syzbot


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

Status: auto-closed as invalid on 2021/06/19 09:40
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 511d, last: 455d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_exit / futex_wait_queue_me (2) 1 684d 684d 0/23 auto-closed as invalid on 2020/11/02 08:53
upstream KCSAN: data-race in do_exit / futex_wait_queue_me (3) 3 586d 614d 0/23 auto-closed as invalid on 2021/02/08 21:09
upstream KCSAN: data-race in do_exit / futex_wait_queue_me 3 745d 775d 0/23 auto-closed as invalid on 2020/09/02 20:47

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

write to 0xffff88814862906c of 4 bytes by task 5042 on cpu 1:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 futex_wait_queue_me+0x1ba/0x260 kernel/futex.c:2606
 futex_wait+0x143/0x430 kernel/futex.c:2708
 do_futex+0x9d8/0x1ee0 kernel/futex.c:3732
 __do_sys_futex kernel/futex.c:3805 [inline]
 __se_sys_futex+0x21c/0x380 kernel/futex.c:3786
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3786
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88814862906c of 4 bytes by task 5043 on cpu 0:
 find_alive_thread kernel/exit.c:512 [inline]
 find_new_reaper kernel/exit.c:561 [inline]
 forget_original_parent kernel/exit.c:636 [inline]
 exit_notify kernel/exit.c:669 [inline]
 do_exit+0x56c/0x1560 kernel/exit.c:846
 do_group_exit+0xce/0x1a0 kernel/exit.c:923
 get_signal+0xfc3/0x1610 kernel/signal.c:2818
 arch_do_signal_or_restart+0x2a/0x220 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5043 Comm: syz-executor.2 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/05/15 09:31 upstream 25a1298726e9 8bdd5343 .config log report info KCSAN: data-race in do_exit / futex_wait_queue_me
ci2-upstream-kcsan-gce 2021/05/07 05:19 upstream e48661230cc3 06585184 .config log report info KCSAN: data-race in do_exit / futex_wait_queue_me
ci2-upstream-kcsan-gce 2021/04/26 23:29 upstream 9f4ad9e425a1 8ee2dea6 .config log report info KCSAN: data-race in do_exit / futex_wait_queue_me
ci2-upstream-kcsan-gce 2021/04/14 11:10 upstream 50987beca096 3134b37f .config log report info KCSAN: data-race in do_exit / futex_wait_queue_me
ci2-upstream-kcsan-gce 2021/03/20 10:02 upstream 1c273e10bc0c e45f5621 .config log report info KCSAN: data-race in do_exit / futex_wait_queue_me