syzbot


KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (4)

Status: auto-closed as invalid on 2020/08/28 22:57
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 828d, last: 797d
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 (2) 2 1028d 1029d 0/24 auto-closed as invalid on 2020/02/14 17:46
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me 1 1058d 1058d 0/24 closed as invalid on 2019/11/19 13:54
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (3) 3 897d 956d 0/24 auto-closed as invalid on 2020/06/18 14:03
upstream KCSAN: data-race in attach_to_pi_owner / futex_wait_queue_me (5) 1 706d 706d 0/24 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 652d 652d 0/24 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 511d 511d 0/24 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 0xffff8880b615c0a4 of 4 bytes by task 14127 on cpu 0:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 futex_wait_queue_me+0x1a8/0x250 kernel/futex.c:2634
 futex_wait_requeue_pi kernel/futex.c:3281 [inline]
 do_futex+0x1807/0x21c0 kernel/futex.c:3831
 __do_sys_futex kernel/futex.c:3872 [inline]
 __se_sys_futex+0x26d/0x330 kernel/futex.c:3840
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3840
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b615c0a4 of 4 bytes by task 14135 on cpu 1:
 attach_to_pi_owner+0x64/0x4c0 kernel/futex.c:1236
 lookup_pi_state kernel/futex.c:1323 [inline]
 futex_requeue+0xb74/0x1520 kernel/futex.c:2080
 do_futex+0x153c/0x21c0 kernel/futex.c:3834
 __do_sys_futex kernel/futex.c:3872 [inline]
 __se_sys_futex+0x26d/0x330 kernel/futex.c:3840
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3840
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14135 Comm: syz-executor.2 Not tainted 5.8.0-rc6-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 2020/07/24 22:51 upstream 68845a55c31b 0a13649c .config log report
ci2-upstream-kcsan-gce 2020/06/24 14:44 upstream 3e08a95294a4 41694dbf .config log report
ci2-upstream-kcsan-gce 2020/06/23 14:36 upstream dd0d718152e4 54566aff .config log report
* Struck through repros no longer work on HEAD.