syzbot


KCSAN: data-race in rcu_gp_fqs_check_wake / rcu_preempt_deferred_qs_irqrestore

Status: fixed on 2020/02/18 14:31
Subsystems: batman
[Documentation on labels]
Fix commit: 6935c3983b24 rcu: Avoid data-race in rcu_gp_fqs_check_wake()
First crash: 1659d, last: 1538d

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

write to 0xffffffff85c7d0d0 of 8 bytes by task 24003 on cpu 1:
 rcu_preempt_deferred_qs_irqrestore+0x43d/0x580 kernel/rcu/tree_plugin.h:496
 rcu_read_unlock_special kernel/rcu/tree_plugin.h:644 [inline]
 __rcu_read_unlock+0x16a/0x3d0 kernel/rcu/tree_plugin.h:383
 rcu_read_unlock include/linux/rcupdate.h:670 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline]
 batadv_nc_worker+0x13a/0x390 net/batman-adv/network-coding.c:718
 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 0xffffffff85c7d0d0 of 8 bytes by task 10 on cpu 0:
 rcu_gp_fqs_check_wake kernel/rcu/tree.c:1606 [inline]
 rcu_gp_fqs_check_wake+0x93/0xd0 kernel/rcu/tree.c:1596
 rcu_gp_fqs_loop+0x39d/0x580 kernel/rcu/tree.c:1661
 rcu_gp_kthread+0x143/0x230 kernel/rcu/tree.c:1821
 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: 10 Comm: rcu_preempt Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (99):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/07 00:25 https://github.com/google/ktsan.git kcsan 245a43005292 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/02/05 13:53 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2020/02/02 12:52 https://github.com/google/ktsan.git kcsan 245a43005292 93e5e335 .config console log report ci2-upstream-kcsan-gce
2020/02/01 10:49 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config console log report ci2-upstream-kcsan-gce
2020/01/31 18:53 https://github.com/google/ktsan.git kcsan 245a43005292 0eb59c27 .config console log report ci2-upstream-kcsan-gce
2020/01/29 15:28 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config console log report ci2-upstream-kcsan-gce
2020/01/28 17:56 https://github.com/google/ktsan.git kcsan 245a43005292 c8e81ce4 .config console log report ci2-upstream-kcsan-gce
2020/01/27 15:24 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config console log report ci2-upstream-kcsan-gce
2020/01/26 16:02 https://github.com/google/ktsan.git kcsan 245a43005292 dd56146d .config console log report ci2-upstream-kcsan-gce
2020/01/25 22:12 https://github.com/google/ktsan.git kcsan 245a43005292 f4e7270e .config console log report ci2-upstream-kcsan-gce
2020/01/24 06:36 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/23 14:41 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config console log report ci2-upstream-kcsan-gce
2020/01/22 18:40 https://github.com/google/ktsan.git kcsan 245a43005292 3334d684 .config console log report ci2-upstream-kcsan-gce
2020/01/20 21:50 https://github.com/google/ktsan.git kcsan 245a43005292 8eda0b95 .config console log report ci2-upstream-kcsan-gce
2020/01/20 10:06 https://github.com/google/ktsan.git kcsan 245a43005292 c40da18c .config console log report ci2-upstream-kcsan-gce
2020/01/19 15:29 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2020/01/18 21:18 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2020/01/16 11:59 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/13 11:06 https://github.com/google/ktsan.git kcsan 245a43005292 99565c1a .config console log report ci2-upstream-kcsan-gce
2020/01/12 22:53 https://github.com/google/ktsan.git kcsan 245a43005292 53faa9fe .config console log report ci2-upstream-kcsan-gce
2020/01/10 15:10 https://github.com/google/ktsan.git kcsan 245a43005292 532ec44e .config console log report ci2-upstream-kcsan-gce
2020/01/09 15:23 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/08 09:31 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config console log report ci2-upstream-kcsan-gce
2020/01/07 22:46 https://github.com/google/ktsan.git kcsan 245a43005292 6738e0b3 .config console log report ci2-upstream-kcsan-gce
2020/01/07 09:29 https://github.com/google/ktsan.git kcsan 245a43005292 1bcd407e .config console log report ci2-upstream-kcsan-gce
2020/01/06 20:19 https://github.com/google/ktsan.git kcsan 245a43005292 53430d97 .config console log report ci2-upstream-kcsan-gce
2020/01/06 00:18 https://github.com/google/ktsan.git kcsan 245a43005292 438e1227 .config console log report ci2-upstream-kcsan-gce
2020/01/05 12:16 https://github.com/google/ktsan.git kcsan 245a43005292 d646e21f .config console log report ci2-upstream-kcsan-gce
2020/01/03 21:58 https://github.com/google/ktsan.git kcsan 245a43005292 68256974 .config console log report ci2-upstream-kcsan-gce
2020/01/03 11:11 https://github.com/google/ktsan.git kcsan 245a43005292 9dcc1191 .config console log report ci2-upstream-kcsan-gce
2019/12/31 16:43 https://github.com/google/ktsan.git kcsan 245a43005292 25a0186e .config console log report ci2-upstream-kcsan-gce
2019/12/31 04:42 https://github.com/google/ktsan.git kcsan 245a43005292 7f117e28 .config console log report ci2-upstream-kcsan-gce
2019/12/30 16:08 https://github.com/google/ktsan.git kcsan 245a43005292 6b36d338 .config console log report ci2-upstream-kcsan-gce
2019/12/21 02:01 https://github.com/google/ktsan.git kcsan 245a43005292 bc586918 .config console log report ci2-upstream-kcsan-gce
2019/12/20 13:36 https://github.com/google/ktsan.git kcsan 245a43005292 34011c05 .config console log report ci2-upstream-kcsan-gce
2019/12/19 13:42 https://github.com/google/ktsan.git kcsan 245a43005292 36650b4b .config console log report ci2-upstream-kcsan-gce
2019/12/18 17:51 https://github.com/google/ktsan.git kcsan 245a43005292 79b211f7 .config console log report ci2-upstream-kcsan-gce
2019/12/18 04:49 https://github.com/google/ktsan.git kcsan 245a43005292 64ca0a37 .config console log report ci2-upstream-kcsan-gce
2019/12/18 04:45 https://github.com/google/ktsan.git kcsan 245a43005292 64ca0a37 .config console log report ci2-upstream-kcsan-gce
2019/12/16 09:35 https://github.com/google/ktsan.git kcsan 245a43005292 0ae38e44 .config console log report ci2-upstream-kcsan-gce
2019/12/14 06:14 https://github.com/google/ktsan.git kcsan 245a43005292 eef6e580 .config console log report ci2-upstream-kcsan-gce
2019/12/13 00:44 https://github.com/google/ktsan.git kcsan 245a43005292 08003f64 .config console log report ci2-upstream-kcsan-gce
2019/12/12 17:54 https://github.com/google/ktsan.git kcsan ef798c30ba4e 08003f64 .config console log report ci2-upstream-kcsan-gce
2019/12/10 20:59 https://github.com/google/ktsan.git kcsan ef798c30ba4e 101194eb .config console log report ci2-upstream-kcsan-gce
2019/12/10 04:10 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4b83c8fb .config console log report ci2-upstream-kcsan-gce
2019/12/07 19:16 https://github.com/google/ktsan.git kcsan ef798c30ba4e 1508f453 .config console log report ci2-upstream-kcsan-gce
2019/12/05 11:29 https://github.com/google/ktsan.git kcsan ef798c30ba4e 9fd5a512 .config console log report ci2-upstream-kcsan-gce
2019/12/04 13:54 https://github.com/google/ktsan.git kcsan ef798c30ba4e b2088328 .config console log report ci2-upstream-kcsan-gce
2019/12/02 18:28 https://github.com/google/ktsan.git kcsan ef798c30ba4e ab342da3 .config console log report ci2-upstream-kcsan-gce
2019/10/23 14:37 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
2019/10/23 02:24 https://github.com/google/ktsan.git kcsan 05f2236801fe d0686497 .config console log report ci2-upstream-kcsan-gce
2019/10/21 12:36 https://github.com/google/ktsan.git kcsan 05f2236801fe b24d2b8a .config console log report ci2-upstream-kcsan-gce
2019/10/14 21:38 https://github.com/google/ktsan.git kcsan d724f94f63de 05ad7292 .config console log report ci2-upstream-kcsan-gce
2019/10/14 13:03 https://github.com/google/ktsan.git kcsan d724f94f63de a6aef847 .config console log report ci2-upstream-kcsan-gce
2019/10/14 10:45 https://github.com/google/ktsan.git kcsan d724f94f63de a6aef847 .config console log report ci2-upstream-kcsan-gce
2019/10/13 08:38 https://github.com/google/ktsan.git kcsan d724f94f63de 2f661ec4 .config console log report ci2-upstream-kcsan-gce
2019/10/08 19:21 https://github.com/google/ktsan.git kcsan d724f94f63de b1ebbfef .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.