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KCSAN: data-race in sem_lock / sem_unlock

Status: auto-closed as invalid on 2021/05/28 19:52
Subsystems: kernel
[Documentation on labels]
First crash: 1098d, last: 1098d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in sem_lock / sem_unlock

write to 0xffff88812af15cc0 of 4 bytes by task 7622 on cpu 0:
 complexmode_tryleave ipc/sem.c:374 [inline]
 sem_unlock+0x266/0x280 ipc/sem.c:461
 do_semtimedop+0xde0/0x19c0 ipc/sem.c:2172
 __do_sys_semop ipc/sem.c:2277 [inline]
 __se_sys_semop ipc/sem.c:2274 [inline]
 __x64_sys_semop+0x3f/0x50 ipc/sem.c:2274
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812af15cc0 of 4 bytes by task 7594 on cpu 1:
 sem_lock+0x67/0x270 ipc/sem.c:415
 do_semtimedop+0x785/0x19c0 ipc/sem.c:2082
 ksys_semtimedop ipc/sem.c:2241 [inline]
 __do_sys_semtimedop ipc/sem.c:2249 [inline]
 __se_sys_semtimedop ipc/sem.c:2246 [inline]
 __x64_sys_semtimedop+0xb0/0xd0 ipc/sem.c:2246
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7594 Comm: syz-executor.5 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/04/23 19:48 upstream 18a3c5f7abfd 17f0b706 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in sem_lock / sem_unlock
* Struck through repros no longer work on HEAD.