KCSAN: data-race in exit_signals / kthread_unpark (2)

Status: closed as invalid on 2020/06/18 14:24
Subsystems: kernel
[Documentation on labels]
First crash: 2464d, last: 2265d
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in exit_signals / kthread_unpark kernel 6 3 2481d 2484d 0/29 closed as invalid on 2019/11/19 13:44
upstream KCSAN: data-race in exit_signals / kthread_unpark (3) kernel 6 48 1907d 2082d 0/29 auto-closed as invalid on 2021/07/05 17:15

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

write to 0xffff88810e7ac024 of 4 bytes by task 10910 on cpu 1:
 exit_signals+0x135/0x4c0 kernel/signal.c:2827
 do_exit+0x17b/0x11e0 kernel/exit.c:744
 kthread+0x1aa/0x230 kernel/kthread.c:270
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff88810e7ac024 of 4 bytes by task 9114 on cpu 0:
 to_kthread kernel/kthread.c:75 [inline]
 kthread_unpark+0x1f/0xd0 kernel/kthread.c:487
 kthread_stop+0xd5/0x370 kernel/kthread.c:570
 loop_unprepare_queue drivers/block/loop.c:917 [inline]
 __loop_clr_fd+0x39f/0x710 drivers/block/loop.c:1179
 lo_release+0x140/0x150 drivers/block/loop.c:1852
 __blkdev_put+0x29c/0x3e0 fs/block_dev.c:1909
 blkdev_put+0x84/0x2b0 fs/block_dev.c:1971
 kill_block_super+0x85/0xa0 fs/super.c:1447
 deactivate_locked_super+0x5d/0xb0 fs/super.c:335
 deactivate_super fs/super.c:366 [inline]
 deactivate_super+0xca/0xe0 fs/super.c:362
 cleanup_mnt+0x27a/0x330 fs/namespace.c:1102
 __cleanup_mnt+0x1c/0x30 fs/namespace.c:1109
 task_work_run+0xba/0x120 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2ae/0x2c0 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9114 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/07 21:13 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 7751efd0 .config console log report ci2-upstream-kcsan-gce
2020/06/05 02:42 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2420d1bc .config console log report ci2-upstream-kcsan-gce
2020/06/01 01:04 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a0331e89 .config console log report ci2-upstream-kcsan-gce
2020/05/15 21:56 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d7f9fffa .config console log report ci2-upstream-kcsan-gce
2020/05/13 00:21 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a44eb8f7 .config console log report ci2-upstream-kcsan-gce
2020/05/10 13:07 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 8742a2b9 .config console log report ci2-upstream-kcsan-gce
2020/05/06 11:22 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 35b8eb30 .config console log report ci2-upstream-kcsan-gce
2020/05/05 03:51 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9941337c .config console log report ci2-upstream-kcsan-gce
2020/03/31 09:04 https://github.com/google/ktsan.git kcsan 40959e34d670 c8d1cc20 .config console log report ci2-upstream-kcsan-gce
2020/03/07 20:24 https://github.com/google/ktsan.git kcsan 941e0d917bbf 2e9971bb .config console log report ci2-upstream-kcsan-gce
2020/02/13 09:38 https://github.com/google/ktsan.git kcsan f60f0f543333 84f4fc8a .config console log report ci2-upstream-kcsan-gce
2020/02/02 09:12 https://github.com/google/ktsan.git kcsan 245a43005292 2274ad39 .config console log report ci2-upstream-kcsan-gce
2020/01/19 13:19 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2019/12/13 17:58 https://github.com/google/ktsan.git kcsan 245a43005292 a5c1ab05 .config console log report ci2-upstream-kcsan-gce
2019/12/12 17:29 https://github.com/google/ktsan.git kcsan ef798c30ba4e 08003f64 .config console log report ci2-upstream-kcsan-gce
2019/12/10 16:24 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4b83c8fb .config console log report ci2-upstream-kcsan-gce
2019/11/30 03:06 https://github.com/google/ktsan.git kcsan ef798c30ba4e 3a75be00 .config console log report ci2-upstream-kcsan-gce
2019/11/28 12:54 https://github.com/google/ktsan.git kcsan ef798c30ba4e 97264cb1 .config console log report ci2-upstream-kcsan-gce
2019/11/22 07:33 https://github.com/google/ktsan.git kcsan 5863cc791e4c 8098ea0f .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.