mirror of https://github.com/torvalds/linux.git
740a5759bf
ashmem_mutex may create a chain of dependencies like:
CPU0 CPU1
mmap syscall ioctl syscall
-> mmap_sem (acquired) -> ashmem_ioctl
-> ashmem_mmap -> ashmem_mutex (acquired)
-> ashmem_mutex (try to acquire) -> copy_from_user
-> mmap_sem (try to acquire)
There is a lock odering problem between mmap_sem and ashmem_mutex causing
a lockdep splat[1] during a syzcaller test. This patch fixes the problem
by move copy_from_user out of ashmem_mutex.
[1] https://www.spinics.net/lists/kernel/msg2733200.html
Fixes:
|
||
|---|---|---|
| .. | ||
| ion | ||
| uapi | ||
| Kconfig | ||
| Makefile | ||
| TODO | ||
| ashmem.c | ||
| ashmem.h | ||