syzbot


KCSAN: data-race in smpboot_thread_fn / watchdog

Status: closed as invalid on 2020/06/18 14:24
Subsystems: kasan
[Documentation on labels]
First crash: 1646d, last: 1437d

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

write to 0xffff88812b7b6090 of 8 bytes by task 16 on cpu 1:
 smpboot_thread_fn+0x325/0x4a0 kernel/smpboot.c:163
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff88812b7b6090 of 8 bytes by task 1928 on cpu 0:
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2b8/0x960 kernel/hung_task.c:289
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1928 Comm: khungtaskd Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 1928 Comm: khungtaskd Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x11d/0x187 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x1a kernel/kcsan/report.c:626
 kcsan_setup_watchpoint+0x3fb/0x440 kernel/kcsan/core.c:519
 check_hung_uninterruptible_tasks kernel/hung_task.c:197 [inline]
 watchdog+0x2b8/0x960 kernel/hung_task.c:289
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (30):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/19 21:38 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6d882fd2 .config console log report ci2-upstream-kcsan-gce
2020/04/25 14:26 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a113ba38 .config console log report ci2-upstream-kcsan-gce
2020/04/19 12:58 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6dfd45e1 .config console log report ci2-upstream-kcsan-gce
2020/04/14 11:35 https://github.com/google/ktsan.git kcsan 40959e34d670 3f3c5574 .config console log report ci2-upstream-kcsan-gce
2020/04/02 21:44 https://github.com/google/ktsan.git kcsan 40959e34d670 a34e2c33 .config console log report ci2-upstream-kcsan-gce
2020/03/13 16:34 https://github.com/google/ktsan.git kcsan 941e0d917bbf fd69032d .config console log report ci2-upstream-kcsan-gce
2020/02/25 21:40 https://github.com/google/ktsan.git kcsan 766d004d1b85 4c886d6a .config console log report ci2-upstream-kcsan-gce
2020/02/22 04:34 https://github.com/google/ktsan.git kcsan 766d004d1b85 2ffa6679 .config console log report ci2-upstream-kcsan-gce
2020/02/16 14:58 https://github.com/google/ktsan.git kcsan b12d66a6c34f cf914200 .config console log report ci2-upstream-kcsan-gce
2020/02/14 02:33 https://github.com/google/ktsan.git kcsan b12d66a6c34f 5d7b90f1 .config console log report ci2-upstream-kcsan-gce
2020/02/09 03:31 https://github.com/google/ktsan.git kcsan f60f0f543333 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/01/28 09:27 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config console log report ci2-upstream-kcsan-gce
2020/01/26 13:03 https://github.com/google/ktsan.git kcsan 245a43005292 f4e7270e .config console log report ci2-upstream-kcsan-gce
2020/01/23 22:51 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config console log report ci2-upstream-kcsan-gce
2020/01/16 12:12 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/10 03:14 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/08 22:08 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config console log report ci2-upstream-kcsan-gce
2020/01/06 06:16 https://github.com/google/ktsan.git kcsan 245a43005292 438e1227 .config console log report ci2-upstream-kcsan-gce
2019/12/22 02:34 https://github.com/google/ktsan.git kcsan 245a43005292 bc586918 .config console log report ci2-upstream-kcsan-gce
2019/12/17 20:16 https://github.com/google/ktsan.git kcsan 245a43005292 1af3875f .config console log report ci2-upstream-kcsan-gce
2019/12/13 07:48 https://github.com/google/ktsan.git kcsan 245a43005292 2a752b7c .config console log report ci2-upstream-kcsan-gce
2019/12/13 03:08 https://github.com/google/ktsan.git kcsan 245a43005292 08003f64 .config console log report ci2-upstream-kcsan-gce
2019/12/10 05:08 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4b83c8fb .config console log report ci2-upstream-kcsan-gce
2019/12/05 05:27 https://github.com/google/ktsan.git kcsan ef798c30ba4e b2088328 .config console log report ci2-upstream-kcsan-gce
2019/12/02 01:13 https://github.com/google/ktsan.git kcsan ef798c30ba4e f879db37 .config console log report ci2-upstream-kcsan-gce
2019/11/21 02:34 https://github.com/google/ktsan.git kcsan 5863cc791e4c 8098ea0f .config console log report ci2-upstream-kcsan-gce
2019/11/12 18:02 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
2019/10/26 00:41 https://github.com/google/ktsan.git kcsan 05f2236801fe 413926c5 .config console log report ci2-upstream-kcsan-gce
2019/10/24 22:35 https://github.com/google/ktsan.git kcsan 05f2236801fe d01bb02a .config console log report ci2-upstream-kcsan-gce
2019/10/23 19:42 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.