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| author |   Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2019-11-30 17:50:26 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-01 06:29:18 -0800 |
| commit | 8897c1b1a1795cab23d5ac13e4e23bf0b5f4e0c6 (patch) | |
| tree | 9d83e84a17bcf0d7e1d9e17550e02fbe956776b2 /mm/memory.c | |
| parent | mm: drop mmap_sem before calling balance_dirty_pages() in write fault (diff) | |
| download | linux-dev-8897c1b1a1795cab23d5ac13e4e23bf0b5f4e0c6.tar.xz linux-dev-8897c1b1a1795cab23d5ac13e4e23bf0b5f4e0c6.zip | |
shmem: pin the file in shmem_fault() if mmap_sem is dropped
syzbot found the following crash:
BUG: KASAN: use-after-free in perf_trace_lock_acquire+0x401/0x530 include/trace/events/lock.h:13
Read of size 8 at addr ffff8880a5cf2c50 by task syz-executor.0/26173
CPU: 0 PID: 26173 Comm: syz-executor.0 Not tainted 5.3.0-rc6 #146
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
perf_trace_lock_acquire+0x401/0x530 include/trace/events/lock.h:13
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x2de/0x410 kernel/locking/lockdep.c:4411
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
shmem_fault+0x5ec/0x7b0 mm/shmem.c:2034
__do_fault+0x111/0x540 mm/memory.c:3083
do_shared_fault mm/memory.c:3535 [inline]
do_fault mm/memory.c:3613 [inline]
handle_pte_fault mm/memory.c:3840 [inline]
__handle_mm_fault+0x2adf/0x3f20 mm/memory.c:3964
handle_mm_fault+0x1b5/0x6b0 mm/memory.c:4001
do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
__do_page_fault+0x536/0xdd0 arch/x86/mm/fault.c:1506
do_page_fault+0x38/0x590 arch/x86/mm/fault.c:1530
page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1202
It happens if the VMA got unmapped under us while we dropped mmap_sem
and inode got freed.
Pinning the file if we drop mmap_sem fixes the issue.
Link: http://lkml.kernel.org/r/20190927083908.rhifa4mmaxefc24r@box
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+03ee87124ee05af991bd@syzkaller.appspotmail.com
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions