Various error info reported by gef #735
Description
- Did you use the latest version of GEF from
devbranch? - Is your bug specific to GEF (not GDB)? - Try to reproduce it running
gdb -nx - Did you read the documentation first?
- Did you check issues (including
the closed ones) - and the PR?
Step 1: Describe your environment
- Operating System / Distribution: ArchLinux w/ Glibc 2.33
- Architecture: x86_64
- GEF version (including the Python library version) run
versionin GEF.
GEF: rev:5baa1280dcc0057b041a184d4164c5547125fac9 (Git - clean)
SHA1(/home/tjm/.config/gef/repo/gef.py): 26ae828dbe4c01f5dc70959522c55317d4476215
GDB: 11.1
GDB-Python: 3.9
Step 2: Describe your problem
Steps to reproduce
- Compile
poc.cfrom the minimalist test case to get the binarypoc - Load binary
pocwith gef - Set a breakpoint at the return statement with command
b 4 - Run the program with
rcommand
Minimalist test case
// compile with gcc -fPIE -fpic -O0 -g -o poc poc.c
int main() {
const char *grid[] = {" \\ \\"," / ","/\\ \\\\","//\\/\\","\\/\\//"};
(void *)(grid);
return 0;
}Observed Results
- gef prints an error message
Error while writing index for /tmp/poc: mkstemp: No such file or directory.in step 2 - gef prints the following error message of invalid escape sequence in step 4:
/home/tjm/.config/gef/repo/gef.py:2768: DeprecationWarning: invalid escape sequence '\/'
res = gdb.Value(address).cast(char_ptr).string(encoding=encoding, length=length).strip()
/home/tjm/.config/gef/repo/gef.py:2768: DeprecationWarning: invalid escape sequence '\ '
res = gdb.Value(address).cast(char_ptr).string(encoding=encoding, length=length).strip()
Expected results
- No errors reported
Traces
gef➤ r
Starting program: /tmp/poc
Breakpoint 1, main () at poc.c:4
4 return 0;
[ Legend: Modified register | Code | Heap | Stack | String ]
───────────────────────────────────────────────────────────────────────────────────── registers ────
/home/tjm/.config/gef/repo/gef.py:2768: DeprecationWarning: invalid escape sequence '\/'
res = gdb.Value(address).cast(char_ptr).string(encoding=encoding, length=length).strip()
$rax : 0x000055555555601c → 0x0000002f2f5c2f5c ("\/\//"?)
$rbx : 0x00005555555551b0 → <__libc_csu_init+0> endbr64
$rcx : 0x00007ffff7f7c598 → 0x00007ffff7f7e960 → 0x0000000000000000
$rdx : 0x00007fffffffe5d8 → 0x00007fffffffe93e → "SHELL=/bin/bash"
/home/tjm/.config/gef/repo/gef.py:2768: DeprecationWarning: invalid escape sequence '\ '
res = gdb.Value(address).cast(char_ptr).string(encoding=encoding, length=length).strip()
$rsp : 0x00007fffffffe4a0 → 0x0000555555556004 → 0x2020005c205c2020 ("\ \"?)
$rbp : 0x00007fffffffe4d0 → 0x0000000000000000
$rsi : 0x00007fffffffe5c8 → 0x00007fffffffe935 → "/tmp/poc"
$rdi : 0x1
$rip : 0x0000555555555187 → <main+78> mov eax, 0x0
$r8 : 0x0
$r9 : 0x00007ffff7fdcfd0 → <_dl_fini+0> endbr64
$r10 : 0x00007ffff7dcb798 → 0x0010001200002ab7
$r11 : 0x202
$r12 : 0x0000555555555040 → <_start+0> endbr64
$r13 : 0x0
$r14 : 0x0
$r15 : 0x0
$eflags: [ZERO carry PARITY adjust sign trap INTERRUPT direction overflow resume virtualx86 identification]
$cs: 0x0033 $ss: 0x002b $ds: 0x0000 $es: 0x0000 $fs: 0x0000 $gs: 0x0000
───────────────────────────────────────────────────────────────────────────────────────── stack ────
0x00007fffffffe4a0│+0x0000: 0x0000555555556004 → 0x2020005c205c2020 ("\ \"?) ← $rsp
0x00007fffffffe4a8│+0x0008: 0x000055555555600a → 0x5c2f0020202f2020 ("/ "?)
0x00007fffffffe4b0│+0x0010: 0x0000555555556010 → 0x2f2f005c5c205c2f ("/\ \"?)
0x00007fffffffe4b8│+0x0018: 0x0000555555556016 → 0x2f5c005c2f5c2f2f ("//\/\"?)
0x00007fffffffe4c0│+0x0020: 0x000055555555601c → 0x0000002f2f5c2f5c ("\/\//"?)
0x00007fffffffe4c8│+0x0028: 0x20e2374cce9c1b00
0x00007fffffffe4d0│+0x0030: 0x0000000000000000 ← $rbp
0x00007fffffffe4d8│+0x0038: 0x00007ffff7de3b25 → <__libc_start_main+213> mov edi, eax
─────────────────────────────────────────────────────────────────────────────────── code:x86:64 ────
0x555555555178 <main+63> mov QWORD PTR [rbp-0x18], rax
0x55555555517c <main+67> lea rax, [rip+0xe99] # 0x55555555601c
0x555555555183 <main+74> mov QWORD PTR [rbp-0x10], rax
→ 0x555555555187 <main+78> mov eax, 0x0
0x55555555518c <main+83> mov rdx, QWORD PTR [rbp-0x8]
0x555555555190 <main+87> sub rdx, QWORD PTR fs:0x28
0x555555555199 <main+96> je 0x5555555551a0 <main+103>
0x55555555519b <main+98> call 0x555555555030 <__stack_chk_fail@plt>
0x5555555551a0 <main+103> leave
──────────────────────────────────────────────────────────────────────────────── source:poc.c+4 ────
1 int main() {
2 const char *grid[] = {" \\ \\"," / ","/\\ \\\\","//\\/\\","\\/\\//"};
3 (void *)(grid);
●→ 4 return 0;
5 }
─────────────────────────────────────────────────────────────────────────────────────── threads ────
[#0] Id 1, Name: "poc", stopped 0x555555555187 in main (), reason: BREAKPOINT
───────────────────────────────────────────────────────────────────────────────────────── trace ────
[#0] 0x555555555187 → main()
────────────────────────────────────────────────────────────────────────────────────────────────────
gef➤