syzbot


KCSAN: data-race in taskstats_exit / taskstats_exit

Status: fixed on 2020/02/14 01:19
Reported-by: syzbot+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com
Fix commit: 0b8d616fb5a8 taskstats: fix data-race
First crash: 1150d, last: 1018d

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

write to 0xffff88811ff1d110 of 8 bytes by task 11725 on cpu 1:
 taskstats_tgid_alloc kernel/taskstats.c:567 [inline]
 taskstats_exit+0x6b7/0x720 kernel/taskstats.c:596
 do_exit+0x281/0x18c0 kernel/exit.c:782
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811ff1d110 of 8 bytes by task 11722 on cpu 0:
 taskstats_tgid_alloc kernel/taskstats.c:559 [inline]
 taskstats_exit+0xb2/0x720 kernel/taskstats.c:596
 do_exit+0x281/0x18c0 kernel/exit.c:782
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:904
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11722 Comm: syz-executor.1 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (157):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/02/13 12:37 https://github.com/google/ktsan.git kcsan f60f0f543333 e6247653 .config log report
ci2-upstream-kcsan-gce 2020/02/12 17:17 https://github.com/google/ktsan.git kcsan f60f0f543333 84f4fc8a .config log report
ci2-upstream-kcsan-gce 2020/02/12 05:27 https://github.com/google/ktsan.git kcsan f60f0f543333 a75b198c .config log report
ci2-upstream-kcsan-gce 2020/02/11 17:40 https://github.com/google/ktsan.git kcsan f60f0f543333 4d1ab643 .config log report
ci2-upstream-kcsan-gce 2020/02/11 08:01 https://github.com/google/ktsan.git kcsan f60f0f543333 084454ae .config log report
ci2-upstream-kcsan-gce 2020/02/10 19:10 https://github.com/google/ktsan.git kcsan f60f0f543333 d9e55b05 .config log report
ci2-upstream-kcsan-gce 2020/02/10 15:48 https://github.com/google/ktsan.git kcsan f60f0f543333 18847f55 .config log report
ci2-upstream-kcsan-gce 2020/02/09 22:06 https://github.com/google/ktsan.git kcsan f60f0f543333 35f5e45e .config log report
ci2-upstream-kcsan-gce 2020/02/09 09:42 https://github.com/google/ktsan.git kcsan f60f0f543333 6ece2ea5 .config log report
ci2-upstream-kcsan-gce 2020/02/08 11:00 https://github.com/google/ktsan.git kcsan f60f0f543333 06150bf1 .config log report
ci2-upstream-kcsan-gce 2020/02/07 14:35 https://github.com/google/ktsan.git kcsan 6cccb8ba35bd 06150bf1 .config log report
ci2-upstream-kcsan-gce 2020/02/07 01:26 https://github.com/google/ktsan.git kcsan 245a43005292 06150bf1 .config log report
ci2-upstream-kcsan-gce 2020/02/06 14:49 https://github.com/google/ktsan.git kcsan 245a43005292 5be3a391 .config log report
ci2-upstream-kcsan-gce 2020/02/05 13:41 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config log report
ci2-upstream-kcsan-gce 2020/02/02 12:55 https://github.com/google/ktsan.git kcsan 245a43005292 93e5e335 .config log report
ci2-upstream-kcsan-gce 2020/02/01 22:36 https://github.com/google/ktsan.git kcsan 245a43005292 2274ad39 .config log report
ci2-upstream-kcsan-gce 2020/02/01 10:55 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config log report
ci2-upstream-kcsan-gce 2020/01/31 19:36 https://github.com/google/ktsan.git kcsan 245a43005292 0eb59c27 .config log report
ci2-upstream-kcsan-gce 2020/01/29 15:50 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config log report
ci2-upstream-kcsan-gce 2020/01/28 17:09 https://github.com/google/ktsan.git kcsan 245a43005292 c8e81ce4 .config log report
ci2-upstream-kcsan-gce 2020/01/27 15:10 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config log report
ci2-upstream-kcsan-gce 2020/01/26 15:50 https://github.com/google/ktsan.git kcsan 245a43005292 dd56146d .config log report
ci2-upstream-kcsan-gce 2020/01/25 22:38 https://github.com/google/ktsan.git kcsan 245a43005292 f4e7270e .config log report
ci2-upstream-kcsan-gce 2020/01/24 06:32 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config log report
ci2-upstream-kcsan-gce 2020/01/23 14:54 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config log report
ci2-upstream-kcsan-gce 2020/01/22 17:47 https://github.com/google/ktsan.git kcsan 245a43005292 3334d684 .config log report
ci2-upstream-kcsan-gce 2020/01/20 22:21 https://github.com/google/ktsan.git kcsan 245a43005292 8eda0b95 .config log report
ci2-upstream-kcsan-gce 2020/01/20 09:52 https://github.com/google/ktsan.git kcsan 245a43005292 c40da18c .config log report
ci2-upstream-kcsan-gce 2020/01/19 15:19 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config log report
ci2-upstream-kcsan-gce 2020/01/18 21:13 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config log report
ci2-upstream-kcsan-gce 2020/01/16 12:04 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config log report
ci2-upstream-kcsan-gce 2020/01/15 17:32 https://github.com/google/ktsan.git kcsan 245a43005292 f9b69507 .config log report
ci2-upstream-kcsan-gce 2020/01/15 16:12 https://github.com/google/ktsan.git kcsan 245a43005292 069a5a44 .config log report
ci2-upstream-kcsan-gce 2020/01/14 19:18 https://github.com/google/ktsan.git kcsan 245a43005292 fa12bd3c .config log report
ci2-upstream-kcsan-gce 2020/01/13 23:04 https://github.com/google/ktsan.git kcsan 245a43005292 32881205 .config log report
ci2-upstream-kcsan-gce 2020/01/13 12:03 https://github.com/google/ktsan.git kcsan 245a43005292 99565c1a .config log report
ci2-upstream-kcsan-gce 2020/01/12 22:39 https://github.com/google/ktsan.git kcsan 245a43005292 53faa9fe .config log report
ci2-upstream-kcsan-gce 2020/01/12 12:17 https://github.com/google/ktsan.git kcsan 245a43005292 31290a45 .config log report
ci2-upstream-kcsan-gce 2020/01/11 03:24 https://github.com/google/ktsan.git kcsan 245a43005292 4c04afaa .config log report
ci2-upstream-kcsan-gce 2020/01/10 14:49 https://github.com/google/ktsan.git kcsan 245a43005292 532ec44e .config log report
ci2-upstream-kcsan-gce 2020/01/09 14:49 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config log report
ci2-upstream-kcsan-gce 2020/01/08 10:15 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config log report
ci2-upstream-kcsan-gce 2020/01/07 22:12 https://github.com/google/ktsan.git kcsan 245a43005292 6738e0b3 .config log report
ci2-upstream-kcsan-gce 2020/01/07 09:17 https://github.com/google/ktsan.git kcsan 245a43005292 1bcd407e .config log report
ci2-upstream-kcsan-gce 2020/01/06 20:51 https://github.com/google/ktsan.git kcsan 245a43005292 53430d97 .config log report
ci2-upstream-kcsan-gce 2020/01/06 00:10 https://github.com/google/ktsan.git kcsan 245a43005292 438e1227 .config log report
ci2-upstream-kcsan-gce 2020/01/05 12:38 https://github.com/google/ktsan.git kcsan 245a43005292 d646e21f .config log report
ci2-upstream-kcsan-gce 2020/01/03 22:12 https://github.com/google/ktsan.git kcsan 245a43005292 68256974 .config log report
ci2-upstream-kcsan-gce 2020/01/03 09:45 https://github.com/google/ktsan.git kcsan 245a43005292 9dcc1191 .config log report
ci2-upstream-kcsan-gce 2019/12/31 16:56 https://github.com/google/ktsan.git kcsan 245a43005292 25a0186e .config log report
ci2-upstream-kcsan-gce 2019/12/31 05:27 https://github.com/google/ktsan.git kcsan 245a43005292 7f117e28 .config log report
ci2-upstream-kcsan-gce 2019/12/30 16:23 https://github.com/google/ktsan.git kcsan 245a43005292 6b36d338 .config log report
ci2-upstream-kcsan-gce 2019/12/28 10:56 https://github.com/google/ktsan.git kcsan 245a43005292 af6b8ef8 .config log report
ci2-upstream-kcsan-gce 2019/10/04 14:10 https://github.com/google/ktsan.git kcsan b4bd934316dc c86336cf .config log report
* Struck through repros no longer work on HEAD.