KCSAN: data-race in munlock_vma_pages_range / try_to_unmap

KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one
Status: auto-closed as invalid on 2020/03/10 21:44
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 632d, last: 632d

similar bugs (6):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (6)	2	245d	268d	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	371d	387d	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	431d	450d	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	334d	334d	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 (7)	3	128d	143d	0/22	auto-closed as invalid on 2021/06/22 19:33
upstream	KCSAN: data-race in munlock_vma_pages_range / try_to_unmap_one (2)	1	547d	547d	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 0xffff8880a7afe500 of 8 bytes by task 18773 on cpu 1:
 munlock_vma_pages_range+0x59/0x790 mm/mlock.c:448
 munlock_vma_pages_all mm/internal.h:306 [inline]
 exit_mmap+0x24f/0x300 mm/mmap.c:3124
 __mmput kernel/fork.c:1082 [inline]
 mmput+0xea/0x280 kernel/fork.c:1103
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x4ac/0x18c0 kernel/exit.c:784
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a7afe500 of 8 bytes by task 18724 on cpu 0:
 try_to_unmap_one+0x105/0x16f0 mm/rmap.c:1382
 rmap_walk_file+0x23c/0x590 mm/rmap.c:1920
 rmap_walk+0x118/0x190 mm/rmap.c:1938
 try_to_munlock+0x8b/0xb0 mm/rmap.c:1789
 __munlock_isolated_page+0x89/0x1a0 mm/mlock.c:138
 __munlock_pagevec+0x392/0x7a0 mm/mlock.c:346
 munlock_vma_pages_range+0x5cc/0x790 mm/mlock.c:499
 munlock_vma_pages_all mm/internal.h:306 [inline]
 exit_mmap+0x24f/0x300 mm/mmap.c:3124
 __mmput kernel/fork.c:1082 [inline]
 mmput+0xea/0x280 kernel/fork.c:1103
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x4ac/0x18c0 kernel/exit.c:784
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18724 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2019/12/31 21:42	https://github.com/google/ktsan.git kcsan	245a43005292	25a0186e	.config	log	report