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KCSAN: data-race in sem_lock / sem_lock

Status: auto-closed as invalid on 2020/12/01 09:40
Subsystems: kernel
[Documentation on labels]
First crash: 1276d, last: 1276d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in sem_lock / sem_lock (2) kernel 1 1031d 1031d 0/26 auto-closed as invalid on 2021/08/03 21:27

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

write to 0xffff88803c1cc0c0 of 4 bytes by task 15004 on cpu 1:
 complexmode_enter ipc/sem.c:339 [inline]
 sem_lock+0xb7/0x210 ipc/sem.c:397
 do_semtimedop+0x85d/0x1f40 ipc/sem.c:2082
 __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+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88803c1cc0c0 of 4 bytes by task 15003 on cpu 0:
 sem_lock+0x67/0x210 ipc/sem.c:415
 do_semtimedop+0x85d/0x1f40 ipc/sem.c:2082
 __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+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15003 Comm: syz-executor.0 Not tainted 5.10.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 15003 Comm: syz-executor.0 Not tainted 5.10.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x116/0x15d lib/dump_stack.c:118
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x46a/0x4d0 kernel/kcsan/core.c:568
 sem_lock+0x67/0x210 ipc/sem.c:415
 do_semtimedop+0x85d/0x1f40 ipc/sem.c:2082
 __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+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de59
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f72303fec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000041
RAX: ffffffffffffffda RBX: 0000000000027ec0 RCX: 000000000045de59
RDX: 0000000000000001 RSI: 0000000020000200 RDI: 0000000000000009
RBP: 000000000118c008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfd4
R13: 00007fffba404ddf R14: 00007f72303ff9c0 R15: 000000000118bfd4
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/27 09:35 upstream 41ba50b0572e 8b3eaf58 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.