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KCSAN: data-race in process_srcu / synchronize_srcu

Status: fixed on 2020/02/18 14:31
Subsystems: block
[Documentation on labels]
Reported-by: syzbot+08f3e9d26e5541e1ecf2@syzkaller.appspotmail.com
Fix commit: 844a378de337 srcu: Apply *_ONCE() to ->srcu_last_gp_end
First crash: 1638d, last: 1532d
▶ ▼ Discussions (5)
Title Replies (including bot) Last reply
[PATCH 5.4 000/309] 5.4.19-stable review 321 (321) 2020/02/12 21:17
[PATCH 5.5 000/367] 5.5.3-stable review 385 (385) 2020/02/12 07:27
[tip: core/rcu] srcu: Apply *_ONCE() to ->srcu_last_gp_end 1 (1) 2020/01/25 10:42
[PATCH tip/core/rcu 0/12] Miscellaneous fixes for v5.6 21 (21) 2019/12/12 09:31
KCSAN: data-race in process_srcu / synchronize_srcu 6 (7) 2019/11/19 03:54

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

write to 0xffffffff8625b2e0 of 8 bytes by task 44 on cpu 1:
 srcu_gp_end kernel/rcu/srcutree.c:533 [inline]
 srcu_advance_state kernel/rcu/srcutree.c:1146 [inline]
 process_srcu+0x207/0x780 kernel/rcu/srcutree.c:1237
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffffff8625b2e0 of 8 bytes by task 15683 on cpu 0:
 srcu_might_be_idle kernel/rcu/srcutree.c:784 [inline]
 synchronize_srcu+0x107/0x214 kernel/rcu/srcutree.c:996
 fsnotify_mark_destroy_workfn+0xef/0x230 fs/notify/mark.c:832
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15683 Comm: kworker/u4:7 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound fsnotify_mark_destroy_workfn
==================================================================

Crashes (112):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/07 03:37 https://github.com/google/ktsan.git kcsan 245a43005292 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/02/06 12:28 https://github.com/google/ktsan.git kcsan 245a43005292 5be3a391 .config console log report ci2-upstream-kcsan-gce
2020/02/05 16:07 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2020/02/02 12:49 https://github.com/google/ktsan.git kcsan 245a43005292 93e5e335 .config console log report ci2-upstream-kcsan-gce
2020/02/01 23:26 https://github.com/google/ktsan.git kcsan 245a43005292 2274ad39 .config console log report ci2-upstream-kcsan-gce
2020/02/01 13:25 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config console log report ci2-upstream-kcsan-gce
2020/01/31 21:46 https://github.com/google/ktsan.git kcsan 245a43005292 0eb59c27 .config console log report ci2-upstream-kcsan-gce
2020/01/29 16:30 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config console log report ci2-upstream-kcsan-gce
2020/01/28 17:00 https://github.com/google/ktsan.git kcsan 245a43005292 c8e81ce4 .config console log report ci2-upstream-kcsan-gce
2020/01/27 15:57 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config console log report ci2-upstream-kcsan-gce
2020/01/26 18:27 https://github.com/google/ktsan.git kcsan 245a43005292 dd56146d .config console log report ci2-upstream-kcsan-gce
2020/01/26 00:03 https://github.com/google/ktsan.git kcsan 245a43005292 f4e7270e .config console log report ci2-upstream-kcsan-gce
2020/01/24 14:09 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/23 17:48 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config console log report ci2-upstream-kcsan-gce
2020/01/22 18:49 https://github.com/google/ktsan.git kcsan 245a43005292 3334d684 .config console log report ci2-upstream-kcsan-gce
2020/01/20 21:56 https://github.com/google/ktsan.git kcsan 245a43005292 8eda0b95 .config console log report ci2-upstream-kcsan-gce
2020/01/20 14:30 https://github.com/google/ktsan.git kcsan 245a43005292 c40da18c .config console log report ci2-upstream-kcsan-gce
2020/01/20 04:09 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2020/01/18 21:54 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2020/01/16 13:01 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/16 03:17 https://github.com/google/ktsan.git kcsan 245a43005292 f9b69507 .config console log report ci2-upstream-kcsan-gce
2020/01/15 15:51 https://github.com/google/ktsan.git kcsan 245a43005292 069a5a44 .config console log report ci2-upstream-kcsan-gce
2020/01/15 08:43 https://github.com/google/ktsan.git kcsan 245a43005292 fa12bd3c .config console log report ci2-upstream-kcsan-gce
2020/01/14 01:11 https://github.com/google/ktsan.git kcsan 245a43005292 32881205 .config console log report ci2-upstream-kcsan-gce
2020/01/13 11:33 https://github.com/google/ktsan.git kcsan 245a43005292 99565c1a .config console log report ci2-upstream-kcsan-gce
2020/01/13 02:09 https://github.com/google/ktsan.git kcsan 245a43005292 53faa9fe .config console log report ci2-upstream-kcsan-gce
2020/01/12 11:33 https://github.com/google/ktsan.git kcsan 245a43005292 31290a45 .config console log report ci2-upstream-kcsan-gce
2020/01/11 03:23 https://github.com/google/ktsan.git kcsan 245a43005292 4c04afaa .config console log report ci2-upstream-kcsan-gce
2020/01/10 15:50 https://github.com/google/ktsan.git kcsan 245a43005292 532ec44e .config console log report ci2-upstream-kcsan-gce
2020/01/09 15:05 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/08 14:20 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config console log report ci2-upstream-kcsan-gce
2020/01/08 02:36 https://github.com/google/ktsan.git kcsan 245a43005292 6738e0b3 .config console log report ci2-upstream-kcsan-gce
2020/01/07 11:21 https://github.com/google/ktsan.git kcsan 245a43005292 1bcd407e .config console log report ci2-upstream-kcsan-gce
2020/01/07 05:02 https://github.com/google/ktsan.git kcsan 245a43005292 53430d97 .config console log report ci2-upstream-kcsan-gce
2020/01/06 03:18 https://github.com/google/ktsan.git kcsan 245a43005292 438e1227 .config console log report ci2-upstream-kcsan-gce
2020/01/05 15:32 https://github.com/google/ktsan.git kcsan 245a43005292 d646e21f .config console log report ci2-upstream-kcsan-gce
2020/01/03 22:03 https://github.com/google/ktsan.git kcsan 245a43005292 68256974 .config console log report ci2-upstream-kcsan-gce
2020/01/03 11:33 https://github.com/google/ktsan.git kcsan 245a43005292 9dcc1191 .config console log report ci2-upstream-kcsan-gce
2020/01/01 04:27 https://github.com/google/ktsan.git kcsan 245a43005292 25a0186e .config console log report ci2-upstream-kcsan-gce
2019/12/31 07:00 https://github.com/google/ktsan.git kcsan 245a43005292 7f117e28 .config console log report ci2-upstream-kcsan-gce
2019/12/31 00:51 https://github.com/google/ktsan.git kcsan 245a43005292 6b36d338 .config console log report ci2-upstream-kcsan-gce
2019/12/28 13:26 https://github.com/google/ktsan.git kcsan 245a43005292 af6b8ef8 .config console log report ci2-upstream-kcsan-gce
2019/10/23 19:12 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.