syzbot


KCSAN: data-race in find_alive_thread / get_signal

Status: closed as invalid on 2020/06/18 14:24
Subsystems: kernel
[Documentation on labels]
First crash: 1618d, last: 1386d

Sample crash report:
XFS (nullb0): Invalid superblock magic number
==================================================================
BUG: KCSAN: data-race in find_alive_thread / get_signal

write to 0xffff8880ab8c4064 of 4 bytes by task 724 on cpu 0:
 get_signal+0x7a2/0x1290 kernel/signal.c:2719
 do_signal+0x2b/0x840 arch/x86/kernel/signal.c:784
 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:161
 prepare_exit_to_usermode+0x194/0x1e0 arch/x86/entry/common.c:196
 swapgs_restore_regs_and_return_to_usermode+0x0/0x40

read to 0xffff8880ab8c4064 of 4 bytes by task 716 on cpu 1:
 find_alive_thread+0xd5/0x120 kernel/exit.c:489
 find_new_reaper kernel/exit.c:538 [inline]
 forget_original_parent+0xef/0x980 kernel/exit.c:613
 exit_notify kernel/exit.c:646 [inline]
 do_exit+0x75c/0x11e0 kernel/exit.c:816
 do_group_exit+0xae/0x1a0 kernel/exit.c:893
 __do_sys_exit_group kernel/exit.c:904 [inline]
 __se_sys_exit_group kernel/exit.c:902 [inline]
 __x64_sys_exit_group+0x2b/0x30 kernel/exit.c:902
 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: 716 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (26):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/11 03:36 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3ab7a05a .config console log report ci2-upstream-kcsan-gce
2020/05/22 21:52 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4afdfa20 .config console log report ci2-upstream-kcsan-gce
2020/05/06 07:24 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 35b8eb30 .config console log report ci2-upstream-kcsan-gce
2020/05/04 03:42 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 58ae5e18 .config console log report ci2-upstream-kcsan-gce
2020/04/29 11:35 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 ba2806db .config console log report ci2-upstream-kcsan-gce
2020/04/20 02:27 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9f7c6d12 .config console log report ci2-upstream-kcsan-gce
2020/04/07 13:44 https://github.com/google/ktsan.git kcsan 40959e34d670 99a96044 .config console log report ci2-upstream-kcsan-gce
2020/03/29 04:23 https://github.com/google/ktsan.git kcsan 40959e34d670 05736b29 .config console log report ci2-upstream-kcsan-gce
2020/02/28 04:25 https://github.com/google/ktsan.git kcsan 766d004d1b85 c88c7b75 .config console log report ci2-upstream-kcsan-gce
2020/02/08 04:32 https://github.com/google/ktsan.git kcsan 6cccb8ba35bd 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/01/23 03:01 https://github.com/google/ktsan.git kcsan 245a43005292 3334d684 .config console log report ci2-upstream-kcsan-gce
2020/01/10 10:32 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/08 16:14 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config console log report ci2-upstream-kcsan-gce
2020/01/05 15:24 https://github.com/google/ktsan.git kcsan 245a43005292 d646e21f .config console log report ci2-upstream-kcsan-gce
2019/12/20 20:06 https://github.com/google/ktsan.git kcsan 245a43005292 34011c05 .config console log report ci2-upstream-kcsan-gce
2019/12/19 16:52 https://github.com/google/ktsan.git kcsan 245a43005292 36650b4b .config console log report ci2-upstream-kcsan-gce
2019/12/16 15:04 https://github.com/google/ktsan.git kcsan 245a43005292 0ae38e44 .config console log report ci2-upstream-kcsan-gce
2019/12/12 09:15 https://github.com/google/ktsan.git kcsan ef798c30ba4e d973f528 .config console log report ci2-upstream-kcsan-gce
2019/12/10 10:37 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4b83c8fb .config console log report ci2-upstream-kcsan-gce
2019/12/03 22:32 https://github.com/google/ktsan.git kcsan ef798c30ba4e 0ecb9746 .config console log report ci2-upstream-kcsan-gce
2019/11/21 03:39 https://github.com/google/ktsan.git kcsan 5863cc791e4c 8098ea0f .config console log report ci2-upstream-kcsan-gce
2019/11/12 17:53 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
2019/11/06 21:03 https://github.com/google/ktsan.git kcsan 94c006602e13 da505f84 .config console log report ci2-upstream-kcsan-gce
2019/11/04 18:56 https://github.com/google/ktsan.git kcsan 94c006602e13 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/10/25 15:57 https://github.com/google/ktsan.git kcsan 05f2236801fe 04ca72cd .config console log report ci2-upstream-kcsan-gce
2019/10/23 03:59 https://github.com/google/ktsan.git kcsan 05f2236801fe d0686497 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.