file has 60 bytes of the
whole size.  So, it is enough one block (1 KB in size) allocation for
the whole file.  Trying to operate with several blocks instead of one
takes place because of discovering several dirty buffers for this file
in nilfs_segctor_scan_file() method.

The root cause of this issue is in nilfs_set_page_dirty function which
is called just before writing to an mmapped page.

When nilfs_page_mkwrite function handles a page at EOF boundary, it
fills hole blocks only inside EOF through __block_page_mkwrite().

The __block_page_mkwrite() function calls set_page_dirty() after filling
hole blocks, thus nilfs_set_page_dirty function (=
a_ops->set_page_dirty) is called.  However, the current implementation
of nilfs_set_page_dirty() wrongly marks all buffers dirty even for page
at EOF boundary.

As a result, buffers outside EOF are inconsistently marked dirty and
queued for write even though they are not mapped with nilfs_get_block
function.

FIX:
This modifies nilfs_set_page_dirty() not to mark hole blocks dirty.

Thanks to Vyacheslav Dubeyko for his effort on analysis and proposals
for this issue.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reported-by: Anthony Doggett <Anthony2486@interfaces.org.uk>
Reported-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
@bergwolf bergwolf closed this May 27, 2013
bergwolf added a commit that referenced this pull request May 28, 2013
Got bellow lockdep warning during tests. It is false alarm though.

[ 1184.479097] =============================================
[ 1184.479187] [ INFO: possible recursive locking detected ]
[ 1184.479277] 3.10.0-rc3+ #13 Tainted: G         C
[ 1184.479355] ---------------------------------------------
[ 1184.479444] mkdir/2215 is trying to acquire lock:
[ 1184.479521]  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc27c>] ll_md_blocking_ast+0x55c/0x655 [lustre]
[ 1184.479801]
but task is already holding lock:
[ 1184.479895]  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc1b1>] ll_md_blocking_ast+0x491/0x655 [lustre]
[ 1184.480101]
other info that might help us debug this:
[ 1184.480206]  Possible unsafe locking scenario:

[ 1184.480300]        CPU0
[ 1184.480340]        ----
[ 1184.480380]   lock(&(&dentry->d_lock)->rlock);
[ 1184.480458]   lock(&(&dentry->d_lock)->rlock);
[ 1184.480536]
 *** DEADLOCK ***

[ 1184.480761]  May be due to missing lock nesting notation

[ 1184.480936] 4 locks held by mkdir/2215:
[ 1184.481037]  #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff811531a9>] mnt_want_write+0x24/0x4b
[ 1184.481273]  #1:  (&type->i_mutex_dir_key#3/1){+.+.+.}, at: [<ffffffff81144fce>] kern_path_create+0x8c/0x144
[ 1184.481513]  #2:  (&sb->s_type->i_lock_key#19){+.+...}, at: [<ffffffffa06cc180>] ll_md_blocking_ast+0x460/0x655 [lustre]
[ 1184.481778]  #3:  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc1b1>] ll_md_blocking_ast+0x491/0x655 [lustre]
[ 1184.482050]

Signed-off-by: Peng Tao <tao.peng@emc.com>
bergwolf pushed a commit that referenced this pull request May 28, 2013
Toralf reported the following oops to the linux-nfs mailing list:

    -----------------[snip]------------------
    NFSD: unable to generate recoverydir name (-2).
    NFSD: disabling legacy clientid tracking. Reboot recovery will not function correctly!
    BUG: unable to handle kernel NULL pointer dereference at 000003c8
    IP: [<f90a3d91>] nfsd4_client_tracking_exit+0x11/0x50 [nfsd]
    *pdpt = 000000002ba33001 *pde = 0000000000000000
    Oops: 0000 [#1] SMP
    Modules linked in: loop nfsd auth_rpcgss ipt_MASQUERADE xt_owner xt_multiport ipt_REJECT xt_tcpudp xt_recent xt_conntrack nf_conntrack_ftp xt_limit xt_LOG iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_filter ip_tables x_tables af_packet pppoe pppox ppp_generic slhc bridge stp llc tun arc4 iwldvm mac80211 coretemp kvm_intel uvcvideo sdhci_pci sdhci mmc_core videobuf2_vmalloc videobuf2_memops usblp videobuf2_core i915 iwlwifi psmouse videodev cfg80211 kvm fbcon bitblit cfbfillrect acpi_cpufreq mperf evdev softcursor font cfbimgblt i2c_algo_bit cfbcopyarea intel_agp intel_gtt drm_kms_helper snd_hda_codec_conexant drm agpgart fb fbdev tpm_tis thinkpad_acpi tpm nvram e1000e rfkill thermal ptp wmi pps_core tpm_bios 8250_pci processor 8250 ac snd_hda_intel snd_hda_codec snd_pcm battery video i2c_i801 snd_page_alloc snd_timer button serial_core i2c_core snd soundcore thermal_sys hwmon aesni_intel ablk_helper cryp
td lrw aes_i586 xts gf128mul cbc fuse nfs lockd sunrpc dm_crypt dm_mod hid_monterey hid_microsoft hid_logitech hid_ezkey hid_cypress hid_chicony hid_cherry hid_belkin hid_apple hid_a4tech hid_generic usbhid hid sr_mod cdrom sg [last unloaded: microcode]
    Pid: 6374, comm: nfsd Not tainted 3.9.1 #6 LENOVO 4180F65/4180F65
    EIP: 0060:[<f90a3d91>] EFLAGS: 00010202 CPU: 0
    EIP is at nfsd4_client_tracking_exit+0x11/0x50 [nfsd]
    EAX: 00000000 EBX: fffffffe ECX: 00000007 EDX: 00000007
    ESI: eb9dcb00 EDI: eb2991c0 EBP: eb2bde38 ESP: eb2bde34
    DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
    CR0: 80050033 CR2: 000003c8 CR3: 2ba80000 CR4: 000407f0
    DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
    DR6: ffff0ff0 DR7: 00000400
    Process nfsd (pid: 6374, ti=eb2bc000 task=eb2711c0 task.ti=eb2bc000)
    Stack:
    fffffffe eb2bde4c f90a3e0c f90a7754 fffffffe eb0a9c00 eb2bdea0 f90a41ed
    eb2991c0 1b270000 eb2991c0 eb2bde7c f9099ce9 eb2bde98 0129a020 eb29a020
    eb2bdecc eb2991c0 eb2bdea8 f9099da5 00000000 eb9dcb00 00000001 67822f08
    Call Trace:
    [<f90a3e0c>] legacy_recdir_name_error+0x3c/0x40 [nfsd]
    [<f90a41ed>] nfsd4_create_clid_dir+0x15d/0x1c0 [nfsd]
    [<f9099ce9>] ? nfsd4_lookup_stateid+0x99/0xd0 [nfsd]
    [<f9099da5>] ? nfs4_preprocess_seqid_op+0x85/0x100 [nfsd]
    [<f90a4287>] nfsd4_client_record_create+0x37/0x50 [nfsd]
    [<f909d6ce>] nfsd4_open_confirm+0xfe/0x130 [nfsd]
    [<f90980b1>] ? nfsd4_encode_operation+0x61/0x90 [nfsd]
    [<f909d5d0>] ? nfsd4_free_stateid+0xc0/0xc0 [nfsd]
    [<f908fd0b>] nfsd4_proc_compound+0x41b/0x530 [nfsd]
    [<f9081b7b>] nfsd_dispatch+0x8b/0x1a0 [nfsd]
    [<f857b85d>] svc_process+0x3dd/0x640 [sunrpc]
    [<f908165d>] nfsd+0xad/0x110 [nfsd]
    [<f90815b0>] ? nfsd_destroy+0x70/0x70 [nfsd]
    [<c1054824>] kthread+0x94/0xa0
    [<c1486937>] ret_from_kernel_thread+0x1b/0x28
    [<c1054790>] ? flush_kthread_work+0xd0/0xd0
    Code: 86 b0 00 00 00 90 c5 0a f9 c7 04 24 70 76 0a f9 e8 74 a9 3d c8 eb ba 8d 76 00 55 89 e5 53 66 66 66 66 90 8b 15 68 c7 0a f9 85 d2 <8b> 88 c8 03 00 00 74 2c 3b 11 77 28 8b 5c 91 08 85 db 74 22 8b
    EIP: [<f90a3d91>] nfsd4_client_tracking_exit+0x11/0x50 [nfsd] SS:ESP 0068:eb2bde34
    CR2: 00000000000003c8
    ---[ end trace 09e54015d145c9c6 ]---

The problem appears to be a regression that was introduced in commit
9a9c647 "nfsd: make NFSv4 recovery client tracking options per net".
Prior to that commit, it was safe to pass a NULL net pointer to
nfsd4_client_tracking_exit in the legacy recdir case, and
legacy_recdir_name_error did so. After that comit, the net pointer must
be valid.

This patch just fixes legacy_recdir_name_error to pass in a valid net
pointer to that function.

Cc: <stable@vger.kernel.org> # v3.8+
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Reported-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
bergwolf pushed a commit that referenced this pull request May 28, 2013
… size

Dave reported an oops triggered by trinity:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: newseg+0x10d/0x390
  PGD cf8c1067 PUD cf8c2067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  CPU: 2 PID: 7636 Comm: trinity-child2 Not tainted 3.9.0+#67
  ...
  Call Trace:
    ipcget+0x182/0x380
    SyS_shmget+0x5a/0x60
    tracesys+0xdd/0xe2

This bug was introduced by commit af73e4d ("hugetlbfs: fix mmap
failure in unaligned size request").

Reported-by: Dave Jones <davej@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Li Zefan <lizfan@huawei.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bergwolf pushed a commit that referenced this pull request May 28, 2013
Cleanup regex_lock and ftrace_lock locking points around
ftrace_ops hash update code.

The new rule is that regex_lock protects ops->*_hash
read-update-write code for each ftrace_ops. Usually,
hash update is done by following sequence.

1. allocate a new local hash and copy the original hash.
2. update the local hash.
3. move(actually, copy) back the local hash to ftrace_ops.
4. update ftrace entries if needed.
5. release the local hash.

This makes regex_lock protect #1-#4, and ftrace_lock
to protect #3, #4 and adding and removing ftrace_ops from the
ftrace_ops_list. The ftrace_lock protects #3 as well because
the move functions update the entries too.

Link: http://lkml.kernel.org/r/20130509054421.30398.83411.stgit@mhiramat-M0-7522

Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
bergwolf added a commit that referenced this pull request May 29, 2013
Got bellow lockdep warning during tests. It is false alarm though.

[ 1184.479097] =============================================
[ 1184.479187] [ INFO: possible recursive locking detected ]
[ 1184.479277] 3.10.0-rc3+ #13 Tainted: G         C
[ 1184.479355] ---------------------------------------------
[ 1184.479444] mkdir/2215 is trying to acquire lock:
[ 1184.479521]  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc27c>] ll_md_blocking_ast+0x55c/0x655 [lustre]
[ 1184.479801]
but task is already holding lock:
[ 1184.479895]  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc1b1>] ll_md_blocking_ast+0x491/0x655 [lustre]
[ 1184.480101]
other info that might help us debug this:
[ 1184.480206]  Possible unsafe locking scenario:

[ 1184.480300]        CPU0
[ 1184.480340]        ----
[ 1184.480380]   lock(&(&dentry->d_lock)->rlock);
[ 1184.480458]   lock(&(&dentry->d_lock)->rlock);
[ 1184.480536]
 *** DEADLOCK ***

[ 1184.480761]  May be due to missing lock nesting notation

[ 1184.480936] 4 locks held by mkdir/2215:
[ 1184.481037]  #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff811531a9>] mnt_want_write+0x24/0x4b
[ 1184.481273]  #1:  (&type->i_mutex_dir_key#3/1){+.+.+.}, at: [<ffffffff81144fce>] kern_path_create+0x8c/0x144
[ 1184.481513]  #2:  (&sb->s_type->i_lock_key#19){+.+...}, at: [<ffffffffa06cc180>] ll_md_blocking_ast+0x460/0x655 [lustre]
[ 1184.481778]  #3:  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc1b1>] ll_md_blocking_ast+0x491/0x655 [lustre]
[ 1184.482050]

Signed-off-by: Peng Tao <tao.peng@emc.com>
bergwolf added a commit that referenced this pull request May 30, 2013
Got bellow lockdep warning during tests. It is false alarm though.

[ 1184.479097] =============================================
[ 1184.479187] [ INFO: possible recursive locking detected ]
[ 1184.479277] 3.10.0-rc3+ #13 Tainted: G         C
[ 1184.479355] ---------------------------------------------
[ 1184.479444] mkdir/2215 is trying to acquire lock:
[ 1184.479521]  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc27c>] ll_md_blocking_ast+0x55c/0x655 [lustre]
[ 1184.479801]
but task is already holding lock:
[ 1184.479895]  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc1b1>] ll_md_blocking_ast+0x491/0x655 [lustre]
[ 1184.480101]
other info that might help us debug this:
[ 1184.480206]  Possible unsafe locking scenario:

[ 1184.480300]        CPU0
[ 1184.480340]        ----
[ 1184.480380]   lock(&(&dentry->d_lock)->rlock);
[ 1184.480458]   lock(&(&dentry->d_lock)->rlock);
[ 1184.480536]
 *** DEADLOCK ***

[ 1184.480761]  May be due to missing lock nesting notation

[ 1184.480936] 4 locks held by mkdir/2215:
[ 1184.481037]  #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff811531a9>] mnt_want_write+0x24/0x4b
[ 1184.481273]  #1:  (&type->i_mutex_dir_key#3/1){+.+.+.}, at: [<ffffffff81144fce>] kern_path_create+0x8c/0x144
[ 1184.481513]  #2:  (&sb->s_type->i_lock_key#19){+.+...}, at: [<ffffffffa06cc180>] ll_md_blocking_ast+0x460/0x655 [lustre]
[ 1184.481778]  #3:  (&(&dentry->d_lock)->rlock){+.+...}, at: [<ffffffffa06cc1b1>] ll_md_blocking_ast+0x491/0x655 [lustre]
[ 1184.482050]

Signed-off-by: Peng Tao <tao.peng@emc.com>
bergwolf pushed a commit that referenced this pull request Jun 3, 2013
Don't sleep in __fscache_maybe_release_page() if __GFP_FS is not set.  This
goes some way towards mitigating fscache deadlocking against ext4 by way of
the allocator, eg:

INFO: task flush-8:0:24427 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
flush-8:0       D ffff88003e2b9fd8     0 24427      2 0x00000000
 ffff88003e2b9138 0000000000000046 ffff880012e3a040 ffff88003e2b9fd8
 0000000000011c80 ffff88003e2b9fd8 ffffffff81a10400 ffff880012e3a040
 0000000000000002 ffff880012e3a040 ffff88003e2b9098 ffffffff8106dcf5
Call Trace:
 [<ffffffff8106dcf5>] ? __lock_is_held+0x31/0x53
 [<ffffffff81219b61>] ? radix_tree_lookup_element+0xf4/0x12a
 [<ffffffff81454bed>] schedule+0x60/0x62
 [<ffffffffa01d349c>] __fscache_wait_on_page_write+0x8b/0xa5 [fscache]
 [<ffffffff810498a8>] ? __init_waitqueue_head+0x4d/0x4d
 [<ffffffffa01d393a>] __fscache_maybe_release_page+0x30c/0x324 [fscache]
 [<ffffffffa01d369a>] ? __fscache_maybe_release_page+0x6c/0x324 [fscache]
 [<ffffffff81071b53>] ? trace_hardirqs_on_caller+0x114/0x170
 [<ffffffffa01fd7b2>] nfs_fscache_release_page+0x68/0x94 [nfs]
 [<ffffffffa01ef73e>] nfs_release_page+0x7e/0x86 [nfs]
 [<ffffffff810aa553>] try_to_release_page+0x32/0x3b
 [<ffffffff810b6c70>] shrink_page_list+0x535/0x71a
 [<ffffffff81071b53>] ? trace_hardirqs_on_caller+0x114/0x170
 [<ffffffff810b7352>] shrink_inactive_list+0x20a/0x2dd
 [<ffffffff81071a13>] ? mark_held_locks+0xbe/0xea
 [<ffffffff810b7a65>] shrink_lruvec+0x34c/0x3eb
 [<ffffffff810b7bd3>] do_try_to_free_pages+0xcf/0x355
 [<ffffffff810b7fc8>] try_to_free_pages+0x9a/0xa1
 [<ffffffff810b08d2>] __alloc_pages_nodemask+0x494/0x6f7
 [<ffffffff810d9a07>] kmem_getpages+0x58/0x155
 [<ffffffff810dc002>] fallback_alloc+0x120/0x1f3
 [<ffffffff8106db23>] ? trace_hardirqs_off+0xd/0xf
 [<ffffffff810dbed3>] ____cache_alloc_node+0x177/0x186
 [<ffffffff81162a6c>] ? ext4_init_io_end+0x1c/0x37
 [<ffffffff810dc403>] kmem_cache_alloc+0xf1/0x176
 [<ffffffff810b17ac>] ? test_set_page_writeback+0x101/0x113
 [<ffffffff81162a6c>] ext4_init_io_end+0x1c/0x37
 [<ffffffff81162ce4>] ext4_bio_write_page+0x20f/0x3af
 [<ffffffff8115cc02>] mpage_da_submit_io+0x26e/0x2f6
 [<ffffffff811088e5>] ? __find_get_block_slow+0x38/0x133
 [<ffffffff81161348>] mpage_da_map_and_submit+0x3a7/0x3bd
 [<ffffffff81161a60>] ext4_da_writepages+0x30d/0x426
 [<ffffffff810b3359>] do_writepages+0x1c/0x2a
 [<ffffffff81102f4d>] __writeback_single_inode+0x3e/0xe5
 [<ffffffff81103995>] writeback_sb_inodes+0x1bd/0x2f4
 [<ffffffff81103b3b>] __writeback_inodes_wb+0x6f/0xb4
 [<ffffffff81103c81>] wb_writeback+0x101/0x195
 [<ffffffff81071b53>] ? trace_hardirqs_on_caller+0x114/0x170
 [<ffffffff811043aa>] ? wb_do_writeback+0xaa/0x173
 [<ffffffff8110434a>] wb_do_writeback+0x4a/0x173
 [<ffffffff81071bbc>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffff81038554>] ? del_timer+0x4b/0x5b
 [<ffffffff811044e0>] bdi_writeback_thread+0x6d/0x147
 [<ffffffff81104473>] ? wb_do_writeback+0x173/0x173
 [<ffffffff81048fbc>] kthread+0xd0/0xd8
 [<ffffffff81455eb2>] ? _raw_spin_unlock_irq+0x29/0x3e
 [<ffffffff81048eec>] ? __init_kthread_worker+0x55/0x55
 [<ffffffff81456aac>] ret_from_fork+0x7c/0xb0
 [<ffffffff81048eec>] ? __init_kthread_worker+0x55/0x55
2 locks held by flush-8:0/24427:
 #0:  (&type->s_umount_key#41){.+.+..}, at: [<ffffffff810e3b73>] grab_super_passive+0x4c/0x76
 #1:  (jbd2_handle){+.+...}, at: [<ffffffff81190d81>] start_this_handle+0x475/0x4ea


The problem here is that another thread, which is attempting to write the
to-be-stored NFS page to the on-ext4 cache file is waiting for the journal
lock, eg:

INFO: task kworker/u:2:24437 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u:2     D ffff880039589768     0 24437      2 0x00000000
 ffff8800395896d8 0000000000000046 ffff8800283bf040 ffff880039589fd8
 0000000000011c80 ffff880039589fd8 ffff880039f0b040 ffff8800283bf040
 0000000000000006 ffff8800283bf6b8 ffff880039589658 ffffffff81071a13
Call Trace:
 [<ffffffff81071a13>] ? mark_held_locks+0xbe/0xea
 [<ffffffff81455e73>] ? _raw_spin_unlock_irqrestore+0x3a/0x50
 [<ffffffff81071b53>] ? trace_hardirqs_on_caller+0x114/0x170
 [<ffffffff81071bbc>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffff81454bed>] schedule+0x60/0x62
 [<ffffffff81190c23>] start_this_handle+0x317/0x4ea
 [<ffffffff810498a8>] ? __init_waitqueue_head+0x4d/0x4d
 [<ffffffff81190fcc>] jbd2__journal_start+0xb3/0x12e
 [<ffffffff81176606>] __ext4_journal_start_sb+0xb2/0xc6
 [<ffffffff8115f137>] ext4_da_write_begin+0x109/0x233
 [<ffffffff810a964d>] generic_file_buffered_write+0x11a/0x264
 [<ffffffff811032cf>] ? __mark_inode_dirty+0x2d/0x1ee
 [<ffffffff810ab1ab>] __generic_file_aio_write+0x2a5/0x2d5
 [<ffffffff810ab24a>] generic_file_aio_write+0x6f/0xd0
 [<ffffffff81159a2c>] ext4_file_write+0x38c/0x3c4
 [<ffffffff810e0915>] do_sync_write+0x91/0xd1
 [<ffffffffa00a17f0>] cachefiles_write_page+0x26f/0x310 [cachefiles]
 [<ffffffffa01d470b>] fscache_write_op+0x21e/0x37a [fscache]
 [<ffffffff81455eb2>] ? _raw_spin_unlock_irq+0x29/0x3e
 [<ffffffffa01d2479>] fscache_op_work_func+0x78/0xd7 [fscache]
 [<ffffffff8104455a>] process_one_work+0x232/0x3a8
 [<ffffffff810444ff>] ? process_one_work+0x1d7/0x3a8
 [<ffffffff81044ee0>] worker_thread+0x214/0x303
 [<ffffffff81044ccc>] ? manage_workers+0x245/0x245
 [<ffffffff81048fbc>] kthread+0xd0/0xd8
 [<ffffffff81455eb2>] ? _raw_spin_unlock_irq+0x29/0x3e
 [<ffffffff81048eec>] ? __init_kthread_worker+0x55/0x55
 [<ffffffff81456aac>] ret_from_fork+0x7c/0xb0
 [<ffffffff81048eec>] ? __init_kthread_worker+0x55/0x55
4 locks held by kworker/u:2/24437:
 #0:  (fscache_operation){.+.+.+}, at: [<ffffffff810444ff>] process_one_work+0x1d7/0x3a8
 #1:  ((&op->work)){+.+.+.}, at: [<ffffffff810444ff>] process_one_work+0x1d7/0x3a8
 #2:  (sb_writers#14){.+.+.+}, at: [<ffffffff810ab22c>] generic_file_aio_write+0x51/0xd0
 #3:  (&sb->s_type->i_mutex_key#19){+.+.+.}, at: [<ffffffff810ab236>] generic_file_aio_write+0x5b/0x

fscache already tries to cancel pending stores, but it can't cancel a write
for which I/O is already in progress.

An alternative would be to accept writing garbage to the cache under extreme
circumstances and to kill the afflicted cache object if we have to do this.
However, we really need to know how strapped the allocator is before deciding
to do that.

Signed-off-by: David Howells <dhowells@redhat.com>
bergwolf pushed a commit that referenced this pull request Jun 3, 2013
Accessing the OTP memory on AR9950 causes a data bus
like this:

  Data bus error, epc == 801f7774, ra == 801f7774
  Oops[#1]:
  CPU: 0 PID: 1 Comm: swapper Not tainted 3.10.0-rc3 #592
  task: 87c28000 ti: 87c22000 task.ti: 87c22000
  $ 0   : 00000000 00000061 deadc0de 00000000
  $ 4   : b8115f18 00015f18 00000007 00000004
  $ 8   : 00000001 7c7c3c7c 7c7c7c7c 7c7c7c7c
  $12   : 7c7c3c7c 80320a68 00000000 7c7c7c3c
  $16   : 87cd8010 00015f18 00000007 00000000
  $20   : 00000064 00000004 87c23c7c 8035210c
  $24   : 00000000 801f3674
  $28   : 87c22000 87c23b48 00000001 801f7774
  Hi    : 00000000
  Lo    : 00000064
  epc   : 801f7774 ath9k_hw_wait+0x58/0xb0
      Not tainted
  ra    : 801f7774 ath9k_hw_wait+0x58/0xb0
  Status: 1000cc03 KERNEL EXL IE
  Cause : 4080801c
  PrId  : 00019750 (MIPS 74Kc)
  Modules linked in:
  Process swapper (pid: 1, threadinfo=87c22000, task=87c28000, ts=00000000)
  Stack : 0000000f 00000061 00002710 8006240c 00000001 87cd8010 87c23bb0 87cd8010
          00000000 00000004 00000003 80210c7c 000000b3 67fa800 0000032a 000006fe
          000003e8 00000002 00000028 87c23bf0 000003ff 80210d24 803e5630 80210e28
          00000000 00000007 87cd8010 0000704 00000004 00000061 000003ff 000001ff
          87c26000 87cd8010 00000220 87cd8bb8 80210000 8020fcf4 87c22000 87c23c08
          ...
  Call Trace:
  [<801f7774>] ath9k_hw_wait+0x58/0xb0
  [<80210c7c>] ar9300_otp_read_word+0x80/0xd4
  [<80210d24>] ar9300_read_otp+0x54/0xb0
  [<8020fcf4>] ar9300_check_eeprom_header+0x1c/0x40
  [<80210fe4>] ath9k_hw_ar9300_fill_eeprom+0x118/0x39c
  [<80206650>] ath9k_hw_eeprom_init+0x74/0xb4
  [<801f96d0>] ath9k_hw_init+0x7ec/0x96c
  [<801e65ec>] ath9k_init_device+0x340/0x758
  [<801f35d0>] ath_ahb_probe+0x21c/0x2c0
  [<801c041c>] driver_probe_device+0xc0/0x1e4
  [<801c05ac>] __driver_attach+0x6c/0xa4
  [<801bea08>] bus_for_each_dev+0x64/0xa8
  [<801bfa40>] bus_add_driver+0xcc/0x24c
  [<801c0954>] driver_register+0xbc/0x17c
  [<803f8fc0>] ath9k_init+0x5c/0x88
  [<800608fc>] do_one_initcall+0xec/0x1a0
  [<803e6a68>] kernel_init_freeable+0x13c/0x200
  [<80309cdc>] kernel_init+0x1c/0xe4
  [<80062450>] ret_from_kernel_thread+0x10/0x18

On the AR9550, the OTP registers are located at
the same address as on the AR9340. Use the correct
values to avoid the error.

Cc: stable@vger.kernel.org  # 3.6+
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
bergwolf pushed a commit that referenced this pull request Jun 3, 2013
This commit fixes a lockdep-detected deadlock by moving a wake_up()
call out from a rnp->lock critical section.  Please see below for
the long version of this story.

On Tue, 2013-05-28 at 16:13 -0400, Dave Jones wrote:

> [12572.705832] ======================================================
> [12572.750317] [ INFO: possible circular locking dependency detected ]
> [12572.796978] 3.10.0-rc3+ #39 Not tainted
> [12572.833381] -------------------------------------------------------
> [12572.862233] trinity-child17/31341 is trying to acquire lock:
> [12572.870390]  (rcu_node_0){..-.-.}, at: [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0
> [12572.878859]
> but task is already holding lock:
> [12572.894894]  (&ctx->lock){-.-...}, at: [<ffffffff811390ed>] perf_lock_task_context+0x7d/0x2d0
> [12572.903381]
> which lock already depends on the new lock.
>
> [12572.927541]
> the existing dependency chain (in reverse order) is:
> [12572.943736]
> -> #4 (&ctx->lock){-.-...}:
> [12572.960032]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12572.968337]        [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12572.976633]        [<ffffffff8113c987>] __perf_event_task_sched_out+0x2e7/0x5e0
> [12572.984969]        [<ffffffff81088953>] perf_event_task_sched_out+0x93/0xa0
> [12572.993326]        [<ffffffff816ea0bf>] __schedule+0x2cf/0x9c0
> [12573.001652]        [<ffffffff816eacfe>] schedule_user+0x2e/0x70
> [12573.009998]        [<ffffffff816ecd64>] retint_careful+0x12/0x2e
> [12573.018321]
> -> #3 (&rq->lock){-.-.-.}:
> [12573.034628]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.042930]        [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12573.051248]        [<ffffffff8108e6a7>] wake_up_new_task+0xb7/0x260
> [12573.059579]        [<ffffffff810492f5>] do_fork+0x105/0x470
> [12573.067880]        [<ffffffff81049686>] kernel_thread+0x26/0x30
> [12573.076202]        [<ffffffff816cee63>] rest_init+0x23/0x140
> [12573.084508]        [<ffffffff81ed8e1f>] start_kernel+0x3f1/0x3fe
> [12573.092852]        [<ffffffff81ed856f>] x86_64_start_reservations+0x2a/0x2c
> [12573.101233]        [<ffffffff81ed863d>] x86_64_start_kernel+0xcc/0xcf
> [12573.109528]
> -> #2 (&p->pi_lock){-.-.-.}:
> [12573.125675]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.133829]        [<ffffffff816ebe9b>] _raw_spin_lock_irqsave+0x4b/0x90
> [12573.141964]        [<ffffffff8108e881>] try_to_wake_up+0x31/0x320
> [12573.150065]        [<ffffffff8108ebe2>] default_wake_function+0x12/0x20
> [12573.158151]        [<ffffffff8107bbf8>] autoremove_wake_function+0x18/0x40
> [12573.166195]        [<ffffffff81085398>] __wake_up_common+0x58/0x90
> [12573.174215]        [<ffffffff81086909>] __wake_up+0x39/0x50
> [12573.182146]        [<ffffffff810fc3da>] rcu_start_gp_advanced.isra.11+0x4a/0x50
> [12573.190119]        [<ffffffff810fdb09>] rcu_start_future_gp+0x1c9/0x1f0
> [12573.198023]        [<ffffffff810fe2c4>] rcu_nocb_kthread+0x114/0x930
> [12573.205860]        [<ffffffff8107a91d>] kthread+0xed/0x100
> [12573.213656]        [<ffffffff816f4b1c>] ret_from_fork+0x7c/0xb0
> [12573.221379]
> -> #1 (&rsp->gp_wq){..-.-.}:
> [12573.236329]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.243783]        [<ffffffff816ebe9b>] _raw_spin_lock_irqsave+0x4b/0x90
> [12573.251178]        [<ffffffff810868f3>] __wake_up+0x23/0x50
> [12573.258505]        [<ffffffff810fc3da>] rcu_start_gp_advanced.isra.11+0x4a/0x50
> [12573.265891]        [<ffffffff810fdb09>] rcu_start_future_gp+0x1c9/0x1f0
> [12573.273248]        [<ffffffff810fe2c4>] rcu_nocb_kthread+0x114/0x930
> [12573.280564]        [<ffffffff8107a91d>] kthread+0xed/0x100
> [12573.287807]        [<ffffffff816f4b1c>] ret_from_fork+0x7c/0xb0

Notice the above call chain.

rcu_start_future_gp() is called with the rnp->lock held. Then it calls
rcu_start_gp_advance, which does a wakeup.

You can't do wakeups while holding the rnp->lock, as that would mean
that you could not do a rcu_read_unlock() while holding the rq lock, or
any lock that was taken while holding the rq lock. This is because...
(See below).

> [12573.295067]
> -> #0 (rcu_node_0){..-.-.}:
> [12573.309293]        [<ffffffff810b8d36>] __lock_acquire+0x1786/0x1af0
> [12573.316568]        [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.323825]        [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12573.331081]        [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0
> [12573.338377]        [<ffffffff810760a6>] __rcu_read_unlock+0x96/0xa0
> [12573.345648]        [<ffffffff811391b3>] perf_lock_task_context+0x143/0x2d0
> [12573.352942]        [<ffffffff8113938e>] find_get_context+0x4e/0x1f0
> [12573.360211]        [<ffffffff811403f4>] SYSC_perf_event_open+0x514/0xbd0
> [12573.367514]        [<ffffffff81140e49>] SyS_perf_event_open+0x9/0x10
> [12573.374816]        [<ffffffff816f4dd4>] tracesys+0xdd/0xe2

Notice the above trace.

perf took its own ctx->lock, which can be taken while holding the rq
lock. While holding this lock, it did a rcu_read_unlock(). The
perf_lock_task_context() basically looks like:

rcu_read_lock();
raw_spin_lock(ctx->lock);
rcu_read_unlock();

Now, what looks to have happened, is that we scheduled after taking that
first rcu_read_lock() but before taking the spin lock. When we scheduled
back in and took the ctx->lock, the following rcu_read_unlock()
triggered the "special" code.

The rcu_read_unlock_special() takes the rnp->lock, which gives us a
possible deadlock scenario.

	CPU0		CPU1		CPU2
	----		----		----

				     rcu_nocb_kthread()
    lock(rq->lock);
		    lock(ctx->lock);
				     lock(rnp->lock);

				     wake_up();

				     lock(rq->lock);

		    rcu_read_unlock();

		    rcu_read_unlock_special();

		    lock(rnp->lock);
    lock(ctx->lock);

**** DEADLOCK ****

> [12573.382068]
> other info that might help us debug this:
>
> [12573.403229] Chain exists of:
>   rcu_node_0 --> &rq->lock --> &ctx->lock
>
> [12573.424471]  Possible unsafe locking scenario:
>
> [12573.438499]        CPU0                    CPU1
> [12573.445599]        ----                    ----
> [12573.452691]   lock(&ctx->lock);
> [12573.459799]                                lock(&rq->lock);
> [12573.467010]                                lock(&ctx->lock);
> [12573.474192]   lock(rcu_node_0);
> [12573.481262]
>  *** DEADLOCK ***
>
> [12573.501931] 1 lock held by trinity-child17/31341:
> [12573.508990]  #0:  (&ctx->lock){-.-...}, at: [<ffffffff811390ed>] perf_lock_task_context+0x7d/0x2d0
> [12573.516475]
> stack backtrace:
> [12573.530395] CPU: 1 PID: 31341 Comm: trinity-child17 Not tainted 3.10.0-rc3+ #39
> [12573.545357]  ffffffff825b4f90 ffff880219f1dbc0 ffffffff816e375b ffff880219f1dc00
> [12573.552868]  ffffffff816dfa5d ffff880219f1dc50 ffff88023ce4d1f8 ffff88023ce4ca40
> [12573.560353]  0000000000000001 0000000000000001 ffff88023ce4d1f8 ffff880219f1dcc0
> [12573.567856] Call Trace:
> [12573.575011]  [<ffffffff816e375b>] dump_stack+0x19/0x1b
> [12573.582284]  [<ffffffff816dfa5d>] print_circular_bug+0x200/0x20f
> [12573.589637]  [<ffffffff810b8d36>] __lock_acquire+0x1786/0x1af0
> [12573.596982]  [<ffffffff810918f5>] ? sched_clock_cpu+0xb5/0x100
> [12573.604344]  [<ffffffff810b9851>] lock_acquire+0x91/0x1f0
> [12573.611652]  [<ffffffff811054ff>] ? rcu_read_unlock_special+0x9f/0x4c0
> [12573.619030]  [<ffffffff816ebc90>] _raw_spin_lock+0x40/0x80
> [12573.626331]  [<ffffffff811054ff>] ? rcu_read_unlock_special+0x9f/0x4c0
> [12573.633671]  [<ffffffff811054ff>] rcu_read_unlock_special+0x9f/0x4c0
> [12573.640992]  [<ffffffff811390ed>] ? perf_lock_task_context+0x7d/0x2d0
> [12573.648330]  [<ffffffff810b429e>] ? put_lock_stats.isra.29+0xe/0x40
> [12573.655662]  [<ffffffff813095a0>] ? delay_tsc+0x90/0xe0
> [12573.662964]  [<ffffffff810760a6>] __rcu_read_unlock+0x96/0xa0
> [12573.670276]  [<ffffffff811391b3>] perf_lock_task_context+0x143/0x2d0
> [12573.677622]  [<ffffffff81139070>] ? __perf_event_enable+0x370/0x370
> [12573.684981]  [<ffffffff8113938e>] find_get_context+0x4e/0x1f0
> [12573.692358]  [<ffffffff811403f4>] SYSC_perf_event_open+0x514/0xbd0
> [12573.699753]  [<ffffffff8108cd9d>] ? get_parent_ip+0xd/0x50
> [12573.707135]  [<ffffffff810b71fd>] ? trace_hardirqs_on_caller+0xfd/0x1c0
> [12573.714599]  [<ffffffff81140e49>] SyS_perf_event_open+0x9/0x10
> [12573.721996]  [<ffffffff816f4dd4>] tracesys+0xdd/0xe2

This commit delays the wakeup via irq_work(), which is what
perf and ftrace use to perform wakeups in critical sections.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
bergwolf pushed a commit that referenced this pull request Jun 3, 2013
"Problems" with the current code:

1: there is a lack of synchronization in setting ->high and ->batch in
   percpu_pagelist_fraction_sysctl_handler()

2: stop_machine() in zone_pcp_update() is unnecissary.

3: zone_pcp_update() does not consider the case where
   percpu_pagelist_fraction is non-zero

To fix:

1: add memory barriers, a safe ->batch value, an update side mutex when
   updating ->high and ->batch, and use ACCESS_ONCE() for ->batch users
   that expect a stable value.

2: avoid draining pages in zone_pcp_update(), rely upon the memory
   barriers added to fix #1

3: factor out quite a few functions, and then call the appropriate one.

Note that it results in a change to the behavior of zone_pcp_update(),
which is used by memory_hotplug.  I'm rather certain that I've diserned
(and preserved) the essential behavior (changing ->high and ->batch), and
only eliminated unneeded actions (draining the per cpu pages), but this
may not be the case.

Further note that the draining of pages that previously took place in
zone_pcp_update() occured after repeated draining when attempting to
offline a page, and after the offline has "succeeded".  It appears that
the draining was added to zone_pcp_update() to avoid refactoring
setup_pageset() into 2 funtions.

This patch:

Creates pageset_set_batch() for use in setup_pageset().
pageset_set_batch() imitates the functionality of
setup_pagelist_highmark(), but uses the boot time
(percpu_pagelist_fraction == 0) calculations for determining ->high based
on ->batch.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Aug 14, 2025
The existing code move the VF NIC to new namespace when NETDEV_REGISTER is
received on netvsc NIC. During deletion of the namespace,
default_device_exit_batch() >> default_device_exit_net() is called. When
netvsc NIC is moved back and registered to the default namespace, it
automatically brings VF NIC back to the default namespace. This will cause
the default_device_exit_net() >> for_each_netdev_safe loop unable to detect
the list end, and hit NULL ptr:

[  231.449420] mana 7870:00:00.0 enP30832s1: Moved VF to namespace with: eth0
[  231.449656] BUG: kernel NULL pointer dereference, address: 0000000000000010
[  231.450246] #PF: supervisor read access in kernel mode
[  231.450579] #PF: error_code(0x0000) - not-present page
[  231.450916] PGD 17b8a8067 P4D 0
[  231.451163] Oops: Oops: 0000 [#1] SMP NOPTI
[  231.451450] CPU: 82 UID: 0 PID: 1394 Comm: kworker/u768:1 Not tainted 6.16.0-rc4+ #3 VOLUNTARY
[  231.452042] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024
[  231.452692] Workqueue: netns cleanup_net
[  231.452947] RIP: 0010:default_device_exit_batch+0x16c/0x3f0
[  231.453326] Code: c0 0c f5 b3 e8 d5 db fe ff 48 85 c0 74 15 48 c7 c2 f8 fd ca b2 be 10 00 00 00 48 8d 7d c0 e8 7b 77 25 00 49 8b 86 28 01 00 00 <48> 8b 50 10 4c 8b 2a 4c 8d 62 f0 49 83 ed 10 4c 39 e0 0f 84 d6 00
[  231.454294] RSP: 0018:ff75fc7c9bf9fd00 EFLAGS: 00010246
[  231.454610] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 61c8864680b583eb
[  231.455094] RDX: ff1fa9f71462d800 RSI: ff75fc7c9bf9fd38 RDI: 0000000030766564
[  231.455686] RBP: ff75fc7c9bf9fd78 R08: 0000000000000000 R09: 0000000000000000
[  231.456126] R10: 0000000000000001 R11: 0000000000000004 R12: ff1fa9f70088e340
[  231.456621] R13: ff1fa9f70088e340 R14: ffffffffb3f50c20 R15: ff1fa9f7103e6340
[  231.457161] FS:  0000000000000000(0000) GS:ff1faa6783a08000(0000) knlGS:0000000000000000
[  231.457707] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  231.458031] CR2: 0000000000000010 CR3: 0000000179ab2006 CR4: 0000000000b73ef0
[  231.458434] Call Trace:
[  231.458600]  <TASK>
[  231.458777]  ops_undo_list+0x100/0x220
[  231.459015]  cleanup_net+0x1b8/0x300
[  231.459285]  process_one_work+0x184/0x340

To fix it, move the ns change to a workqueue, and take rtnl_lock to avoid
changing the netdev list when default_device_exit_net() is using it.

Cc: stable@vger.kernel.org
Fixes: 4c26280 ("hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://patch.msgid.link/1754511711-11188-1-git-send-email-haiyangz@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 14, 2025
syzbot reported the splat below. [0]

When nsim_queue_uninit() is called from nsim_init_netdevsim(),
register_netdevice() has not been called, thus dev->dstats has
not been allocated.

Let's not call dev_dstats_rx_dropped_add() in such a case.

[0]
BUG: unable to handle page fault for address: ffff88809782c020
 PF: supervisor write access in kernel mode
 PF: error_code(0x0002) - not-present page
PGD 1b401067 P4D 1b401067 PUD 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 8476 Comm: syz.1.251 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:local_add arch/x86/include/asm/local.h:33 [inline]
RIP: 0010:u64_stats_add include/linux/u64_stats_sync.h:89 [inline]
RIP: 0010:dev_dstats_rx_dropped_add include/linux/netdevice.h:3027 [inline]
RIP: 0010:nsim_queue_free+0xba/0x120 drivers/net/netdevsim/netdev.c:714
Code: 07 77 6c 4a 8d 3c ed 20 7e f1 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 46 4a 03 1c ed 20 7e f1 8d <4c> 01 63 20 be 00 02 00 00 48 8d 3d 00 00 00 00 e8 61 2f 58 fa 48
RSP: 0018:ffffc900044af150 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: ffff88809782c000 RCX: 00000000000079c3
RDX: 1ffffffff1be2fc7 RSI: ffffffff8c15f380 RDI: ffffffff8df17e38
RBP: ffff88805f59d000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000003 R14: ffff88806ceb3d00 R15: ffffed100dfd308e
FS:  0000000000000000(0000) GS:ffff88809782c000(0063) knlGS:00000000f505db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffff88809782c020 CR3: 000000006fc6a000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nsim_queue_uninit drivers/net/netdevsim/netdev.c:993 [inline]
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1049 [inline]
 nsim_create+0xd0a/0x1260 drivers/net/netdevsim/netdev.c:1101
 __nsim_dev_port_add+0x435/0x7d0 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1494 [inline]
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x5b8/0x860 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x322/0x7c0 net/devlink/dev.c:474
 devlink_nl_reload_doit+0xe31/0x1410 net/devlink/dev.c:584
 genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf708e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f505d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
CR2: ffff88809782c020

Fixes: 2a68a22 ("netdevsim: account dropped packet length in stats on queue free")
Reported-by: syzbot+8aa80c6232008f7b957d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/688bb9ca.a00a0220.26d0e1.0050.GAE@google.com/
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250812162130.4129322-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 14, 2025
Shuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify()
after recent changes from Lion [2]. The problem is: in ets_qdisc_change()
we purge unused DWRR queues; the value of 'q->nbands' is the new one, and
the cleanup should be done with the old one. The problem is here since my
first attempts to fix ets_qdisc_change(), but it surfaced again after the
recent qdisc len accounting fixes. Fix it purging idle DWRR queues before
assigning a new value of 'q->nbands', so that all purge operations find a
consistent configuration:

 - old 'q->nbands' because it's needed by ets_class_find()
 - old 'q->nstrict' because it's needed by ets_class_is_strict()

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary)
 Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021
 RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80
 Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab
 RSP: 0018:ffffba186009f400 EFLAGS: 00010202
 RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004
 RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004
 R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000
 R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000
 FS:  00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
  ets_class_qlen_notify+0x65/0x90 [sch_ets]
  qdisc_tree_reduce_backlog+0x74/0x110
  ets_qdisc_change+0x630/0xa40 [sch_ets]
  __tc_modify_qdisc.constprop.0+0x216/0x7f0
  tc_modify_qdisc+0x7c/0x120
  rtnetlink_rcv_msg+0x145/0x3f0
  netlink_rcv_skb+0x53/0x100
  netlink_unicast+0x245/0x390
  netlink_sendmsg+0x21b/0x470
  ____sys_sendmsg+0x39d/0x3d0
  ___sys_sendmsg+0x9a/0xe0
  __sys_sendmsg+0x7a/0xd0
  do_syscall_64+0x7d/0x160
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 RIP: 0033:0x7f2155114084
 Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
 RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084
 RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003
 RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f
 R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0
 R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0
  </TASK>

 [1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.1639153474.git.dcaratti@redhat.com/
 [2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/

Cc: stable@vger.kernel.org
Fixes: 103406b ("net/sched: Always pass notifications when child class becomes empty")
Fixes: c062f2a ("net/sched: sch_ets: don't remove idle classes from the round-robin list")
Fixes: dcc68b4 ("net: sch_ets: Add a new Qdisc")
Reported-by: Li Shuang <shuali@redhat.com>
Closes: https://issues.redhat.com/browse/RHEL-108026
Reviewed-by: Petr Machata <petrm@nvidia.com>
Co-developed-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/7928ff6d17db47a2ae7cc205c44777b1f1950545.1755016081.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 18, 2025
btrfs_subpage_set_writeback() calls folio_start_writeback() the first time
a folio is written back, and it also clears the PAGECACHE_TAG_TOWRITE tag
even if there are still dirty blocks in the folio. This can break ordering
guarantees, such as those required by btrfs_wait_ordered_extents().

That ordering breakage leads to a real failure. For example, running
generic/464 on a zoned setup will hit the following ASSERT. This happens
because the broken ordering fails to flush existing dirty pages before the
file size is truncated.

  assertion failed: !list_empty(&ordered->list) :: 0, in fs/btrfs/zoned.c:1899
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/zoned.c:1899!
  Oops: invalid opcode: 0000 [#1] SMP NOPTI
  CPU: 2 UID: 0 PID: 1906169 Comm: kworker/u130:2 Kdump: loaded Not tainted 6.16.0-rc6-BTRFS-ZNS+ #554 PREEMPT(voluntary)
  Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.0 02/22/2021
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  RIP: 0010:btrfs_finish_ordered_zoned.cold+0x50/0x52 [btrfs]
  RSP: 0018:ffffc9002efdbd60 EFLAGS: 00010246
  RAX: 000000000000004c RBX: ffff88811923c4e0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffffffff827e38b1 RDI: 00000000ffffffff
  RBP: ffff88810005d000 R08: 00000000ffffdfff R09: ffffffff831051c8
  R10: ffffffff83055220 R11: 0000000000000000 R12: ffff8881c2458c00
  R13: ffff88811923c540 R14: ffff88811923c5e8 R15: ffff8881c1bd9680
  FS:  0000000000000000(0000) GS:ffff88a04acd0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f907c7a918c CR3: 0000000004024000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
   ? srso_return_thunk+0x5/0x5f
   btrfs_finish_ordered_io+0x4a/0x60 [btrfs]
   btrfs_work_helper+0xf9/0x490 [btrfs]
   process_one_work+0x204/0x590
   ? srso_return_thunk+0x5/0x5f
   worker_thread+0x1d6/0x3d0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x118/0x230
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x205/0x260
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

Consider process A calling writepages() with WB_SYNC_NONE. In zoned mode or
for compressed writes, it locks several folios for delalloc and starts
writing them out. Let's call the last locked folio folio X. Suppose the
write range only partially covers folio X, leaving some pages dirty.
Process A calls btrfs_subpage_set_writeback() when building a bio. This
function call clears the TOWRITE tag of folio X, whose size = 8K and
the block size = 4K. It is following state.

   0     4K    8K
   |/////|/////|  (flag: DIRTY, tag: DIRTY)
   <-----> Process A will write this range.

Now suppose process B concurrently calls writepages() with WB_SYNC_ALL. It
calls tag_pages_for_writeback() to tag dirty folios with
PAGECACHE_TAG_TOWRITE. Since folio X is still dirty, it gets tagged. Then,
B collects tagged folios using filemap_get_folios_tag() and must wait for
folio X to be written before returning from writepages().

   0     4K    8K
   |/////|/////|  (flag: DIRTY, tag: DIRTY|TOWRITE)

However, between tagging and collecting, process A may call
btrfs_subpage_set_writeback() and clear folio X's TOWRITE tag.
   0     4K    8K
   |     |/////|  (flag: DIRTY|WRITEBACK, tag: DIRTY)

As a result, process B won't see folio X in its batch, and returns without
waiting for it. This breaks the WB_SYNC_ALL ordering requirement.

Fix this by using btrfs_subpage_set_writeback_keepwrite(), which retains
the TOWRITE tag. We now manually clear the tag only after the folio becomes
clean, via the xas operation.

Fixes: 3470da3 ("btrfs: subpage: introduce helpers for writeback status")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
pull bot pushed a commit that referenced this pull request Aug 19, 2025
An use-after-free issue occurred when __mark_inode_dirty() get the
bdi_writeback that was in the progress of switching.

CPU: 1 PID: 562 Comm: systemd-random- Not tainted 6.6.56-gb4403bd46a8e #1
......
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __mark_inode_dirty+0x124/0x418
lr : __mark_inode_dirty+0x118/0x418
sp : ffffffc08c9dbbc0
........
Call trace:
 __mark_inode_dirty+0x124/0x418
 generic_update_time+0x4c/0x60
 file_modified+0xcc/0xd0
 ext4_buffered_write_iter+0x58/0x124
 ext4_file_write_iter+0x54/0x704
 vfs_write+0x1c0/0x308
 ksys_write+0x74/0x10c
 __arm64_sys_write+0x1c/0x28
 invoke_syscall+0x48/0x114
 el0_svc_common.constprop.0+0xc0/0xe0
 do_el0_svc+0x1c/0x28
 el0_svc+0x40/0xe4
 el0t_64_sync_handler+0x120/0x12c
 el0t_64_sync+0x194/0x198

Root cause is:

systemd-random-seed                         kworker
----------------------------------------------------------------------
___mark_inode_dirty                     inode_switch_wbs_work_fn

  spin_lock(&inode->i_lock);
  inode_attach_wb
  locked_inode_to_wb_and_lock_list
     get inode->i_wb
     spin_unlock(&inode->i_lock);
     spin_lock(&wb->list_lock)
  spin_lock(&inode->i_lock)
  inode_io_list_move_locked
  spin_unlock(&wb->list_lock)
  spin_unlock(&inode->i_lock)
                                    spin_lock(&old_wb->list_lock)
                                      inode_do_switch_wbs
                                        spin_lock(&inode->i_lock)
                                        inode->i_wb = new_wb
                                        spin_unlock(&inode->i_lock)
                                    spin_unlock(&old_wb->list_lock)
                                    wb_put_many(old_wb, nr_switched)
                                      cgwb_release
                                      old wb released
  wb_wakeup_delayed() accesses wb,
  then trigger the use-after-free
  issue

Fix this race condition by holding inode spinlock until
wb_wakeup_delayed() finished.

Signed-off-by: Jiufei Xue <jiufei.xue@samsung.com>
Link: https://lore.kernel.org/20250728100715.3863241-1-jiufei.xue@samsung.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 21, 2025
…dlock

When a user creates a dualpi2 qdisc it automatically sets a timer. This
timer will run constantly and update the qdisc's probability field.
The issue is that the timer acquires the qdisc root lock and runs in
hardirq. The qdisc root lock is also acquired in dev.c whenever a packet
arrives for this qdisc. Since the dualpi2 timer callback runs in hardirq,
it may interrupt the packet processing running in softirq. If that happens
and it runs on the same CPU, it will acquire the same lock and cause a
deadlock. The following splat shows up when running a kernel compiled with
lock debugging:

[  +0.000224] WARNING: inconsistent lock state
[  +0.000224] 6.16.0+ #10 Not tainted
[  +0.000169] --------------------------------
[  +0.000029] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[  +0.000000] ping/156 [HC0[0]:SC0[2]:HE1:SE0] takes:
[  +0.000000] ffff897841242110 (&sch->root_lock_key){?.-.}-{3:3}, at: __dev_queue_xmit+0x86d/0x1140
[  +0.000000] {IN-HARDIRQ-W} state was registered at:
[  +0.000000]   lock_acquire.part.0+0xb6/0x220
[  +0.000000]   _raw_spin_lock+0x31/0x80
[  +0.000000]   dualpi2_timer+0x6f/0x270
[  +0.000000]   __hrtimer_run_queues+0x1c5/0x360
[  +0.000000]   hrtimer_interrupt+0x115/0x260
[  +0.000000]   __sysvec_apic_timer_interrupt+0x6d/0x1a0
[  +0.000000]   sysvec_apic_timer_interrupt+0x6e/0x80
[  +0.000000]   asm_sysvec_apic_timer_interrupt+0x1a/0x20
[  +0.000000]   pv_native_safe_halt+0xf/0x20
[  +0.000000]   default_idle+0x9/0x10
[  +0.000000]   default_idle_call+0x7e/0x1e0
[  +0.000000]   do_idle+0x1e8/0x250
[  +0.000000]   cpu_startup_entry+0x29/0x30
[  +0.000000]   rest_init+0x151/0x160
[  +0.000000]   start_kernel+0x6f3/0x700
[  +0.000000]   x86_64_start_reservations+0x24/0x30
[  +0.000000]   x86_64_start_kernel+0xc8/0xd0
[  +0.000000]   common_startup_64+0x13e/0x148
[  +0.000000] irq event stamp: 6884
[  +0.000000] hardirqs last  enabled at (6883): [<ffffffffa75700b3>] neigh_resolve_output+0x223/0x270
[  +0.000000] hardirqs last disabled at (6882): [<ffffffffa7570078>] neigh_resolve_output+0x1e8/0x270
[  +0.000000] softirqs last  enabled at (6880): [<ffffffffa757006b>] neigh_resolve_output+0x1db/0x270
[  +0.000000] softirqs last disabled at (6884): [<ffffffffa755b533>] __dev_queue_xmit+0x73/0x1140
[  +0.000000]
              other info that might help us debug this:
[  +0.000000]  Possible unsafe locking scenario:

[  +0.000000]        CPU0
[  +0.000000]        ----
[  +0.000000]   lock(&sch->root_lock_key);
[  +0.000000]   <Interrupt>
[  +0.000000]     lock(&sch->root_lock_key);
[  +0.000000]
               *** DEADLOCK ***

[  +0.000000] 4 locks held by ping/156:
[  +0.000000]  #0: ffff897842332e08 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x41e/0xf40
[  +0.000000]  #1: ffffffffa816f880 (rcu_read_lock){....}-{1:3}, at: ip_output+0x2c/0x190
[  +0.000000]  #2: ffffffffa816f880 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0xad/0x950
[  +0.000000]  #3: ffffffffa816f840 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x73/0x1140

I am able to reproduce it consistently when running the following:

tc qdisc add dev lo handle 1: root dualpi2
ping -f 127.0.0.1

To fix it, make the timer run in softirq.

Fixes: 320d031 ("sched: Struct definition and parsing of dualpi2 qdisc")
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250815135317.664993-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 21, 2025
BPF CI testing report a UAF issue:

  [   16.446633] BUG: kernel NULL pointer dereference, address: 000000000000003  0
  [   16.447134] #PF: supervisor read access in kernel mod  e
  [   16.447516] #PF: error_code(0x0000) - not-present pag  e
  [   16.447878] PGD 0 P4D   0
  [   16.448063] Oops: Oops: 0000 [#1] PREEMPT SMP NOPT  I
  [   16.448409] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Tainted: G           OE      6.13.0-rc3-g89e8a75fda73-dirty #4  2
  [   16.449124] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODUL  E
  [   16.449502] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/201  4
  [   16.450201] Workqueue: smc_hs_wq smc_listen_wor  k
  [   16.450531] RIP: 0010:smc_listen_work+0xc02/0x159  0
  [   16.452158] RSP: 0018:ffffb5ab40053d98 EFLAGS: 0001024  6
  [   16.452526] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 000000000000030  0
  [   16.452994] RDX: 0000000000000280 RSI: 00003513840053f0 RDI: 000000000000000  0
  [   16.453492] RBP: ffffa097808e3800 R08: ffffa09782dba1e0 R09: 000000000000000  5
  [   16.453987] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa0978274640  0
  [   16.454497] R13: 0000000000000000 R14: 0000000000000000 R15: ffffa09782d4092  0
  [   16.454996] FS:  0000000000000000(0000) GS:ffffa097bbc00000(0000) knlGS:000000000000000  0
  [   16.455557] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003  3
  [   16.455961] CR2: 0000000000000030 CR3: 0000000102788004 CR4: 0000000000770ef  0
  [   16.456459] PKRU: 5555555  4
  [   16.456654] Call Trace  :
  [   16.456832]  <TASK  >
  [   16.456989]  ? __die+0x23/0x7  0
  [   16.457215]  ? page_fault_oops+0x180/0x4c  0
  [   16.457508]  ? __lock_acquire+0x3e6/0x249  0
  [   16.457801]  ? exc_page_fault+0x68/0x20  0
  [   16.458080]  ? asm_exc_page_fault+0x26/0x3  0
  [   16.458389]  ? smc_listen_work+0xc02/0x159  0
  [   16.458689]  ? smc_listen_work+0xc02/0x159  0
  [   16.458987]  ? lock_is_held_type+0x8f/0x10  0
  [   16.459284]  process_one_work+0x1ea/0x6d  0
  [   16.459570]  worker_thread+0x1c3/0x38  0
  [   16.459839]  ? __pfx_worker_thread+0x10/0x1  0
  [   16.460144]  kthread+0xe0/0x11  0
  [   16.460372]  ? __pfx_kthread+0x10/0x1  0
  [   16.460640]  ret_from_fork+0x31/0x5  0
  [   16.460896]  ? __pfx_kthread+0x10/0x1  0
  [   16.461166]  ret_from_fork_asm+0x1a/0x3  0
  [   16.461453]  </TASK  >
  [   16.461616] Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod(OE)  ]
  [   16.462134] CR2: 000000000000003  0
  [   16.462380] ---[ end trace 0000000000000000 ]---
  [   16.462710] RIP: 0010:smc_listen_work+0xc02/0x1590

The direct cause of this issue is that after smc_listen_out_connected(),
newclcsock->sk may be NULL since it will releases the smcsk. Therefore,
if the application closes the socket immediately after accept,
newclcsock->sk can be NULL. A possible execution order could be as
follows:

smc_listen_work                                 | userspace
-----------------------------------------------------------------
lock_sock(sk)                                   |
smc_listen_out_connected()                      |
| \- smc_listen_out                             |
|    | \- release_sock                          |
     | |- sk->sk_data_ready()                   |
                                                | fd = accept();
                                                | close(fd);
                                                |  \- socket->sk = NULL;
/* newclcsock->sk is NULL now */
SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk))

Since smc_listen_out_connected() will not fail, simply swapping the order
of the code can easily fix this issue.

Fixes: 3b2dec2 ("net/smc: restructure client and server code in af_smc")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Link: https://patch.msgid.link/20250818054618.41615-1-alibuda@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 21, 2025
Receiving HSR frame with insufficient space to hold HSR tag in the skb
can result in a crash (kernel BUG):

[   45.390915] skbuff: skb_under_panic: text:ffffffff86f32cac len:26 put:14 head:ffff888042418000 data:ffff888042417ff4 tail:0xe end:0x180 dev:bridge_slave_1
[   45.392559] ------------[ cut here ]------------
[   45.392912] kernel BUG at net/core/skbuff.c:211!
[   45.393276] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[   45.393809] CPU: 1 UID: 0 PID: 2496 Comm: reproducer Not tainted 6.15.0 #12 PREEMPT(undef)
[   45.394433] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   45.395273] RIP: 0010:skb_panic+0x15b/0x1d0

<snip registers, remove unreliable trace>

[   45.402911] Call Trace:
[   45.403105]  <IRQ>
[   45.404470]  skb_push+0xcd/0xf0
[   45.404726]  br_dev_queue_push_xmit+0x7c/0x6c0
[   45.406513]  br_forward_finish+0x128/0x260
[   45.408483]  __br_forward+0x42d/0x590
[   45.409464]  maybe_deliver+0x2eb/0x420
[   45.409763]  br_flood+0x174/0x4a0
[   45.410030]  br_handle_frame_finish+0xc7c/0x1bc0
[   45.411618]  br_handle_frame+0xac3/0x1230
[   45.413674]  __netif_receive_skb_core.constprop.0+0x808/0x3df0
[   45.422966]  __netif_receive_skb_one_core+0xb4/0x1f0
[   45.424478]  __netif_receive_skb+0x22/0x170
[   45.424806]  process_backlog+0x242/0x6d0
[   45.425116]  __napi_poll+0xbb/0x630
[   45.425394]  net_rx_action+0x4d1/0xcc0
[   45.427613]  handle_softirqs+0x1a4/0x580
[   45.427926]  do_softirq+0x74/0x90
[   45.428196]  </IRQ>

This issue was found by syzkaller.

The panic happens in br_dev_queue_push_xmit() once it receives a
corrupted skb with ETH header already pushed in linear data. When it
attempts the skb_push() call, there's not enough headroom and
skb_push() panics.

The corrupted skb is put on the queue by HSR layer, which makes a
sequence of unintended transformations when it receives a specific
corrupted HSR frame (with incomplete TAG).

Fix it by dropping and consuming frames that are not long enough to
contain both ethernet and hsr headers.

Alternative fix would be to check for enough headroom before skb_push()
in br_dev_queue_push_xmit().

In the reproducer, this is injected via AF_PACKET, but I don't easily
see why it couldn't be sent over the wire from adjacent network.

Further Details:

In the reproducer, the following network interface chain is set up:

┌────────────────┐   ┌────────────────┐
│ veth0_to_hsr   ├───┤  hsr_slave0    ┼───┐
└────────────────┘   └────────────────┘   │
                                          │ ┌──────┐
                                          ├─┤ hsr0 ├───┐
                                          │ └──────┘   │
┌────────────────┐   ┌────────────────┐   │            │┌────────┐
│ veth1_to_hsr   ┼───┤  hsr_slave1    ├───┘            └┤        │
└────────────────┘   └────────────────┘                ┌┼ bridge │
                                                       ││        │
                                                       │└────────┘
                                                       │
                                        ┌───────┐      │
                                        │  ...  ├──────┘
                                        └───────┘

To trigger the events leading up to crash, reproducer sends a corrupted
HSR frame with incomplete TAG, via AF_PACKET socket on 'veth0_to_hsr'.

The first HSR-layer function to process this frame is
hsr_handle_frame(). It and then checks if the
protocol is ETH_P_PRP or ETH_P_HSR. If it is, it calls
skb_set_network_header(skb, ETH_HLEN + HSR_HLEN), without checking that
the skb is long enough. For the crashing frame it is not, and hence the
skb->network_header and skb->mac_len fields are set incorrectly,
pointing after the end of the linear buffer.

I will call this a BUG#1 and it is what is addressed by this patch. In
the crashing scenario before the fix, the skb continues to go down the
hsr path as follows.

hsr_handle_frame() then calls this sequence
hsr_forward_skb()
  fill_frame_info()
    hsr->proto_ops->fill_frame_info()
      hsr_fill_frame_info()

hsr_fill_frame_info() contains a check that intends to check whether the
skb actually contains the HSR header. But the check relies on the
skb->mac_len field which was erroneously setup due to BUG#1, so the
check passes and the execution continues  back in the hsr_forward_skb():

hsr_forward_skb()
  hsr_forward_do()
    hsr->proto_ops->get_untagged_frame()
      hsr_get_untagged_frame()
        create_stripped_skb_hsr()

In create_stripped_skb_hsr(), a copy of the skb is created and is
further corrupted by operation that attempts to strip the HSR tag in a
call to __pskb_copy().

The skb enters create_stripped_skb_hsr() with ethernet header pushed in
linear buffer. The skb_pull(skb_in, HSR_HLEN) thus pulls 6 bytes of
ethernet header into the headroom, creating skb_in with a headroom of
size 8. The subsequent __pskb_copy() then creates an skb with headroom
of just 2 and skb->len of just 12, this is how it looks after the copy:

gdb) p skb->len
$10 = 12
(gdb) p skb->data
$11 = (unsigned char *) 0xffff888041e45382 "\252\252\252\252\252!\210\373",
(gdb) p skb->head
$12 = (unsigned char *) 0xffff888041e45380 ""

It seems create_stripped_skb_hsr() assumes that ETH header is pulled
in the headroom when it's entered, because it just pulls HSR header on
top. But that is not the case in our code-path and we end up with the
corrupted skb instead. I will call this BUG#2

*I got confused here because it seems that under no conditions can
create_stripped_skb_hsr() work well, the assumption it makes is not true
during the processing of hsr frames - since the skb_push() in
hsr_handle_frame to skb_pull in hsr_deliver_master(). I wonder whether I
missed something here.*

Next, the execution arrives in hsr_deliver_master(). It calls
skb_pull(ETH_HLEN), which just returns NULL - the SKB does not have
enough space for the pull (as it only has 12 bytes in total at this
point).

*The skb_pull() here further suggests that ethernet header is meant
to be pushed through the whole hsr processing and
create_stripped_skb_hsr() should pull it before doing the HSR header
pull.*

hsr_deliver_master() then puts the corrupted skb on the queue, it is
then picked up from there by bridge frame handling layer and finally
lands in br_dev_queue_push_xmit where it panics.

Cc: stable@kernel.org
Fixes: 48b491a ("net: hsr: fix mac_len checks")
Reported-by: syzbot+a81f2759d022496b40ab@syzkaller.appspotmail.com
Signed-off-by: Jakub Acs <acsjakub@amazon.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250819082842.94378-1-acsjakub@amazon.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 22, 2025
Commit 3c7ac40 ("scsi: ufs: core: Delegate the interrupt service
routine to a threaded IRQ handler") introduced an IRQ lock inversion
issue. Fix this lock inversion by changing the spin_lock_irq() calls into
spin_lock_irqsave() calls in code that can be called either from
interrupt context or from thread context. This patch fixes the following
lockdep complaint:

WARNING: possible irq lock inversion dependency detected
6.12.30-android16-5-maybe-dirty-4k #1 Tainted: G        W  OE
--------------------------------------------------------
kworker/u28:0/12 just changed the state of lock:
ffffff881e29dd60 (&hba->clk_gating.lock){-...}-{2:2}, at: ufshcd_release_scsi_cmd+0x60/0x110
but this lock took another, HARDIRQ-unsafe lock in the past:
 (shost->host_lock){+.+.}-{2:2}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(shost->host_lock);
                               local_irq_disable();
                               lock(&hba->clk_gating.lock);
                               lock(shost->host_lock);
  <Interrupt>
    lock(&hba->clk_gating.lock);

 *** DEADLOCK ***

4 locks held by kworker/u28:0/12:
 #0: ffffff8800ac6158 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x1bc/0x65c
 #1: ffffffc085c93d70 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1e4/0x65c
 #2: ffffff881e29c0e0 (&shost->scan_mutex){+.+.}-{3:3}, at: __scsi_add_device+0x74/0x120
 #3: ffffff881960ea00 (&hwq->cq_lock){-...}-{2:2}, at: ufshcd_mcq_poll_cqe_lock+0x28/0x104

the shortest dependencies between 2nd lock and 1st lock:
 -> (shost->host_lock){+.+.}-{2:2} {
    HARDIRQ-ON-W at:
                      lock_acquire+0x134/0x2b4
                      _raw_spin_lock+0x48/0x64
                      ufshcd_sl_intr+0x4c/0xa08
                      ufshcd_threaded_intr+0x70/0x12c
                      irq_thread_fn+0x48/0xa8
                      irq_thread+0x130/0x1ec
                      kthread+0x110/0x134
                      ret_from_fork+0x10/0x20
    SOFTIRQ-ON-W at:
                      lock_acquire+0x134/0x2b4
                      _raw_spin_lock+0x48/0x64
                      ufshcd_sl_intr+0x4c/0xa08
                      ufshcd_threaded_intr+0x70/0x12c
                      irq_thread_fn+0x48/0xa8
                      irq_thread+0x130/0x1ec
                      kthread+0x110/0x134
                      ret_from_fork+0x10/0x20
    INITIAL USE at:
                     lock_acquire+0x134/0x2b4
                     _raw_spin_lock+0x48/0x64
                     ufshcd_sl_intr+0x4c/0xa08
                     ufshcd_threaded_intr+0x70/0x12c
                     irq_thread_fn+0x48/0xa8
                     irq_thread+0x130/0x1ec
                     kthread+0x110/0x134
                     ret_from_fork+0x10/0x20
  }
  ... key      at: [<ffffffc085ba1a98>] scsi_host_alloc.__key+0x0/0x10
  ... acquired at:
   _raw_spin_lock_irqsave+0x5c/0x80
   __ufshcd_release+0x78/0x118
   ufshcd_send_uic_cmd+0xe4/0x118
   ufshcd_dme_set_attr+0x88/0x1c8
   ufs_google_phy_initialization+0x68/0x418 [ufs]
   ufs_google_link_startup_notify+0x78/0x27c [ufs]
   ufshcd_link_startup+0x84/0x720
   ufshcd_init+0xf3c/0x1330
   ufshcd_pltfrm_init+0x728/0x7d8
   ufs_google_probe+0x30/0x84 [ufs]
   platform_probe+0xa0/0xe0
   really_probe+0x114/0x454
   __driver_probe_device+0xa4/0x160
   driver_probe_device+0x44/0x23c
   __driver_attach_async_helper+0x60/0xd4
   async_run_entry_fn+0x4c/0x17c
   process_one_work+0x26c/0x65c
   worker_thread+0x33c/0x498
   kthread+0x110/0x134
   ret_from_fork+0x10/0x20

-> (&hba->clk_gating.lock){-...}-{2:2} {
   IN-HARDIRQ-W at:
                    lock_acquire+0x134/0x2b4
                    _raw_spin_lock_irqsave+0x5c/0x80
                    ufshcd_release_scsi_cmd+0x60/0x110
                    ufshcd_compl_one_cqe+0x2c0/0x3f4
                    ufshcd_mcq_poll_cqe_lock+0xb0/0x104
                    ufs_google_mcq_intr+0x80/0xa0 [ufs]
                    __handle_irq_event_percpu+0x104/0x32c
                    handle_irq_event+0x40/0x9c
                    handle_fasteoi_irq+0x170/0x2e8
                    generic_handle_domain_irq+0x58/0x80
                    gic_handle_irq+0x48/0x104
                    call_on_irq_stack+0x3c/0x50
                    do_interrupt_handler+0x7c/0xd8
                    el1_interrupt+0x34/0x58
                    el1h_64_irq_handler+0x18/0x24
                    el1h_64_irq+0x68/0x6c
                    _raw_spin_unlock_irqrestore+0x3c/0x6c
                    debug_object_assert_init+0x16c/0x21c
                    __mod_timer+0x4c/0x48c
                    schedule_timeout+0xd4/0x16c
                    io_schedule_timeout+0x48/0x70
                    do_wait_for_common+0x100/0x194
                    wait_for_completion_io_timeout+0x48/0x6c
                    blk_execute_rq+0x124/0x17c
                    scsi_execute_cmd+0x18c/0x3f8
                    scsi_probe_and_add_lun+0x204/0xd74
                    __scsi_add_device+0xbc/0x120
                    ufshcd_async_scan+0x80/0x3c0
                    async_run_entry_fn+0x4c/0x17c
                    process_one_work+0x26c/0x65c
                    worker_thread+0x33c/0x498
                    kthread+0x110/0x134
                    ret_from_fork+0x10/0x20
   INITIAL USE at:
                   lock_acquire+0x134/0x2b4
                   _raw_spin_lock_irqsave+0x5c/0x80
                   ufshcd_hold+0x34/0x14c
                   ufshcd_send_uic_cmd+0x28/0x118
                   ufshcd_dme_set_attr+0x88/0x1c8
                   ufs_google_phy_initialization+0x68/0x418 [ufs]
                   ufs_google_link_startup_notify+0x78/0x27c [ufs]
                   ufshcd_link_startup+0x84/0x720
                   ufshcd_init+0xf3c/0x1330
                   ufshcd_pltfrm_init+0x728/0x7d8
                   ufs_google_probe+0x30/0x84 [ufs]
                   platform_probe+0xa0/0xe0
                   really_probe+0x114/0x454
                   __driver_probe_device+0xa4/0x160
                   driver_probe_device+0x44/0x23c
                   __driver_attach_async_helper+0x60/0xd4
                   async_run_entry_fn+0x4c/0x17c
                   process_one_work+0x26c/0x65c
                   worker_thread+0x33c/0x498
                   kthread+0x110/0x134
                   ret_from_fork+0x10/0x20
 }
 ... key      at: [<ffffffc085ba6fe8>] ufshcd_init.__key+0x0/0x10
 ... acquired at:
   mark_lock+0x1c4/0x224
   __lock_acquire+0x438/0x2e1c
   lock_acquire+0x134/0x2b4
   _raw_spin_lock_irqsave+0x5c/0x80
   ufshcd_release_scsi_cmd+0x60/0x110
   ufshcd_compl_one_cqe+0x2c0/0x3f4
   ufshcd_mcq_poll_cqe_lock+0xb0/0x104
   ufs_google_mcq_intr+0x80/0xa0 [ufs]
   __handle_irq_event_percpu+0x104/0x32c
   handle_irq_event+0x40/0x9c
   handle_fasteoi_irq+0x170/0x2e8
   generic_handle_domain_irq+0x58/0x80
   gic_handle_irq+0x48/0x104
   call_on_irq_stack+0x3c/0x50
   do_interrupt_handler+0x7c/0xd8
   el1_interrupt+0x34/0x58
   el1h_64_irq_handler+0x18/0x24
   el1h_64_irq+0x68/0x6c
   _raw_spin_unlock_irqrestore+0x3c/0x6c
   debug_object_assert_init+0x16c/0x21c
   __mod_timer+0x4c/0x48c
   schedule_timeout+0xd4/0x16c
   io_schedule_timeout+0x48/0x70
   do_wait_for_common+0x100/0x194
   wait_for_completion_io_timeout+0x48/0x6c
   blk_execute_rq+0x124/0x17c
   scsi_execute_cmd+0x18c/0x3f8
   scsi_probe_and_add_lun+0x204/0xd74
   __scsi_add_device+0xbc/0x120
   ufshcd_async_scan+0x80/0x3c0
   async_run_entry_fn+0x4c/0x17c
   process_one_work+0x26c/0x65c
   worker_thread+0x33c/0x498
   kthread+0x110/0x134
   ret_from_fork+0x10/0x20

stack backtrace:
CPU: 6 UID: 0 PID: 12 Comm: kworker/u28:0 Tainted: G        W  OE      6.12.30-android16-5-maybe-dirty-4k #1 ccd4020fe444bdf629efc3b86df6be920b8df7d0
Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Spacecraft board based on MALIBU (DT)
Workqueue: async async_run_entry_fn
Call trace:
 dump_backtrace+0xfc/0x17c
 show_stack+0x18/0x28
 dump_stack_lvl+0x40/0xa0
 dump_stack+0x18/0x24
 print_irq_inversion_bug+0x2fc/0x304
 mark_lock_irq+0x388/0x4fc
 mark_lock+0x1c4/0x224
 __lock_acquire+0x438/0x2e1c
 lock_acquire+0x134/0x2b4
 _raw_spin_lock_irqsave+0x5c/0x80
 ufshcd_release_scsi_cmd+0x60/0x110
 ufshcd_compl_one_cqe+0x2c0/0x3f4
 ufshcd_mcq_poll_cqe_lock+0xb0/0x104
 ufs_google_mcq_intr+0x80/0xa0 [ufs dd6f385554e109da094ab91d5f7be18625a2222a]
 __handle_irq_event_percpu+0x104/0x32c
 handle_irq_event+0x40/0x9c
 handle_fasteoi_irq+0x170/0x2e8
 generic_handle_domain_irq+0x58/0x80
 gic_handle_irq+0x48/0x104
 call_on_irq_stack+0x3c/0x50
 do_interrupt_handler+0x7c/0xd8
 el1_interrupt+0x34/0x58
 el1h_64_irq_handler+0x18/0x24
 el1h_64_irq+0x68/0x6c
 _raw_spin_unlock_irqrestore+0x3c/0x6c
 debug_object_assert_init+0x16c/0x21c
 __mod_timer+0x4c/0x48c
 schedule_timeout+0xd4/0x16c
 io_schedule_timeout+0x48/0x70
 do_wait_for_common+0x100/0x194
 wait_for_completion_io_timeout+0x48/0x6c
 blk_execute_rq+0x124/0x17c
 scsi_execute_cmd+0x18c/0x3f8
 scsi_probe_and_add_lun+0x204/0xd74
 __scsi_add_device+0xbc/0x120
 ufshcd_async_scan+0x80/0x3c0
 async_run_entry_fn+0x4c/0x17c
 process_one_work+0x26c/0x65c
 worker_thread+0x33c/0x498
 kthread+0x110/0x134
 ret_from_fork+0x10/0x20

Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: André Draszik <andre.draszik@linaro.org>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Fixes: 3c7ac40 ("scsi: ufs: core: Delegate the interrupt service routine to a threaded IRQ handler")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20250815155842.472867-2-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
pull bot pushed a commit that referenced this pull request Aug 22, 2025
The mm/debug_vm_pagetable test allocates manually page table entries for
the tests it runs, using also its manually allocated mm_struct.  That in
itself is ok, but when it exits, at destroy_args() it fails to clear those
entries with the *_clear functions.

The problem is that leaves stale entries.  If another process allocates an
mm_struct with a pgd at the same address, it may end up running into the
stale entry.  This is happening in practice on a debug kernel with
CONFIG_DEBUG_VM_PGTABLE=y, for example this is the output with some extra
debugging I added (it prints a warning trace if pgtables_bytes goes
negative, in addition to the warning at check_mm() function):

[    2.539353] debug_vm_pgtable: [get_random_vaddr         ]: random_vaddr is 0x7ea247140000
[    2.539366] kmem_cache info
[    2.539374] kmem_cachep 0x000000002ce82385 - freelist 0x0000000000000000 - offset 0x508
[    2.539447] debug_vm_pgtable: [init_args                ]: args->mm is 0x000000002267cc9e
(...)
[    2.552800] WARNING: CPU: 5 PID: 116 at include/linux/mm.h:2841 free_pud_range+0x8bc/0x8d0
[    2.552816] Modules linked in:
[    2.552843] CPU: 5 UID: 0 PID: 116 Comm: modprobe Not tainted 6.12.0-105.debug_vm2.el10.ppc64le+debug #1 VOLUNTARY
[    2.552859] Hardware name: IBM,9009-41A POWER9 (architected) 0x4e0202 0xf000005 of:IBM,FW910.00 (VL910_062) hv:phyp pSeries
[    2.552872] NIP:  c0000000007eef3c LR: c0000000007eef30 CTR: c0000000003d8c90
[    2.552885] REGS: c0000000622e73b0 TRAP: 0700   Not tainted  (6.12.0-105.debug_vm2.el10.ppc64le+debug)
[    2.552899] MSR:  800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 24002822  XER: 0000000a
[    2.552954] CFAR: c0000000008f03f0 IRQMASK: 0
[    2.552954] GPR00: c0000000007eef30 c0000000622e7650 c000000002b1ac00 0000000000000001
[    2.552954] GPR04: 0000000000000008 0000000000000000 c0000000007eef30 ffffffffffffffff
[    2.552954] GPR08: 00000000ffff00f5 0000000000000001 0000000000000048 0000000000004000
[    2.552954] GPR12: 00000003fa440000 c000000017ffa300 c0000000051d9f80 ffffffffffffffdb
[    2.552954] GPR16: 0000000000000000 0000000000000008 000000000000000a 60000000000000e0
[    2.552954] GPR20: 4080000000000000 c0000000113af038 00007fffcf130000 0000700000000000
[    2.552954] GPR24: c000000062a6a000 0000000000000001 8000000062a68000 0000000000000001
[    2.552954] GPR28: 000000000000000a c000000062ebc600 0000000000002000 c000000062ebc760
[    2.553170] NIP [c0000000007eef3c] free_pud_range+0x8bc/0x8d0
[    2.553185] LR [c0000000007eef30] free_pud_range+0x8b0/0x8d0
[    2.553199] Call Trace:
[    2.553207] [c0000000622e7650] [c0000000007eef30] free_pud_range+0x8b0/0x8d0 (unreliable)
[    2.553229] [c0000000622e7750] [c0000000007f40b4] free_pgd_range+0x284/0x3b0
[    2.553248] [c0000000622e7800] [c0000000007f4630] free_pgtables+0x450/0x570
[    2.553274] [c0000000622e78e0] [c0000000008161c0] exit_mmap+0x250/0x650
[    2.553292] [c0000000622e7a30] [c0000000001b95b8] __mmput+0x98/0x290
[    2.558344] [c0000000622e7a80] [c0000000001d1018] exit_mm+0x118/0x1b0
[    2.558361] [c0000000622e7ac0] [c0000000001d141c] do_exit+0x2ec/0x870
[    2.558376] [c0000000622e7b60] [c0000000001d1ca8] do_group_exit+0x88/0x150
[    2.558391] [c0000000622e7bb0] [c0000000001d1db8] sys_exit_group+0x48/0x50
[    2.558407] [c0000000622e7be0] [c00000000003d810] system_call_exception+0x1e0/0x4c0
[    2.558423] [c0000000622e7e50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
(...)
[    2.558892] ---[ end trace 0000000000000000 ]---
[    2.559022] BUG: Bad rss-counter state mm:000000002267cc9e type:MM_ANONPAGES val:1
[    2.559037] BUG: non-zero pgtables_bytes on freeing mm: -6144

Here the modprobe process ended up with an allocated mm_struct from the
mm_struct slab that was used before by the debug_vm_pgtable test.  That is
not a problem, since the mm_struct is initialized again etc., however, if
it ends up using the same pgd table, it bumps into the old stale entry
when clearing/freeing the page table entries, so it tries to free an entry
already gone (that one which was allocated by the debug_vm_pgtable test),
which also explains the negative pgtables_bytes since it's accounting for
not allocated entries in the current process.

As far as I looked pgd_{alloc,free} etc.  does not clear entries, and
clearing of the entries is explicitly done in the free_pgtables->
free_pgd_range->free_p4d_range->free_pud_range->free_pmd_range->
free_pte_range path.  However, the debug_vm_pgtable test does not call
free_pgtables, since it allocates mm_struct and entries manually for its
test and eg.  not goes through page faults.  So it also should clear
manually the entries before exit at destroy_args().

This problem was noticed on a reboot X number of times test being done on
a powerpc host, with a debug kernel with CONFIG_DEBUG_VM_PGTABLE enabled. 
Depends on the system, but on a 100 times reboot loop the problem could
manifest once or twice, if a process ends up getting the right mm->pgd
entry with the stale entries used by mm/debug_vm_pagetable.  After using
this patch, I couldn't reproduce/experience the problems anymore.  I was
able to reproduce the problem as well on latest upstream kernel (6.16).

I also modified destroy_args() to use mmput() instead of mmdrop(), there
is no reason to hold mm_users reference and not release the mm_struct
entirely, and in the output above with my debugging prints I already had
patched it to use mmput, it did not fix the problem, but helped in the
debugging as well.

Link: https://lkml.kernel.org/r/20250731214051.4115182-1-herton@redhat.com
Fixes: 3c9b84f ("mm/debug_vm_pgtable: introduce struct pgtable_debug_args")
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Aug 29, 2025
syzbot reported the splat below. [0]

When atmtcp_v_open() or atmtcp_v_close() is called via connect()
or close(), atmtcp_send_control() is called to send an in-kernel
special message.

The message has ATMTCP_HDR_MAGIC in atmtcp_control.hdr.length.
Also, a pointer of struct atm_vcc is set to atmtcp_control.vcc.

The notable thing is struct atmtcp_control is uAPI but has a
space for an in-kernel pointer.

  struct atmtcp_control {
  	struct atmtcp_hdr hdr;	/* must be first */
  ...
  	atm_kptr_t vcc;		/* both directions */
  ...
  } __ATM_API_ALIGN;

  typedef struct { unsigned char _[8]; } __ATM_API_ALIGN atm_kptr_t;

The special message is processed in atmtcp_recv_control() called
from atmtcp_c_send().

atmtcp_c_send() is vcc->dev->ops->send() and called from 2 paths:

  1. .ndo_start_xmit() (vcc->send() == atm_send_aal0())
  2. vcc_sendmsg()

The problem is sendmsg() does not validate the message length and
userspace can abuse atmtcp_recv_control() to overwrite any kptr
by atmtcp_control.

Let's add a new ->pre_send() hook to validate messages from sendmsg().

[0]:
Oops: general protection fault, probably for non-canonical address 0xdffffc00200000ab: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000100000558-0x000000010000055f]
CPU: 0 UID: 0 PID: 5865 Comm: syz-executor331 Not tainted 6.17.0-rc1-syzkaller-00215-gbab3ce404553 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:atmtcp_recv_control drivers/atm/atmtcp.c:93 [inline]
RIP: 0010:atmtcp_c_send+0x1da/0x950 drivers/atm/atmtcp.c:297
Code: 4d 8d 75 1a 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 15 06 00 00 41 0f b7 1e 4d 8d b7 60 05 00 00 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 13 06 00 00 66 41 89 1e 4d 8d 75 1c 4c
RSP: 0018:ffffc90003f5f810 EFLAGS: 00010203
RAX: 00000000200000ab RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802a510000 RSI: 00000000ffffffff RDI: ffff888030a6068c
RBP: ffff88802699fb40 R08: ffff888030a606eb R09: 1ffff1100614c0dd
R10: dffffc0000000000 R11: ffffffff8718fc40 R12: dffffc0000000000
R13: ffff888030a60680 R14: 000000010000055f R15: 00000000ffffffff
FS:  00007f8d7e9236c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ad50 CR3: 0000000075bde000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 vcc_sendmsg+0xa10/0xc60 net/atm/common.c:645
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8d7e96a4a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8d7e923198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8d7e9f4308 RCX: 00007f8d7e96a4a9
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000005
RBP: 00007f8d7e9f4300 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 65732f636f72702f R11: 0000000000000246 R12: 00007f8d7e9c10ac
R13: 00007f8d7e9231a0 R14: 0000200000000200 R15: 0000200000000250
 </TASK>
Modules linked in:

Fixes: 1da177e ("Linux-2.6.12-rc2")
Reported-by: syzbot+1741b56d54536f4ec349@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68a6767c.050a0220.3d78fd.0011.GAE@google.com/
Tested-by: syzbot+1741b56d54536f4ec349@syzkaller.appspotmail.com
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250821021901.2814721-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Aug 29, 2025
These iterations require the read lock, otherwise RCU
lockdep will splat:

=============================
WARNING: suspicious RCU usage
6.17.0-rc3-00014-g31419c045d64 #6 Tainted: G           O
-----------------------------
drivers/base/power/main.c:1333 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
5 locks held by rtcwake/547:
 #0: 00000000643ab418 (sb_writers#6){.+.+}-{0:0}, at: file_start_write+0x2b/0x3a
 #1: 0000000067a0ca88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x181/0x24b
 #2: 00000000631eac40 (kn->active#3){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x191/0x24b
 #3: 00000000609a1308 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0xaf/0x30b
 #4: 0000000060c0fdb0 (device_links_srcu){.+.+}-{0:0}, at: device_links_read_lock+0x75/0x98

stack backtrace:
CPU: 0 UID: 0 PID: 547 Comm: rtcwake Tainted: G           O        6.17.0-rc3-00014-g31419c045d64 #6 VOLUNTARY
Tainted: [O]=OOT_MODULE
Stack:
 223721b3a80 6089eac6 00000001 00000001
 ffffff00 6089eac6 00000535 6086e528
 721b3ac0 6003c294 00000000 60031fc0
Call Trace:
 [<600407ed>] show_stack+0x10e/0x127
 [<6003c294>] dump_stack_lvl+0x77/0xc6
 [<6003c2fd>] dump_stack+0x1a/0x20
 [<600bc2f8>] lockdep_rcu_suspicious+0x116/0x13e
 [<603d8ea1>] dpm_async_suspend_superior+0x117/0x17e
 [<603d980f>] device_suspend+0x528/0x541
 [<603da24b>] dpm_suspend+0x1a2/0x267
 [<603da837>] dpm_suspend_start+0x5d/0x72
 [<600ca0c9>] suspend_devices_and_enter+0xab/0x736
 [...]

Add the fourth argument to the iteration to annotate
this and avoid the splat.

Fixes: 0679963 ("PM: sleep: Make async suspend handle suppliers like parents")
Fixes: ed18738 ("PM: sleep: Make async resume handle consumers like children")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20250826134348.aba79f6e6299.I9ecf55da46ccf33778f2c018a82e1819d815b348@changeid
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pull bot pushed a commit that referenced this pull request Aug 29, 2025
If preparing a write bio fails then blk_zone_wplug_bio_work() calls
bio_endio() with zwplug->lock held. If a device mapper driver is stacked
on top of the zoned block device then this results in nested locking of
zwplug->lock. The resulting lockdep complaint is a false positive
because this is nested locking and not recursive locking. Suppress this
false positive by calling blk_zone_wplug_bio_io_error() without holding
zwplug->lock. This is safe because no code in
blk_zone_wplug_bio_io_error() depends on zwplug->lock being held. This
patch suppresses the following lockdep complaint:

WARNING: possible recursive locking detected
--------------------------------------------
kworker/3:0H/46 is trying to acquire lock:
ffffff882968b830 (&zwplug->lock){-...}-{2:2}, at: blk_zone_write_plug_bio_endio+0x64/0x1f0

but task is already holding lock:
ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&zwplug->lock);
  lock(&zwplug->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by kworker/3:0H/46:
 #0: ffffff8809486758 ((wq_completion)sdd_zwplugs){+.+.}-{0:0}, at: process_one_work+0x1bc/0x65c
 #1: ffffffc085de3d70 ((work_completion)(&zwplug->bio_work)){+.+.}-{0:0}, at: process_one_work+0x1e4/0x65c
 #2: ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c

stack backtrace:
CPU: 3 UID: 0 PID: 46 Comm: kworker/3:0H Tainted: G        W  OE      6.12.38-android16-5-maybe-dirty-4k #1 8b362b6f76e3645a58cd27d86982bce10d150025
Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Spacecraft board based on MALIBU (DT)
Workqueue: sdd_zwplugs blk_zone_wplug_bio_work
Call trace:
 dump_backtrace+0xfc/0x17c
 show_stack+0x18/0x28
 dump_stack_lvl+0x40/0xa0
 dump_stack+0x18/0x24
 print_deadlock_bug+0x38c/0x398
 __lock_acquire+0x13e8/0x2e1c
 lock_acquire+0x134/0x2b4
 _raw_spin_lock_irqsave+0x5c/0x80
 blk_zone_write_plug_bio_endio+0x64/0x1f0
 bio_endio+0x9c/0x240
 __dm_io_complete+0x214/0x260
 clone_endio+0xe8/0x214
 bio_endio+0x218/0x240
 blk_zone_wplug_bio_work+0x204/0x48c
 process_one_work+0x26c/0x65c
 worker_thread+0x33c/0x498
 kthread+0x110/0x134
 ret_from_fork+0x10/0x20

Cc: stable@vger.kernel.org
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: dd291d7 ("block: Introduce zone write plugging")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250825182720.1697203-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
pull bot pushed a commit that referenced this pull request Aug 30, 2025
commit c652887 ("KVM: arm64: vgic-v3: Allow userspace to write
GICD_TYPER2.nASSGIcap") makes the allocation of vPEs depend on nASSGIcap
for GICv4.1 hosts. While the vGIC v4 initialization and teardown is
handled correctly, it erroneously attempts to establish a vLPI mapping
to a VM that has no vPEs allocated:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a8
   Mem abort info:
     ESR = 0x0000000096000044
     EC = 0x25: DABT (current EL), IL = 32 bits
     SET = 0, FnV = 0
     EA = 0, S1PTW = 0
     FSC = 0x04: level 0 translation fault
   Data abort info:
     ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
     CM = 0, WnR = 1, TnD = 0, TagAccess = 0
     GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
   user pgtable: 4k pages, 48-bit VAs, pgdp=00000073a453b000
   [00000000000000a8] pgd=0000000000000000, p4d=0000000000000000
   Internal error: Oops: 0000000096000044 [#1] SMP
   pstate: 23400009 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
   pc : its_irq_set_vcpu_affinity+0x58c/0x95c
   lr : its_irq_set_vcpu_affinity+0x1e0/0x95c
   sp : ffff8001029bb9e0
   pmr_save: 00000060
   x29: ffff8001029bba20 x28: ffff0001ca5e28c0 x27: 0000000000000000
   x26: 0000000000000000 x25: ffff00019eee9f80 x24: ffff0001992b3f00
   x23: ffff8001029bbab8 x22: ffff00001159fb80 x21: 00000000000024a7
   x20: 00000000000024a7 x19: ffff00019eee9fb4 x18: 0000000000000494
   x17: 000000000000000e x16: 0000000000000494 x15: 0000000000000002
   x14: ffff0001a7f34600 x13: ffffccaad1203000 x12: 0000000000000018
   x11: ffff000011991000 x10: 0000000000000000 x9 : 00000000000000a2
   x8 : 00000000000020a8 x7 : 0000000000000000 x6 : 000000000000003f
   x5 : 0000000000000040 x4 : 0000000000000000 x3 : 0000000000000004
   x2 : 0000000000000000 x1 : ffff8001029bbab8 x0 : 00000000000000a8
   Call trace:
    its_irq_set_vcpu_affinity+0x58c/0x95c
    irq_set_vcpu_affinity+0x74/0xc8
    its_map_vlpi+0x4c/0x94
    kvm_vgic_v4_set_forwarding+0x134/0x298
    kvm_arch_irq_bypass_add_producer+0x28/0x34
    irq_bypass_register_producer+0xf8/0x1d8
    vfio_msi_set_vector_signal+0x2c8/0x308
    vfio_pci_set_msi_trigger+0x198/0x2d4
    vfio_pci_set_irqs_ioctl+0xf0/0x104
    vfio_pci_core_ioctl+0x6ac/0xc5c
    vfio_device_fops_unl_ioctl+0x128/0x370
    __arm64_sys_ioctl+0x98/0xd0
    el0_svc_common+0xd8/0x1d8
    do_el0_svc+0x28/0x34
    el0_svc+0x40/0xb8
    el0t_64_sync_handler+0x70/0xbc
    el0t_64_sync+0x1a8/0x1ac
   Code: 321f0129 f940094a 8b08014 d1400900 (39000009)
   ---[ end trace 0000000000000000 ]---

Fix it by moving the GICv4.1 special-casing to
vgic_supports_direct_msis(), returning false if the user explicitly
disabled nASSGIcap for the VM.

Fixes: c652887 ("KVM: arm64: vgic-v3: Allow userspace to write GICD_TYPER2.nASSGIcap")
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Link: https://lore.kernel.org/r/20250729210644.830364-1-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
pull bot pushed a commit that referenced this pull request Aug 30, 2025
 into HEAD

KVM/riscv fixes for 6.17, take #1

- Fix pte settings within kvm_riscv_gstage_ioremap()
- Fix comments in kvm_riscv_check_vcpu_requests()
- Fix stack overrun when setting vlenb via ONE_REG
pull bot pushed a commit that referenced this pull request Aug 31, 2025
In gicv5_irs_of_init_affinity() a WARN_ON() is triggered if:

 1) a phandle in the "cpus" property does not correspond to a valid OF
    node
 2  a CPU logical id does not exist for a given OF cpu_node

#1 is a firmware bug and should be reported as such but does not warrant a
   WARN_ON() backtrace.

#2 is not necessarily an error condition (eg a kernel can be booted with
   nr_cpus=X limiting the number of cores artificially) and therefore there
   is no reason to clutter the kernel log with WARN_ON() output when the
   condition is hit.

Rework the IRS affinity parsing code to remove undue WARN_ON()s thus
making it less noisy.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250814094138.1611017-1-lpieralisi@kernel.org
pull bot pushed a commit that referenced this pull request Sep 2, 2025
When there are memory-only nodes (nodes without CPUs), these nodes are not
properly initialized, causing kernel panic during boot.

of_numa_init
	of_numa_parse_cpu_nodes
		node_set(nid, numa_nodes_parsed);
	of_numa_parse_memory_nodes

In of_numa_parse_cpu_nodes, numa_nodes_parsed gets updated only for nodes
containing CPUs.  Memory-only nodes should have been updated in
of_numa_parse_memory_nodes, but they weren't.

Subsequently, when free_area_init() attempts to access NODE_DATA() for
these uninitialized memory nodes, the kernel panics due to NULL pointer
dereference.

This can be reproduced on ARM64 QEMU with 1 CPU and 2 memory nodes:

qemu-system-aarch64 \
-cpu host -nographic \
-m 4G -smp 1 \
-machine virt,accel=kvm,gic-version=3,iommu=smmuv3 \
-object memory-backend-ram,size=2G,id=mem0 \
-object memory-backend-ram,size=2G,id=mem1 \
-numa node,nodeid=0,memdev=mem0 \
-numa node,nodeid=1,memdev=mem1 \
-kernel $IMAGE \
-hda $DISK \
-append "console=ttyAMA0 root=/dev/vda rw earlycon"

[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x481fd010]
[    0.000000] Linux version 6.17.0-rc1-00001-gabb4b3daf18c-dirty (yintirui@local) (gcc (GCC) 12.3.1, GNU ld (GNU Binutils) 2.41) #52 SMP PREEMPT Mon Aug 18 09:49:40 CST 2025
[    0.000000] KASLR enabled
[    0.000000] random: crng init done
[    0.000000] Machine model: linux,dummy-virt
[    0.000000] efi: UEFI not found.
[    0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
[    0.000000] printk: legacy bootconsole [pl11] enabled
[    0.000000] OF: reserved mem: Reserved memory: No reserved-memory node in the DT
[    0.000000] NODE_DATA(0) allocated [mem 0xbfffd9c0-0xbfffffff]
[    0.000000] node 1 must be removed before remove section 23
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000040000000-0x00000000ffffffff]
[    0.000000]   DMA32    empty
[    0.000000]   Normal   [mem 0x0000000100000000-0x000000013fffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000040000000-0x00000000bfffffff]
[    0.000000]   node   1: [mem 0x00000000c0000000-0x000000013fffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x00000000bfffffff]
[    0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0
[    0.000000] Mem abort info:
[    0.000000]   ESR = 0x0000000096000004
[    0.000000]   EC = 0x25: DABT (current EL), IL = 32 bits
[    0.000000]   SET = 0, FnV = 0
[    0.000000]   EA = 0, S1PTW = 0
[    0.000000]   FSC = 0x04: level 0 translation fault
[    0.000000] Data abort info:
[    0.000000]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[    0.000000]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    0.000000]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    0.000000] [00000000000000a0] user address but active_mm is swapper
[    0.000000] Internal error: Oops: 0000000096000004 [#1]  SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc1-00001-g760c6dabf762-dirty #54 PREEMPT
[    0.000000] Hardware name: linux,dummy-virt (DT)
[    0.000000] pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    0.000000] pc : free_area_init+0x50c/0xf9c
[    0.000000] lr : free_area_init+0x5c0/0xf9c
[    0.000000] sp : ffffa02ca0f33c00
[    0.000000] x29: ffffa02ca0f33cb0 x28: 0000000000000000 x27: 0000000000000000
[    0.000000] x26: 4ec4ec4ec4ec4ec5 x25: 00000000000c0000 x24: 00000000000c0000
[    0.000000] x23: 0000000000040000 x22: 0000000000000000 x21: ffffa02ca0f3b368
[    0.000000] x20: ffffa02ca14c7b98 x19: 0000000000000000 x18: 0000000000000002
[    0.000000] x17: 000000000000cacc x16: 0000000000000001 x15: 0000000000000001
[    0.000000] x14: 0000000080000000 x13: 0000000000000018 x12: 0000000000000002
[    0.000000] x11: ffffa02ca0fd4f00 x10: ffffa02ca14bab20 x9 : ffffa02ca14bab38
[    0.000000] x8 : 00000000000c0000 x7 : 0000000000000001 x6 : 0000000000000002
[    0.000000] x5 : 0000000140000000 x4 : ffffa02ca0f33c90 x3 : ffffa02ca0f33ca0
[    0.000000] x2 : ffffa02ca0f33c98 x1 : 0000000080000000 x0 : 0000000000000001
[    0.000000] Call trace:
[    0.000000]  free_area_init+0x50c/0xf9c (P)
[    0.000000]  bootmem_init+0x110/0x1dc
[    0.000000]  setup_arch+0x278/0x60c
[    0.000000]  start_kernel+0x70/0x748
[    0.000000]  __primary_switched+0x88/0x90
[    0.000000] Code: d503201f b98093e0 52800016 f8607a93 (f9405260)
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Link: https://lkml.kernel.org/r/20250819075510.2079961-1-yintirui@huawei.com
Fixes: 7675076 ("arch_numa: switch over to numa_memblks")
Signed-off-by: Yin Tirui <yintirui@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Chen Jun <chenjun102@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Sep 2, 2025
While working on the lazy MMU mode enablement for s390 I hit pretty
curious issues in the kasan code.

The first is related to a custom kasan-based sanitizer aimed at catching
invalid accesses to PTEs and is inspired by [1] conversation.  The kasan
complains on valid PTE accesses, while the shadow memory is reported as
unpoisoned:

[  102.783993] ==================================================================
[  102.784008] BUG: KASAN: out-of-bounds in set_pte_range+0x36c/0x390
[  102.784016] Read of size 8 at addr 0000780084cf9608 by task vmalloc_test/0/5542
[  102.784019] 
[  102.784040] CPU: 1 UID: 0 PID: 5542 Comm: vmalloc_test/0 Kdump: loaded Tainted: G           OE       6.16.0-gcc-ipte-kasan-11657-gb2d930c4950e #340 PREEMPT 
[  102.784047] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[  102.784049] Hardware name: IBM 8561 T01 703 (LPAR)
[  102.784052] Call Trace:
[  102.784054]  [<00007fffe0147ac0>] dump_stack_lvl+0xe8/0x140 
[  102.784059]  [<00007fffe0112484>] print_address_description.constprop.0+0x34/0x2d0 
[  102.784066]  [<00007fffe011282c>] print_report+0x10c/0x1f8 
[  102.784071]  [<00007fffe090785a>] kasan_report+0xfa/0x220 
[  102.784078]  [<00007fffe01d3dec>] set_pte_range+0x36c/0x390 
[  102.784083]  [<00007fffe01d41c2>] leave_ipte_batch+0x3b2/0xb10 
[  102.784088]  [<00007fffe07d3650>] apply_to_pte_range+0x2f0/0x4e0 
[  102.784094]  [<00007fffe07e62e4>] apply_to_pmd_range+0x194/0x3e0 
[  102.784099]  [<00007fffe07e820e>] __apply_to_page_range+0x2fe/0x7a0 
[  102.784104]  [<00007fffe07e86d8>] apply_to_page_range+0x28/0x40 
[  102.784109]  [<00007fffe090a3ec>] __kasan_populate_vmalloc+0xec/0x310 
[  102.784114]  [<00007fffe090aa36>] kasan_populate_vmalloc+0x96/0x130 
[  102.784118]  [<00007fffe0833a04>] alloc_vmap_area+0x3d4/0xf30 
[  102.784123]  [<00007fffe083a8ba>] __get_vm_area_node+0x1aa/0x4c0 
[  102.784127]  [<00007fffe083c4f6>] __vmalloc_node_range_noprof+0x126/0x4e0 
[  102.784131]  [<00007fffe083c980>] __vmalloc_node_noprof+0xd0/0x110 
[  102.784135]  [<00007fffe083ca32>] vmalloc_noprof+0x32/0x40 
[  102.784139]  [<00007fff608aa336>] fix_size_alloc_test+0x66/0x150 [test_vmalloc] 
[  102.784147]  [<00007fff608aa710>] test_func+0x2f0/0x430 [test_vmalloc] 
[  102.784153]  [<00007fffe02841f8>] kthread+0x3f8/0x7a0 
[  102.784159]  [<00007fffe014d8b4>] __ret_from_fork+0xd4/0x7d0 
[  102.784164]  [<00007fffe299c00a>] ret_from_fork+0xa/0x30 
[  102.784173] no locks held by vmalloc_test/0/5542.
[  102.784176] 
[  102.784178] The buggy address belongs to the physical page:
[  102.784186] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x84cf9
[  102.784198] flags: 0x3ffff00000000000(node=0|zone=1|lastcpupid=0x1ffff)
[  102.784212] page_type: f2(table)
[  102.784225] raw: 3ffff00000000000 0000000000000000 0000000000000122 0000000000000000
[  102.784234] raw: 0000000000000000 0000000000000000 f200000000000001 0000000000000000
[  102.784248] page dumped because: kasan: bad access detected
[  102.784250] 
[  102.784252] Memory state around the buggy address:
[  102.784260]  0000780084cf9500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784274]  0000780084cf9580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784277] >0000780084cf9600: fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784290]                          ^
[  102.784293]  0000780084cf9680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784303]  0000780084cf9700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  102.784306] ==================================================================

The second issue hits when the custom sanitizer above is not implemented,
but the kasan itself is still active:

[ 1554.438028] Unable to handle kernel pointer dereference in virtual kernel address space
[ 1554.438065] Failing address: 001c0ff0066f0000 TEID: 001c0ff0066f0403
[ 1554.438076] Fault in home space mode while using kernel ASCE.
[ 1554.438103] AS:00000000059d400b R2:0000000ffec5c00b R3:00000000c6c9c007 S:0000000314470001 P:00000000d0ab413d 
[ 1554.438158] Oops: 0011 ilc:2 [#1]SMP 
[ 1554.438175] Modules linked in: test_vmalloc(E+) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) sunrpc(E) pkey_pckmo(E) uvdevice(E) s390_trng(E) rng_core(E) eadm_sch(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) loop(E) i2c_core(E) drm_panel_orientation_quirks(E) nfnetlink(E) ctcm(E) fsm(E) zfcp(E) scsi_transport_fc(E) diag288_wdt(E) watchdog(E) ghash_s390(E) prng(E) aes_s390(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha512_s390(E) sha1_s390(E) sha_common(E) pkey(E) autofs4(E)
[ 1554.438319] Unloaded tainted modules: pkey_uv(E):1 hmac_s390(E):2
[ 1554.438354] CPU: 1 UID: 0 PID: 1715 Comm: vmalloc_test/0 Kdump: loaded Tainted: G            E       6.16.0-gcc-ipte-kasan-11657-gb2d930c4950e #350 PREEMPT 
[ 1554.438368] Tainted: [E]=UNSIGNED_MODULE
[ 1554.438374] Hardware name: IBM 8561 T01 703 (LPAR)
[ 1554.438381] Krnl PSW : 0704e00180000000 00007fffe1d3d6ae (memset+0x5e/0x98)
[ 1554.438396]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
[ 1554.438409] Krnl GPRS: 0000000000000001 001c0ff0066f0000 001c0ff0066f0000 00000000000000f8
[ 1554.438418]            00000000000009fe 0000000000000009 0000000000000000 0000000000000002
[ 1554.438426]            0000000000005000 000078031ae655c8 00000feffdcf9f59 0000780258672a20
[ 1554.438433]            0000780243153500 00007f8033780000 00007fffe083a510 00007f7fee7cfa00
[ 1554.438452] Krnl Code: 00007fffe1d3d6a0: eb540008000c	srlg	%r5,%r4,8
           00007fffe1d3d6a6: b9020055		ltgr	%r5,%r5
          #00007fffe1d3d6aa: a784000b		brc	8,00007fffe1d3d6c0
          >00007fffe1d3d6ae: 42301000		stc	%r3,0(%r1)
           00007fffe1d3d6b2: d2fe10011000	mvc	1(255,%r1),0(%r1)
           00007fffe1d3d6b8: 41101100		la	%r1,256(%r1)
           00007fffe1d3d6bc: a757fff9		brctg	%r5,00007fffe1d3d6ae
           00007fffe1d3d6c0: 42301000		stc	%r3,0(%r1)
[ 1554.438539] Call Trace:
[ 1554.438545]  [<00007fffe1d3d6ae>] memset+0x5e/0x98 
[ 1554.438552] ([<00007fffe083a510>] remove_vm_area+0x220/0x400)
[ 1554.438562]  [<00007fffe083a9d6>] vfree.part.0+0x26/0x810 
[ 1554.438569]  [<00007fff6073bd50>] fix_align_alloc_test+0x50/0x90 [test_vmalloc] 
[ 1554.438583]  [<00007fff6073c73a>] test_func+0x46a/0x6c0 [test_vmalloc] 
[ 1554.438593]  [<00007fffe0283ac8>] kthread+0x3f8/0x7a0 
[ 1554.438603]  [<00007fffe014d8b4>] __ret_from_fork+0xd4/0x7d0 
[ 1554.438613]  [<00007fffe299ac0a>] ret_from_fork+0xa/0x30 
[ 1554.438622] INFO: lockdep is turned off.
[ 1554.438627] Last Breaking-Event-Address:
[ 1554.438632]  [<00007fffe1d3d65c>] memset+0xc/0x98
[ 1554.438644] Kernel panic - not syncing: Fatal exception: panic_on_oops

This series fixes the above issues and is a pre-requisite for the s390
lazy MMU mode implementation.

test_vmalloc was used to stress-test the fixes.


This patch (of 2):

When vmalloc shadow memory is established the modification of the
corresponding page tables is not protected by any locks.  Instead, the
locking is done per-PTE.  This scheme however has defects.

kasan_populate_vmalloc_pte() - while ptep_get() read is atomic the
sequence pte_none(ptep_get()) is not.  Doing that outside of the lock
might lead to a concurrent PTE update and what could be seen as a shadow
memory corruption as result.

kasan_depopulate_vmalloc_pte() - by the time a page whose address was
extracted from ptep_get() read and cached in a local variable outside of
the lock is attempted to get free, could actually be freed already.

To avoid these put ptep_get() itself and the code that manipulates the
result of the read under lock.  In addition, move freeing of the page out
of the atomic context.

Link: https://lkml.kernel.org/r/cover.1755528662.git.agordeev@linux.ibm.com
Link: https://lkml.kernel.org/r/adb258634194593db294c0d1fb35646e894d6ead.1755528662.git.agordeev@linux.ibm.com
Link: https://lore.kernel.org/linux-mm/5b0609c9-95ee-4e48-bb6d-98f57c5d2c31@arm.com/ [1]
Fixes: 3c5c3cf ("kasan: support backing vmalloc space with real shadow memory")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Sep 2, 2025
During our internal testing, we started observing intermittent boot
failures when the machine uses 4-level paging and has a large amount of
persistent memory:

  BUG: unable to handle page fault for address: ffffe70000000034
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0 
  Oops: 0002 [#1] SMP NOPTI
  RIP: 0010:__init_single_page+0x9/0x6d
  Call Trace:
   <TASK>
   __init_zone_device_page+0x17/0x5d
   memmap_init_zone_device+0x154/0x1bb
   pagemap_range+0x2e0/0x40f
   memremap_pages+0x10b/0x2f0
   devm_memremap_pages+0x1e/0x60
   dev_dax_probe+0xce/0x2ec [device_dax]
   dax_bus_probe+0x6d/0xc9
   [... snip ...]
   </TASK>

It turns out that the kernel panics while initializing vmemmap (struct
page array) when the vmemmap region spans two PGD entries, because the new
PGD entry is only installed in init_mm.pgd, but not in the page tables of
other tasks.

And looking at __populate_section_memmap():
  if (vmemmap_can_optimize(altmap, pgmap))                                
          // does not sync top level page tables
          r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap);
  else                                                                    
          // sync top level page tables in x86
          r = vmemmap_populate(start, end, nid, altmap);

In the normal path, vmemmap_populate() in arch/x86/mm/init_64.c
synchronizes the top level page table (See commit 9b86152 ("x86-64,
mem: Update all PGDs for direct mapping and vmemmap mapping changes")) so
that all tasks in the system can see the new vmemmap area.

However, when vmemmap_can_optimize() returns true, the optimized path
skips synchronization of top-level page tables.  This is because
vmemmap_populate_compound_pages() is implemented in core MM code, which
does not handle synchronization of the top-level page tables.  Instead,
the core MM has historically relied on each architecture to perform this
synchronization manually.

We're not the first party to encounter a crash caused by not-sync'd top
level page tables: earlier this year, Gwan-gyeong Mun attempted to address
the issue [1] [2] after hitting a kernel panic when x86 code accessed the
vmemmap area before the corresponding top-level entries were synced.  At
that time, the issue was believed to be triggered only when struct page
was enlarged for debugging purposes, and the patch did not get further
updates.

It turns out that current approach of relying on each arch to handle the
page table sync manually is fragile because 1) it's easy to forget to sync
the top level page table, and 2) it's also easy to overlook that the
kernel should not access the vmemmap and direct mapping areas before the
sync.

# The solution: Make page table sync more code robust and harder to miss

To address this, Dave Hansen suggested [3] [4] introducing
{pgd,p4d}_populate_kernel() for updating kernel portion of the page tables
and allow each architecture to explicitly perform synchronization when
installing top-level entries.  With this approach, we no longer need to
worry about missing the sync step, reducing the risk of future
regressions.

The new interface reuses existing ARCH_PAGE_TABLE_SYNC_MASK,
PGTBL_P*D_MODIFIED and arch_sync_kernel_mappings() facility used by
vmalloc and ioremap to synchronize page tables.

pgd_populate_kernel() looks like this:
static inline void pgd_populate_kernel(unsigned long addr, pgd_t *pgd,
                                       p4d_t *p4d)
{
        pgd_populate(&init_mm, pgd, p4d);
        if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_PGD_MODIFIED)
                arch_sync_kernel_mappings(addr, addr);
}

It is worth noting that vmalloc() and apply_to_range() carefully
synchronizes page tables by calling p*d_alloc_track() and
arch_sync_kernel_mappings(), and thus they are not affected by this patch
series.

This series was hugely inspired by Dave Hansen's suggestion and hence
added Suggested-by: Dave Hansen.

Cc stable because lack of this series opens the door to intermittent
boot failures.


This patch (of 3):

Move ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to
linux/pgtable.h so that they can be used outside of vmalloc and ioremap.

Link: https://lkml.kernel.org/r/20250818020206.4517-1-harry.yoo@oracle.com
Link: https://lkml.kernel.org/r/20250818020206.4517-2-harry.yoo@oracle.com
Link: https://lore.kernel.org/linux-mm/20250220064105.808339-1-gwan-gyeong.mun@intel.com [1] 
Link: https://lore.kernel.org/linux-mm/20250311114420.240341-1-gwan-gyeong.mun@intel.com [2] 
Link: https://lore.kernel.org/linux-mm/d1da214c-53d3-45ac-a8b6-51821c5416e4@intel.com [3] 
Link: https://lore.kernel.org/linux-mm/4d800744-7b88-41aa-9979-b245e8bf794b@intel.com  [4] 
Fixes: 8d40091 ("x86/vmemmap: handle unpopulated sub-pmd ranges")
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: bibo mao <maobibo@loongson.cn>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Sep 2, 2025
…ings()

Define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure
page tables are properly synchronized when calling p*d_populate_kernel().

For 5-level paging, synchronization is performed via
pgd_populate_kernel().  In 4-level paging, pgd_populate() is a no-op, so
synchronization is instead performed at the P4D level via
p4d_populate_kernel().

This fixes intermittent boot failures on systems using 4-level paging and
a large amount of persistent memory:

  BUG: unable to handle page fault for address: ffffe70000000034
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  RIP: 0010:__init_single_page+0x9/0x6d
  Call Trace:
   <TASK>
   __init_zone_device_page+0x17/0x5d
   memmap_init_zone_device+0x154/0x1bb
   pagemap_range+0x2e0/0x40f
   memremap_pages+0x10b/0x2f0
   devm_memremap_pages+0x1e/0x60
   dev_dax_probe+0xce/0x2ec [device_dax]
   dax_bus_probe+0x6d/0xc9
   [... snip ...]
   </TASK>

It also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap
before sync_global_pgds() [1]:

  BUG: unable to handle page fault for address: ffffeb3ff1200000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI
  Tainted: [W]=WARN
  RIP: 0010:vmemmap_set_pmd+0xff/0x230
   <TASK>
   vmemmap_populate_hugepages+0x176/0x180
   vmemmap_populate+0x34/0x80
   __populate_section_memmap+0x41/0x90
   sparse_add_section+0x121/0x3e0
   __add_pages+0xba/0x150
   add_pages+0x1d/0x70
   memremap_pages+0x3dc/0x810
   devm_memremap_pages+0x1c/0x60
   xe_devm_add+0x8b/0x100 [xe]
   xe_tile_init_noalloc+0x6a/0x70 [xe]
   xe_device_probe+0x48c/0x740 [xe]
   [... snip ...]

Link: https://lkml.kernel.org/r/20250818020206.4517-4-harry.yoo@oracle.com
Fixes: 8d40091 ("x86/vmemmap: handle unpopulated sub-pmd ranges")
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Closes: https://lore.kernel.org/linux-mm/20250311114420.240341-1-gwan-gyeong.mun@intel.com [1]
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: bibo mao <maobibo@loongson.cn>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Sep 3, 2025
tee_shm_put have NULL pointer dereference:

__optee_disable_shm_cache -->
	shm = reg_pair_to_ptr(...);//shm maybe return NULL
        tee_shm_free(shm); -->
		tee_shm_put(shm);//crash

Add check in tee_shm_put to fix it.

panic log:
Unable to handle kernel paging request at virtual address 0000000000100cca
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=0000002049d07000
[0000000000100cca] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] SMP
CPU: 2 PID: 14442 Comm: systemd-sleep Tainted: P OE ------- ----
6.6.0-39-generic #38
Source Version: 938b255f6cb8817c95b0dd5c8c2944acfce94b07
Hardware name: greatwall GW-001Y1A-FTH, BIOS Great Wall BIOS V3.0
10/26/2022
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : tee_shm_put+0x24/0x188
lr : tee_shm_free+0x14/0x28
sp : ffff001f98f9faf0
x29: ffff001f98f9faf0 x28: ffff0020df543cc0 x27: 0000000000000000
x26: ffff001f811344a0 x25: ffff8000818dac00 x24: ffff800082d8d048
x23: ffff001f850fcd18 x22: 0000000000000001 x21: ffff001f98f9fb88
x20: ffff001f83e76218 x19: ffff001f83e761e0 x18: 000000000000ffff
x17: 303a30303a303030 x16: 0000000000000000 x15: 0000000000000003
x14: 0000000000000001 x13: 0000000000000000 x12: 0101010101010101
x11: 0000000000000001 x10: 0000000000000001 x9 : ffff800080e08d0c
x8 : ffff001f98f9fb88 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : ffff001f83e761e0 x1 : 00000000ffff001f x0 : 0000000000100cca
Call trace:
tee_shm_put+0x24/0x188
tee_shm_free+0x14/0x28
__optee_disable_shm_cache+0xa8/0x108
optee_shutdown+0x28/0x38
platform_shutdown+0x28/0x40
device_shutdown+0x144/0x2b0
kernel_power_off+0x3c/0x80
hibernate+0x35c/0x388
state_store+0x64/0x80
kobj_attr_store+0x14/0x28
sysfs_kf_write+0x48/0x60
kernfs_fop_write_iter+0x128/0x1c0
vfs_write+0x270/0x370
ksys_write+0x6c/0x100
__arm64_sys_write+0x20/0x30
invoke_syscall+0x4c/0x120
el0_svc_common.constprop.0+0x44/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x24/0x88
el0t_64_sync_handler+0x134/0x150
el0t_64_sync+0x14c/0x15

Fixes: dfd0743 ("tee: handle lookup of shm with reference count 0")
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
pull bot pushed a commit that referenced this pull request Sep 3, 2025
sched_numa_find_nth_cpu() uses a bsearch to look for the 'closest'
CPU in sched_domains_numa_masks and given cpus mask. However they
might not intersect if all CPUs in the cpus mask are offline. bsearch
will return NULL in that case, bail out instead of dereferencing a
bogus pointer.

The previous behaviour lead to this bug when using maxcpus=4 on an
rk3399 (LLLLbb) (i.e. booting with all big CPUs offline):

[    1.422922] Unable to handle kernel paging request at virtual address ffffff8000000000
[    1.423635] Mem abort info:
[    1.423889]   ESR = 0x0000000096000006
[    1.424227]   EC = 0x25: DABT (current EL), IL = 32 bits
[    1.424715]   SET = 0, FnV = 0
[    1.424995]   EA = 0, S1PTW = 0
[    1.425279]   FSC = 0x06: level 2 translation fault
[    1.425735] Data abort info:
[    1.425998]   ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
[    1.426499]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    1.426952]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    1.427428] swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000004a9f000
[    1.428038] [ffffff8000000000] pgd=18000000f7fff403, p4d=18000000f7fff403, pud=18000000f7fff403, pmd=0000000000000000
[    1.429014] Internal error: Oops: 0000000096000006 [#1]  SMP
[    1.429525] Modules linked in:
[    1.429813] CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-rc4-dirty #343 PREEMPT
[    1.430559] Hardware name: Pine64 RockPro64 v2.1 (DT)
[    1.431012] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    1.431634] pc : sched_numa_find_nth_cpu+0x2a0/0x488
[    1.432094] lr : sched_numa_find_nth_cpu+0x284/0x488
[    1.432543] sp : ffffffc084e1b960
[    1.432843] x29: ffffffc084e1b960 x28: ffffff80078a8800 x27: ffffffc0846eb1d0
[    1.433495] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
[    1.434144] x23: 0000000000000000 x22: fffffffffff7f093 x21: ffffffc081de6378
[    1.434792] x20: 0000000000000000 x19: 0000000ffff7f093 x18: 00000000ffffffff
[    1.435441] x17: 3030303866666666 x16: 66663d736b73616d x15: ffffffc104e1b5b7
[    1.436091] x14: 0000000000000000 x13: ffffffc084712860 x12: 0000000000000372
[    1.436739] x11: 0000000000000126 x10: ffffffc08476a860 x9 : ffffffc084712860
[    1.437389] x8 : 00000000ffffefff x7 : ffffffc08476a860 x6 : 0000000000000000
[    1.438036] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000
[    1.438683] x2 : 0000000000000000 x1 : ffffffc0846eb000 x0 : ffffff8000407b68
[    1.439332] Call trace:
[    1.439559]  sched_numa_find_nth_cpu+0x2a0/0x488 (P)
[    1.440016]  smp_call_function_any+0xc8/0xd0
[    1.440416]  armv8_pmu_init+0x58/0x27c
[    1.440770]  armv8_cortex_a72_pmu_init+0x20/0x2c
[    1.441199]  arm_pmu_device_probe+0x1e4/0x5e8
[    1.441603]  armv8_pmu_device_probe+0x1c/0x28
[    1.442007]  platform_probe+0x5c/0xac
[    1.442347]  really_probe+0xbc/0x298
[    1.442683]  __driver_probe_device+0x78/0x12c
[    1.443087]  driver_probe_device+0xdc/0x160
[    1.443475]  __driver_attach+0x94/0x19c
[    1.443833]  bus_for_each_dev+0x74/0xd4
[    1.444190]  driver_attach+0x24/0x30
[    1.444525]  bus_add_driver+0xe4/0x208
[    1.444874]  driver_register+0x60/0x128
[    1.445233]  __platform_driver_register+0x24/0x30
[    1.445662]  armv8_pmu_driver_init+0x28/0x4c
[    1.446059]  do_one_initcall+0x44/0x25c
[    1.446416]  kernel_init_freeable+0x1dc/0x3bc
[    1.446820]  kernel_init+0x20/0x1d8
[    1.447151]  ret_from_fork+0x10/0x20
[    1.447493] Code: 90022e21 f000e5f5 910de2b5 2a1703e2 (f8767803)
[    1.448040] ---[ end trace 0000000000000000 ]---
[    1.448483] note: swapper/0[1] exited with preempt_count 1
[    1.449047] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[    1.449741] SMP: stopping secondary CPUs
[    1.450105] Kernel Offset: disabled
[    1.450419] CPU features: 0x000000,00080000,20002001,0400421b
[    1.450935] Memory Limit: none
[    1.451217] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

Yury: with the fix, the function returns cpu == nr_cpu_ids, and later in

	smp_call_function_any ->
	  smp_call_function_single ->
	     generic_exec_single

we test the cpu for '>= nr_cpu_ids' and return -ENXIO. So everything is
handled correctly.

Fixes: cd7f553 ("sched: add sched_numa_find_nth_cpu()")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
pull bot pushed a commit that referenced this pull request Sep 4, 2025
BUG: kernel NULL pointer dereference, address: 00000000000002ec
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G        OE       6.17.0-rc2+ #9 NONE
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Workqueue: smc_hs_wq smc_listen_work [smc]
RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
...
Call Trace:
 <TASK>
 smcr_buf_map_link+0x211/0x2a0 [smc]
 __smc_buf_create+0x522/0x970 [smc]
 smc_buf_create+0x3a/0x110 [smc]
 smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
 ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
 smc_listen_find_device+0x1dd/0x2b0 [smc]
 smc_listen_work+0x30f/0x580 [smc]
 process_one_work+0x18c/0x340
 worker_thread+0x242/0x360
 kthread+0xe7/0x220
 ret_from_fork+0x13a/0x160
 ret_from_fork_asm+0x1a/0x30
 </TASK>

If the software RoCE device is used, ibdev->dma_device is a null pointer.
As a result, the problem occurs. Null pointer detection is added to
prevent problems.

Fixes: 0ef69e7 ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Link: https://patch.msgid.link/20250828124117.2622624-1-liujian56@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
pull bot pushed a commit that referenced this pull request Sep 4, 2025
VXLAN FDB entries can point to either a remote destination or an FDB
nexthop group. The latter is usually used in EVPN deployments where
learning is disabled.

However, when learning is enabled, an incoming packet might try to
refresh an FDB entry that points to an FDB nexthop group and therefore
does not have a remote. Such packets should be dropped, but they are
only dropped after dereferencing the non-existent remote, resulting in a
NPD [1] which can be reproduced using [2].

Fix by dropping such packets earlier. Remove the misleading comment from
first_remote_rcu().

[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 13 UID: 0 PID: 361 Comm: mausezahn Not tainted 6.17.0-rc1-virtme-g9f6b606b6b37 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:vxlan_snoop+0x98/0x1e0
[...]
Call Trace:
 <TASK>
 vxlan_encap_bypass+0x209/0x240
 encap_bypass_if_local+0xb1/0x100
 vxlan_xmit_one+0x1375/0x17e0
 vxlan_xmit+0x6b4/0x15f0
 dev_hard_start_xmit+0x5d/0x1c0
 __dev_queue_xmit+0x246/0xfd0
 packet_sendmsg+0x113a/0x1850
 __sock_sendmsg+0x38/0x70
 __sys_sendto+0x126/0x180
 __x64_sys_sendto+0x24/0x30
 do_syscall_64+0xa4/0x260
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

[2]
 #!/bin/bash

 ip address add 192.0.2.1/32 dev lo
 ip address add 192.0.2.2/32 dev lo

 ip nexthop add id 1 via 192.0.2.3 fdb
 ip nexthop add id 10 group 1 fdb

 ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 12345 localbypass
 ip link add name vx1 up type vxlan id 10020 local 192.0.2.2 dstport 54321 learning

 bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 192.0.2.2 port 54321 vni 10020
 bridge fdb add 00:aa:bb:cc:dd:ee dev vx1 self static nhid 10

 mausezahn vx0 -a 00:aa:bb:cc:dd:ee -b 00:11:22:33:44:55 -c 1 -q

Fixes: 1274e1c ("vxlan: ecmp support for mac fdb entries")
Reported-by: Marlin Cremers <mcremers@cloudbear.nl>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250901065035.159644-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Sep 4, 2025
Ido Schimmel says:

====================
vxlan: Fix NPDs when using nexthop objects

With FDB nexthop groups, VXLAN FDB entries do not necessarily point to
a remote destination but rather to an FDB nexthop group. This means that
first_remote_{rcu,rtnl}() can return NULL and a few places in the driver
were not ready for that, resulting in NULL pointer dereferences.
Patches #1-#2 fix these NPDs.

Note that vxlan_fdb_find_uc() still dereferences the remote returned by
first_remote_rcu() without checking that it is not NULL, but this
function is only invoked by a single driver which vetoes the creation of
FDB nexthop groups. I will patch this in net-next to make the code less
fragile.

Patch #3 adds a selftests which exercises these code paths and tests
basic Tx functionality with FDB nexthop groups. I verified that the test
crashes the kernel without the first two patches.
====================

Link: https://patch.msgid.link/20250901065035.159644-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Sep 4, 2025
When transmitting a PTP frame which is timestamp using 2 step, the
following warning appears if CONFIG_PROVE_LOCKING is enabled:
=============================
[ BUG: Invalid wait context ]
6.17.0-rc1-00326-ge6160462704e #427 Not tainted
-----------------------------
ptp4l/119 is trying to lock:
c2a44ed4 (&vsc8531->ts_lock){+.+.}-{3:3}, at: vsc85xx_txtstamp+0x50/0xac
other info that might help us debug this:
context-{4:4}
4 locks held by ptp4l/119:
 #0: c145f068 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x58/0x1440
 #1: c29df974 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x5c4/0x1440
 #2: c2aaaad0 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x108/0x350
 #3: c2aac170 (&lan966x->tx_lock){+.-.}-{2:2}, at: lan966x_port_xmit+0xd0/0x350
stack backtrace:
CPU: 0 UID: 0 PID: 119 Comm: ptp4l Not tainted 6.17.0-rc1-00326-ge6160462704e #427 NONE
Hardware name: Generic DT based system
Call trace:
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x7c/0xac
 dump_stack_lvl from __lock_acquire+0x8e8/0x29dc
 __lock_acquire from lock_acquire+0x108/0x38c
 lock_acquire from __mutex_lock+0xb0/0xe78
 __mutex_lock from mutex_lock_nested+0x1c/0x24
 mutex_lock_nested from vsc85xx_txtstamp+0x50/0xac
 vsc85xx_txtstamp from lan966x_fdma_xmit+0xd8/0x3a8
 lan966x_fdma_xmit from lan966x_port_xmit+0x1bc/0x350
 lan966x_port_xmit from dev_hard_start_xmit+0xc8/0x2c0
 dev_hard_start_xmit from sch_direct_xmit+0x8c/0x350
 sch_direct_xmit from __dev_queue_xmit+0x680/0x1440
 __dev_queue_xmit from packet_sendmsg+0xfa4/0x1568
 packet_sendmsg from __sys_sendto+0x110/0x19c
 __sys_sendto from sys_send+0x18/0x20
 sys_send from ret_fast_syscall+0x0/0x1c
Exception stack(0xf0b05fa8 to 0xf0b05ff0)
5fa0:                   00000001 0000000 0000000 0004b47a 0000003a 00000000
5fc0: 00000001 0000000 00000000 00000121 0004af58 00044874 00000000 00000000
5fe0: 00000001 bee9d420 00025a10 b6e75c7c

So, instead of using the ts_lock for tx_queue, use the spinlock that
skb_buff_head has.

Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Fixes: 7d272e6 ("net: phy: mscc: timestamping and PHC support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://patch.msgid.link/20250902121259.3257536-1-horatiu.vultur@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pull bot pushed a commit that referenced this pull request Sep 8, 2025
The commit ced17ee ("Revert "virtio: reject shm region if length is zero"")
exposes the following DAX page fault bug (this fix the failure that getting shm
region alway returns false because of zero length):

The commit 21aa65b ("mm: remove callers of pfn_t functionality") handles
the DAX physical page address incorrectly: the removed macro 'phys_to_pfn_t()'
should be replaced with 'PHYS_PFN()'.

[    1.390321] BUG: unable to handle page fault for address: ffffd3fb40000008
[    1.390875] #PF: supervisor read access in kernel mode
[    1.391257] #PF: error_code(0x0000) - not-present page
[    1.391509] PGD 0 P4D 0
[    1.391626] Oops: Oops: 0000 [#1] SMP NOPTI
[    1.391806] CPU: 6 UID: 1000 PID: 162 Comm: weston Not tainted 6.17.0-rc3-WSL2-STABLE #2 PREEMPT(none)
[    1.392361] RIP: 0010:dax_to_folio+0x14/0x60
[    1.392653] Code: 52 c9 c3 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 c1 ef 05 48 c1 e7 06 48 03 3d 34 b5 31 01 <48> 8b 57 08 48 89 f8 f6 c2 01 75 2b 66 90 c3 cc cc cc cc f7 c7 ff
[    1.393727] RSP: 0000:ffffaf7d04407aa8 EFLAGS: 00010086
[    1.394003] RAX: 000000a000000000 RBX: ffffaf7d04407bb0 RCX: 0000000000000000
[    1.394524] RDX: ffffd17b40000008 RSI: 0000000000000083 RDI: ffffd3fb40000000
[    1.394967] RBP: 0000000000000011 R08: 000000a000000000 R09: 0000000000000000
[    1.395400] R10: 0000000000001000 R11: ffffaf7d04407c10 R12: 0000000000000000
[    1.395806] R13: ffffa020557be9c0 R14: 0000014000000001 R15: 0000725970e94000
[    1.396268] FS:  000072596d6d2ec0(0000) GS:ffffa0222dc59000(0000) knlGS:0000000000000000
[    1.396715] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.397100] CR2: ffffd3fb40000008 CR3: 000000011579c005 CR4: 0000000000372ef0
[    1.397518] Call Trace:
[    1.397663]  <TASK>
[    1.397900]  dax_insert_entry+0x13b/0x390
[    1.398179]  dax_fault_iter+0x2a5/0x6c0
[    1.398443]  dax_iomap_pte_fault+0x193/0x3c0
[    1.398750]  __fuse_dax_fault+0x8b/0x270
[    1.398997]  ? vm_mmap_pgoff+0x161/0x210
[    1.399175]  __do_fault+0x30/0x180
[    1.399360]  do_fault+0xc4/0x550
[    1.399547]  __handle_mm_fault+0x8e3/0xf50
[    1.399731]  ? do_syscall_64+0x72/0x1e0
[    1.399958]  handle_mm_fault+0x192/0x2f0
[    1.400204]  do_user_addr_fault+0x20e/0x700
[    1.400418]  exc_page_fault+0x66/0x150
[    1.400602]  asm_exc_page_fault+0x26/0x30
[    1.400831] RIP: 0033:0x72596d1bf703
[    1.401076] Code: 31 f6 45 31 e4 48 8d 15 b3 73 00 00 e8 06 03 00 00 8b 83 68 01 00 00 e9 8e fa ff ff 0f 1f 00 48 8b 44 24 08 4c 89 ee 48 89 df <c7> 00 21 43 34 12 e8 72 09 00 00 e9 6a fa ff ff 0f 1f 44 00 00 e8
[    1.402172] RSP: 002b:00007ffc350f6dc0 EFLAGS: 00010202
[    1.402488] RAX: 0000725970e94000 RBX: 00005b7c642c2560 RCX: 0000725970d359a7
[    1.402898] RDX: 0000000000000003 RSI: 00007ffc350f6dc0 RDI: 00005b7c642c2560
[    1.403284] RBP: 00007ffc350f6e90 R08: 000000000000000d R09: 0000000000000000
[    1.403634] R10: 00007ffc350f6dd8 R11: 0000000000000246 R12: 0000000000000001
[    1.404078] R13: 00007ffc350f6dc0 R14: 0000725970e29ce0 R15: 0000000000000003
[    1.404450]  </TASK>
[    1.404570] Modules linked in:
[    1.404821] CR2: ffffd3fb40000008
[    1.405029] ---[ end trace 0000000000000000 ]---
[    1.405323] RIP: 0010:dax_to_folio+0x14/0x60
[    1.405556] Code: 52 c9 c3 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 c1 ef 05 48 c1 e7 06 48 03 3d 34 b5 31 01 <48> 8b 57 08 48 89 f8 f6 c2 01 75 2b 66 90 c3 cc cc cc cc f7 c7 ff
[    1.406639] RSP: 0000:ffffaf7d04407aa8 EFLAGS: 00010086
[    1.406910] RAX: 000000a000000000 RBX: ffffaf7d04407bb0 RCX: 0000000000000000
[    1.407379] RDX: ffffd17b40000008 RSI: 0000000000000083 RDI: ffffd3fb40000000
[    1.407800] RBP: 0000000000000011 R08: 000000a000000000 R09: 0000000000000000
[    1.408246] R10: 0000000000001000 R11: ffffaf7d04407c10 R12: 0000000000000000
[    1.408666] R13: ffffa020557be9c0 R14: 0000014000000001 R15: 0000725970e94000
[    1.409170] FS:  000072596d6d2ec0(0000) GS:ffffa0222dc59000(0000) knlGS:0000000000000000
[    1.409608] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.409977] CR2: ffffd3fb40000008 CR3: 000000011579c005 CR4: 0000000000372ef0
[    1.410437] Kernel panic - not syncing: Fatal exception
[    1.410857] Kernel Offset: 0xc000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Fixes: 21aa65b ("mm: remove callers of pfn_t functionality")
Signed-off-by: Haiyue Wang <haiyuewa@163.com>
Link: https://lore.kernel.org/20250904120339.972-1-haiyuewa@163.com
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
pull bot pushed a commit that referenced this pull request Sep 10, 2025
A crash was observed with the following output:

BUG: kernel NULL pointer dereference, address: 0000000000000010
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 92 Comm: osnoise_cpus Not tainted 6.17.0-rc4-00201-gd69eb204c255 #138 PREEMPT(voluntary)
RIP: 0010:bitmap_parselist+0x53/0x3e0
Call Trace:
 <TASK>
 osnoise_cpus_write+0x7a/0x190
 vfs_write+0xf8/0x410
 ? do_sys_openat2+0x88/0xd0
 ksys_write+0x60/0xd0
 do_syscall_64+0xa4/0x260
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
 </TASK>

This issue can be reproduced by below code:

fd=open("/sys/kernel/debug/tracing/osnoise/cpus", O_WRONLY);
write(fd, "0-2", 0);

When user pass 'count=0' to osnoise_cpus_write(), kmalloc() will return
ZERO_SIZE_PTR (16) and cpulist_parse() treat it as a normal value, which
trigger the null pointer dereference. Add check for the parameter 'count'.

Cc: <mhiramat@kernel.org>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <tglozar@redhat.com>
Link: https://lore.kernel.org/20250906035610.3880282-1-wangliang74@huawei.com
Fixes: 17f8910 ("tracing/osnoise: Allow arbitrarily long CPU string")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
pull bot pushed a commit that referenced this pull request Sep 11, 2025
Steven Rostedt reported a crash with "ftrace=function" kernel command
line:

[    0.159269] BUG: kernel NULL pointer dereference, address: 000000000000001c
[    0.160254] #PF: supervisor read access in kernel mode
[    0.160975] #PF: error_code(0x0000) - not-present page
[    0.161697] PGD 0 P4D 0
[    0.162055] Oops: Oops: 0000 [#1] SMP PTI
[    0.162619] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc2-test-00006-g48d06e78b7cb-dirty #9 PREEMPT(undef)
[    0.164141] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[    0.165439] RIP: 0010:kmem_cache_alloc_noprof (mm/slub.c:4237)
[ 0.166186] Code: 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 fc 53 48 83 e4 f0 48 83 ec 20 8b 05 c9 b6 7e 01 <44> 8b 77 1c 65 4c 8b 2d b5 ea 20 02 4c 89 6c 24 18 41 89 f5 21 f0
[    0.168811] RSP: 0000:ffffffffb2e03b30 EFLAGS: 00010086
[    0.169545] RAX: 0000000001fff33f RBX: 0000000000000000 RCX: 0000000000000000
[    0.170544] RDX: 0000000000002800 RSI: 0000000000002800 RDI: 0000000000000000
[    0.171554] RBP: ffffffffb2e03b80 R08: 0000000000000004 R09: ffffffffb2e03c90
[    0.172549] R10: ffffffffb2e03c90 R11: 0000000000000000 R12: 0000000000000000
[    0.173544] R13: ffffffffb2e03c90 R14: ffffffffb2e03c90 R15: 0000000000000001
[    0.174542] FS:  0000000000000000(0000) GS:ffff9d2808114000(0000) knlGS:0000000000000000
[    0.175684] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.176486] CR2: 000000000000001c CR3: 000000007264c001 CR4: 00000000000200b0
[    0.177483] Call Trace:
[    0.177828]  <TASK>
[    0.178123] mas_alloc_nodes (lib/maple_tree.c:176 (discriminator 2) lib/maple_tree.c:1255 (discriminator 2))
[    0.178692] mas_store_gfp (lib/maple_tree.c:5468)
[    0.179223] execmem_cache_add_locked (mm/execmem.c:207)
[    0.179870] execmem_alloc (mm/execmem.c:213 mm/execmem.c:313 mm/execmem.c:335 mm/execmem.c:475)
[    0.180397] ? ftrace_caller (arch/x86/kernel/ftrace_64.S:169)
[    0.180922] ? __pfx_ftrace_caller (arch/x86/kernel/ftrace_64.S:158)
[    0.181517] execmem_alloc_rw (mm/execmem.c:487)
[    0.182052] arch_ftrace_update_trampoline (arch/x86/kernel/ftrace.c:266 arch/x86/kernel/ftrace.c:344 arch/x86/kernel/ftrace.c:474)
[    0.182778] ? ftrace_caller_op_ptr (arch/x86/kernel/ftrace_64.S:182)
[    0.183388] ftrace_update_trampoline (kernel/trace/ftrace.c:7947)
[    0.184024] __register_ftrace_function (kernel/trace/ftrace.c:368)
[    0.184682] ftrace_startup (kernel/trace/ftrace.c:3048)
[    0.185205] ? __pfx_function_trace_call (kernel/trace/trace_functions.c:210)
[    0.185877] register_ftrace_function_nolock (kernel/trace/ftrace.c:8717)
[    0.186595] register_ftrace_function (kernel/trace/ftrace.c:8745)
[    0.187254] ? __pfx_function_trace_call (kernel/trace/trace_functions.c:210)
[    0.187924] function_trace_init (kernel/trace/trace_functions.c:170)
[    0.188499] tracing_set_tracer (kernel/trace/trace.c:5916 kernel/trace/trace.c:6349)
[    0.189088] register_tracer (kernel/trace/trace.c:2391)
[    0.189642] early_trace_init (kernel/trace/trace.c:11075 kernel/trace/trace.c:11149)
[    0.190204] start_kernel (init/main.c:970)
[    0.190732] x86_64_start_reservations (arch/x86/kernel/head64.c:307)
[    0.191381] x86_64_start_kernel (??:?)
[    0.191955] common_startup_64 (arch/x86/kernel/head_64.S:419)
[    0.192534]  </TASK>
[    0.192839] Modules linked in:
[    0.193267] CR2: 000000000000001c
[    0.193730] ---[ end trace 0000000000000000 ]---

The crash happens because on x86 ftrace allocations from execmem require
maple tree to be initialized.

Move maple tree initialization that depends only on slab availability
earlier in boot so that it will happen right after mm_core_init().

Link: https://lkml.kernel.org/r/20250824130759.1732736-1-rppt@kernel.org
Fixes: 5d79c2b ("x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reported-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Closes: https://lore.kernel.org/all/20250820184743.0302a8b5@gandalf.local.home/
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull bot pushed a commit that referenced this pull request Sep 11, 2025
…on memory

When I did memory failure tests, below panic occurs:

page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page))
kernel BUG at include/linux/page-flags.h:616!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40
RIP: 0010:unpoison_memory+0x2f3/0x590
RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246
RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0
RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb
R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000
R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe
FS:  00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unpoison_memory+0x2f3/0x590
 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110
 debugfs_attr_write+0x42/0x60
 full_proxy_write+0x5b/0x80
 vfs_write+0xd5/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xb9/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08f0314887
RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887
RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001
RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00
 </TASK>
Modules linked in: hwpoison_inject
---[ end trace 0000000000000000 ]---
RIP: 0010:unpoison_memory+0x2f3/0x590
RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246
RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0
RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb
R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000
R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe
FS:  00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
---[ end Kernel panic - not syncing: Fatal exception ]---

The root cause is that unpoison_memory() tries to check the PG_HWPoison
flags of an uninitialized page.  So VM_BUG_ON_PAGE(PagePoisoned(page)) is
triggered.  This can be reproduced by below steps:

1.Offline memory block:

 echo offline > /sys/devices/system/memory/memory12/state

2.Get offlined memory pfn:

 page-types -b n -rlN

3.Write pfn to unpoison-pfn

 echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn

This scenario can be identified by pfn_to_online_page() returning NULL. 
And ZONE_DEVICE pages are never expected, so we can simply fail if
pfn_to_online_page() == NULL to fix the bug.

Link: https://lkml.kernel.org/r/20250828024618.1744895-1-linmiaohe@huawei.com
Fixes: f1dd2cd ("mm, memory_hotplug: do not associate hotadded memory to zones until online")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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