Two bugs may lead to NULL dereference.

1. sys/pipe/pipe_dynamic.c
If malloc returns NULL on line 41, the variable m_pipe will be NULL, but the pointer to m_pipe->pipe is returned on line 46.

2. drivers/usbdev_mock/usbdev_mock.c
The variable res is checked on line 88 which indicates that it can be NULL, but the pointer to res->ep is returned on line 97.