KCSAN: data-race in sem_lock / sem

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in sem_lock / sem_lock kernel				1	1554d	1554d	0/28	auto-closed as invalid on 2020/12/01 09:40

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BUG: KCSAN: data-race in sem_lock / sem_lock

write to 0xffff88812e7100c0 of 4 bytes by task 11504 on cpu 1:
 complexmode_enter ipc/sem.c:339 [inline]
 sem_lock+0xb7/0x270 ipc/sem.c:397
 do_semtimedop+0x785/0x19c0 ipc/sem.c:2084
 __do_sys_semop ipc/sem.c:2279 [inline]
 __se_sys_semop ipc/sem.c:2276 [inline]
 __x64_sys_semop+0x3f/0x50 ipc/sem.c:2276
 do_syscall_64+0x44/0x80 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812e7100c0 of 4 bytes by task 11473 on cpu 0:
 sem_lock+0x67/0x270 ipc/sem.c:415
 do_semtimedop+0x785/0x19c0 ipc/sem.c:2084
 __do_sys_semop ipc/sem.c:2279 [inline]
 __se_sys_semop ipc/sem.c:2276 [inline]
 __x64_sys_semop+0x3f/0x50 ipc/sem.c:2276
 do_syscall_64+0x44/0x80 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000009 -> 0x0000000a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11473 Comm: syz-executor.2 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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