syzbot


KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (7)
Status: auto-closed as invalid on 2021/06/22 19:33
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 387d, last: 372d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one 1 876d 876d 0/22 auto-closed as invalid on 2020/03/10 21:44
upstream KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (6) 2 490d 513d 0/22 auto-closed as invalid on 2021/02/24 23:17
upstream KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (4) 2 615d 631d 0/22 auto-closed as invalid on 2020/10/22 10:22
upstream KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (3) 2 675d 694d 0/22 auto-closed as invalid on 2020/08/23 10:47
upstream KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (5) 1 578d 578d 0/22 auto-closed as invalid on 2020/11/28 11:46
upstream KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (2) 1 791d 791d 0/22 auto-closed as invalid on 2020/06/03 05:11

Sample crash report:
==================================================================
BUG: KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one

write to 0xffff888132b25e90 of 8 bytes by task 28850 on cpu 0:
 munlock_vma_pages_range+0x52/0x430 mm/mlock.c:423
 munlock_vma_pages_all mm/internal.h:367 [inline]
 exit_mmap+0x128/0x400 mm/mmap.c:3192
 __mmput+0x27/0x1c0 kernel/fork.c:1096
 mmput+0x3d/0x50 kernel/fork.c:1117
 exit_mm+0x360/0x450 kernel/exit.c:502
 do_exit+0x3ff/0x1560 kernel/exit.c:813
 do_group_exit+0xce/0x1a0 kernel/exit.c:923
 get_signal+0xfc3/0x1610 kernel/signal.c:2818
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888132b25e90 of 8 bytes by task 28899 on cpu 1:
 try_to_unmap_one+0xb2/0x1320 mm/rmap.c:1409
 rmap_walk_file+0x1f9/0x300 mm/rmap.c:1936
 rmap_walk mm/rmap.c:1954 [inline]
 try_to_munlock+0x8f/0xd0 mm/rmap.c:1805
 __munlock_isolated_page mm/mlock.c:121 [inline]
 __munlock_pagevec+0x95d/0xb50 mm/mlock.c:321
 munlock_vma_pages_range+0x3d8/0x430 mm/mlock.c:474
 munlock_vma_pages_all mm/internal.h:367 [inline]
 exit_mmap+0x128/0x400 mm/mmap.c:3192
 __mmput+0x27/0x1c0 kernel/fork.c:1096
 mmput+0x3d/0x50 kernel/fork.c:1117
 exit_mm+0x360/0x450 kernel/exit.c:502
 do_exit+0x3ff/0x1560 kernel/exit.c:813
 do_group_exit+0xce/0x1a0 kernel/exit.c:923
 get_signal+0xfc3/0x1610 kernel/signal.c:2818
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 28899 Comm: syz-executor.5 Not tainted 5.13.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/05/18 19:29 upstream 8ac91e6c6033 a343ba6b .config log report info KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one
ci2-upstream-kcsan-gce 2021/05/06 15:04 upstream 8404c9fbc84b 06585184 .config log report info KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one
ci2-upstream-kcsan-gce 2021/05/03 04:48 upstream 9ccce092fc64 77e2b668 .config log report info KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one