syzbot


KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (3)

Status: auto-closed as invalid on 2020/06/18 14:03
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 903d, last: 845d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (4) 3 744d 776d 0/23 auto-closed as invalid on 2020/08/28 22:57
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (2) 2 976d 977d 0/23 auto-closed as invalid on 2020/02/14 17:46
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me 1 1005d 1005d 0/23 closed as invalid on 2019/11/19 13:54
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (5) 1 653d 653d 0/23 auto-closed as invalid on 2020/11/28 10:56
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (6) 1 599d 599d 0/23 auto-closed as invalid on 2021/01/21 10:32
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (7) 1 458d 458d 0/23 auto-closed as invalid on 2021/06/11 04:30

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

write to 0xffff8881174ed0a4 of 4 bytes by task 15417 on cpu 0:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 futex_wait_queue_me+0x19e/0x290 kernel/futex.c:2631
 futex_wait_requeue_pi.constprop.0+0x283/0xa60 kernel/futex.c:3278
 do_futex+0x1c9/0x15b0 kernel/futex.c:3828
 __do_sys_futex kernel/futex.c:3869 [inline]
 __se_sys_futex kernel/futex.c:3837 [inline]
 __x64_sys_futex+0x2dc/0x410 kernel/futex.c:3837
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881174ed0a4 of 4 bytes by task 15423 on cpu 1:
 attach_to_pi_owner+0x7f/0x560 kernel/futex.c:1233
 lookup_pi_state kernel/futex.c:1320 [inline]
 futex_requeue+0xdfb/0x1050 kernel/futex.c:2077
 do_futex+0x2e6/0x15b0 kernel/futex.c:3831
 __do_sys_futex kernel/futex.c:3869 [inline]
 __se_sys_futex kernel/futex.c:3837 [inline]
 __x64_sys_futex+0x2dc/0x410 kernel/futex.c:3837
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15423 Comm: syz-executor.5 Not tainted 5.7.0-rc1-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 2020/04/15 18:14 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3f3c5574 .config log report
ci2-upstream-kcsan-gce 2020/03/06 05:28 https://github.com/google/ktsan.git kcsan 766d004d1b85 b655d91b .config log report
ci2-upstream-kcsan-gce 2020/02/17 01:06 https://github.com/google/ktsan.git kcsan b12d66a6c34f 1f448cd6 .config log report