syzbot


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

Status: auto-closed as invalid on 2022/07/27 14:33
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 159d, last: 159d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in acct_collect / do_exit (3) 34 390d 623d 0/24 auto-closed as invalid on 2021/12/08 08:08
upstream KCSAN: data-race in acct_collect / do_exit (2) 4 708d 721d 0/24 auto-closed as invalid on 2021/01/24 15:31
upstream KCSAN: data-race in acct_collect / do_exit 1 843d 843d 0/24 auto-closed as invalid on 2020/09/11 14:08

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

write to 0xffff888107dfa61c of 4 bytes by task 15558 on cpu 1:
 reparent_leader kernel/exit.c:609 [inline]
 forget_original_parent kernel/exit.c:661 [inline]
 exit_notify kernel/exit.c:677 [inline]
 do_exit+0xabe/0x1720 kernel/exit.c:815
 do_group_exit+0xa5/0x160 kernel/exit.c:925
 get_signal+0xf54/0x1020 kernel/signal.c:2857
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff888107dfa61c of 4 bytes by task 15588 on cpu 0:
 thread_group_leader include/linux/sched/signal.h:711 [inline]
 acct_collect+0x16a/0x3c0 kernel/acct.c:572
 do_exit+0x4cd/0x1720 kernel/exit.c:774
 do_group_exit+0xa5/0x160 kernel/exit.c:925
 get_signal+0xf54/0x1020 kernel/signal.c:2857
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare+0x69/0x90 kernel/entry/common.c:201
 irqentry_exit_to_user_mode+0x5/0x10 kernel/entry/common.c:307
 irqentry_exit+0xe/0x40 kernel/entry/common.c:408
 asm_exc_page_fault+0x27/0x30

value changed: 0x00000000 -> 0x00000011

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15588 Comm: syz-executor.1 Not tainted 5.19.0-rc3-syzkaller-00038-gca1fdab7fd27-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/06/22 14:22 upstream ca1fdab7fd27 0fc5c330 .config log report info KCSAN: data-race in acct_collect / do_exit
* Struck through repros no longer work on HEAD.