syzbot


KCSAN: data-race in do_exit / do_exit

Status: auto-closed as invalid on 2022/06/11 22:15
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 216d, last: 209d

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

write to 0xffffffff85a4f880 of 4 bytes by task 2819 on cpu 1:
 check_stack_usage kernel/exit.c:728 [inline]
 do_exit+0x1177/0x1720 kernel/exit.c:839
 do_group_exit+0xa5/0x160 kernel/exit.c:925
 get_signal+0xf54/0x1020 kernel/signal.c:2864
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:867
 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+0x44/0xae

read to 0xffffffff85a4f880 of 4 bytes by task 2823 on cpu 0:
 check_stack_usage kernel/exit.c:721 [inline]
 do_exit+0x10e7/0x1720 kernel/exit.c:839
 do_group_exit+0xa5/0x160 kernel/exit.c:925
 get_signal+0xf54/0x1020 kernel/signal.c:2864
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:867
 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+0x44/0xae

value changed: 0x00002c30 -> 0x00002a50

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2823 Comm: syz-executor.4 Not tainted 5.18.0-rc5-syzkaller-00178-g30c8e80f7932-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/07 22:14 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in do_exit / do_exit
ci2-upstream-kcsan-gce 2022/05/01 00:54 upstream 57ae8a492116 2df221f6 .config log report info KCSAN: data-race in do_exit / do_exit
* Struck through repros no longer work on HEAD.