diff options
| author | Hugh Dickins <hughd@google.com> | 2012-11-16 14:15:03 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-11-16 14:33:04 -0800 |
| commit | 215c02bc33bbd5ff4d7379a909462d11f0103218 (patch) | |
| tree | fa07d774e4b60404727ca0a8d54044d439eef905 /kernel/smp.c | |
| parent | 498c2280212327858e521e9d21345d4cc2637f54 (diff) | |
| download | linux-215c02bc33bbd5ff4d7379a909462d11f0103218.tar.bz2 | |
tmpfs: fix shmem_getpage_gfp() VM_BUG_ON
Fuzzing with trinity hit the "impossible" VM_BUG_ON(error) (which Fedora
has converted to WARNING) in shmem_getpage_gfp():
WARNING: at mm/shmem.c:1151 shmem_getpage_gfp+0xa5c/0xa70()
Pid: 29795, comm: trinity-child4 Not tainted 3.7.0-rc2+ #49
Call Trace:
warn_slowpath_common+0x7f/0xc0
warn_slowpath_null+0x1a/0x20
shmem_getpage_gfp+0xa5c/0xa70
shmem_fault+0x4f/0xa0
__do_fault+0x71/0x5c0
handle_pte_fault+0x97/0xae0
handle_mm_fault+0x289/0x350
__do_page_fault+0x18e/0x530
do_page_fault+0x2b/0x50
page_fault+0x28/0x30
tracesys+0xe1/0xe6
Thanks to Johannes for pointing to truncation: free_swap_and_cache()
only does a trylock on the page, so the page lock we've held since
before confirming swap is not enough to protect against truncation.
What cleanup is needed in this case? Just delete_from_swap_cache(),
which takes care of the memcg uncharge.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/smp.c')
0 files changed, 0 insertions, 0 deletions