KCSAN: data-race in io_sq_thread / percpu_ref_kill_and_confirm

Status: auto-closed as invalid on 2021/01/21 04:19
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+a5a066a41083b8c5e929@syzkaller.appspotmail.com
First crash: 2309d, last: 2064d

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

write to 0xffff88810b411800 of 8 bytes by task 12822 on cpu 1:
 percpu_ref_kill_and_confirm+0x75/0x190 lib/percpu-refcount.c:386
 percpu_ref_kill include/linux/percpu-refcount.h:149 [inline]
 __io_uring_register fs/io_uring.c:9614 [inline]
 __do_sys_io_uring_register+0x137/0x1c50 fs/io_uring.c:9755
 __se_sys_io_uring_register fs/io_uring.c:9737 [inline]
 __x64_sys_io_uring_register+0x4f/0x60 fs/io_uring.c:9737
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810b411800 of 8 bytes by task 12813 on cpu 0:
 percpu_ref_is_dying include/linux/percpu-refcount.h:352 [inline]
 __io_sq_thread fs/io_uring.c:6701 [inline]
 io_sq_thread+0x50f/0xcd0 fs/io_uring.c:6794
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12813 Comm: io_uring-sq Not tainted 5.10.0-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: 12813 Comm: io_uring-sq Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x116/0x15d lib/dump_stack.c:120
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x47b/0x4e0 kernel/kcsan/core.c:568
 percpu_ref_is_dying include/linux/percpu-refcount.h:352 [inline]
 __io_sq_thread fs/io_uring.c:6701 [inline]
 io_sq_thread+0x50f/0xcd0 fs/io_uring.c:6794
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (407):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/12/17 04:18 upstream 5e60366d56c6 04201c06 .config console log report info ci2-upstream-kcsan-gce
2020/12/16 17:55 upstream d01e7f10dae2 649595c6 .config console log report info ci2-upstream-kcsan-gce
2020/12/15 20:55 upstream 148842c98a24 f213e07e .config console log report info ci2-upstream-kcsan-gce
2020/12/15 17:57 upstream 148842c98a24 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 23:02 upstream fab0fca1da5c 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 11:06 upstream 2c85ebc57b3e b22a7ec3 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 03:36 upstream ec6f5e0e5ca0 8f160dd5 .config console log report info ci2-upstream-kcsan-gce
2020/12/13 11:41 upstream 6bff9bb8a292 bca53db9 .config console log report info ci2-upstream-kcsan-gce
2020/12/13 01:42 upstream 7b1b868e1d91 bca53db9 .config console log report info ci2-upstream-kcsan-gce
2020/12/12 06:08 upstream 7f376f1917d7 bca53db9 .config console log report info ci2-upstream-kcsan-gce
2020/12/11 20:25 upstream 33dc9614dc20 ba24ffcd .config console log report info ci2-upstream-kcsan-gce
2020/12/11 07:54 upstream 9fca90cf2892 f900b48c .config console log report info ci2-upstream-kcsan-gce
2020/12/10 18:34 upstream a2f5ea9e314b 2a55c22b .config console log report info ci2-upstream-kcsan-gce
2020/12/10 00:21 upstream ca4bbdaf1716 c090b4da .config console log report info ci2-upstream-kcsan-gce
2020/12/09 09:51 upstream a68a0262abda 99917735 .config console log report info ci2-upstream-kcsan-gce
2020/12/09 02:39 upstream 7d8761ba27fc 40cc414d .config console log report info ci2-upstream-kcsan-gce
2020/12/08 17:55 upstream cd796ed33450 9af51e31 .config console log report info ci2-upstream-kcsan-gce
2020/12/07 23:29 upstream cd796ed33450 51a9082e .config console log report info ci2-upstream-kcsan-gce
2020/12/07 15:04 upstream 0477e9288185 f80ce148 .config console log report info ci2-upstream-kcsan-gce
2020/12/07 02:04 upstream 8100a58044f8 c521566d .config console log report info ci2-upstream-kcsan-gce
2020/12/06 13:57 upstream 7059c2c00a21 f12ba0c5 .config console log report info ci2-upstream-kcsan-gce
2020/12/06 03:09 upstream 32f741b02f1a 50503117 .config console log report info ci2-upstream-kcsan-gce
2020/12/05 08:36 upstream b3298500b23f 0ef84591 .config console log report info ci2-upstream-kcsan-gce
2020/12/04 19:10 upstream e87297fa080a 20366b87 .config console log report info ci2-upstream-kcsan-gce
2020/12/03 18:52 upstream 34816d20f173 59ad4022 .config console log report info ci2-upstream-kcsan-gce
2020/12/03 05:21 upstream 3bb61aa61828 8c9190ef .config console log report info ci2-upstream-kcsan-gce
2020/12/02 18:01 upstream 509a15421674 eff43e99 .config console log report info ci2-upstream-kcsan-gce
2020/12/02 01:55 upstream 509a15421674 c42a35e9 .config console log report info ci2-upstream-kcsan-gce
2020/12/01 11:40 upstream b65054597872 07bfe8a5 .config console log report info ci2-upstream-kcsan-gce
2020/12/01 10:17 upstream b65054597872 b3a34598 .config console log report info ci2-upstream-kcsan-gce
2020/11/30 21:49 upstream b65054597872 76831598 .config console log report info ci2-upstream-kcsan-gce
2020/11/30 06:36 upstream b65054597872 a0092f9d .config console log report info ci2-upstream-kcsan-gce
2020/11/29 21:37 upstream aae5ab854e38 a0092f9d .config console log report info ci2-upstream-kcsan-gce
2020/11/29 03:50 upstream 67f34fa8893e a0092f9d .config console log report info ci2-upstream-kcsan-gce
2020/11/28 22:57 upstream 67f34fa8893e 3c7136c0 .config console log report info ci2-upstream-kcsan-gce
2020/11/28 17:28 upstream c84e1efae022 3c7136c0 .config console log report info ci2-upstream-kcsan-gce
2020/11/28 04:19 upstream c84e1efae022 486f93ef .config console log report info ci2-upstream-kcsan-gce
2020/11/28 00:54 upstream 85a2c56cb445 486f93ef .config console log report info ci2-upstream-kcsan-gce
2020/11/27 03:41 upstream 4df910620beb 5018c946 .config console log report info ci2-upstream-kcsan-gce
2020/11/26 11:28 upstream fa02fcd94b0c 2f1cec62 .config console log report info ci2-upstream-kcsan-gce
2020/11/26 05:51 upstream fa02fcd94b0c 2f1cec62 .config console log report info ci2-upstream-kcsan-gce
2020/11/26 00:44 upstream fa02fcd94b0c 3f581b43 .config console log report info ci2-upstream-kcsan-gce
2020/11/25 16:43 upstream 127c501a03d5 3f581b43 .config console log report info ci2-upstream-kcsan-gce
2020/11/24 23:08 upstream 80145ac2f739 e34b696c .config console log report info ci2-upstream-kcsan-gce
2020/11/24 09:44 upstream d5beb3140f91 1ab681a4 .config console log report info ci2-upstream-kcsan-gce
2020/11/23 15:04 upstream 418baf2c28f3 878fb17a .config console log report info ci2-upstream-kcsan-gce
2020/11/22 06:02 upstream a349e4c65960 0d27f508 .config console log report info ci2-upstream-kcsan-gce
2020/06/13 05:34 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f4724dd3 .config console log report ci2-upstream-kcsan-gce
2020/06/09 11:47 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0d60b78a .config console log report ci2-upstream-kcsan-gce
2020/04/15 18:40 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3f3c5574 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.