syzbot


INFO: task hung in lo_release

Status: public: reported syz repro on 2019/04/14 00:02
Reported-by: syzbot+080cc4a0776f78b26616@syzkaller.appspotmail.com
First crash: 2241d, last: 1608d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in lo_release block 1 2107d 2107d 11/26 fixed on 2019/01/15 20:25
android-49 INFO: task hung in lo_release 867 1742d 1837d 0/3 auto-closed as invalid on 2019/10/25 14:11
linux-4.14 INFO: task hung in lo_release (2) C 19 424d 1497d 0/1 upstream: reported C repro on 2020/03/19 00:28
upstream INFO: task hung in lo_release (2) block 38 884d 884d 0/26 closed as dup on 2021/11/23 00:29
android-49 INFO: task hung in lo_release (2) 3 1620d 1632d 0/3 auto-closed as invalid on 2020/03/16 04:39
android-414 INFO: task hung in lo_release syz 1670 1614d 1839d 0/1 public: reported syz repro on 2019/04/12 00:01
linux-4.14 INFO: task hung in lo_release syz done 128 1727d 1840d 1/1 fixed on 2019/12/17 00:29

Sample crash report:
INFO: task blkid:2613 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D ffff8800b1dd7af8 29008  2613    589 0x00000004
 ffff8800b1dd7af8 ffff8800b25997c0 62c6ad62307c3c56 ffff8800b25997c0
 0000000000000002 ffff8800b259a000 ffff8801db71f180 ffff8801db71f1a8
 ffff8801db71e898 ffff8800b259af80 ffff8800b25997c0 ffffed00163ba001
Call Trace:
 [<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
 [<ffffffff8270a333>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388
 [<ffffffff8270c492>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8270c492>] mutex_lock_nested+0x3c2/0xb80 kernel/locking/mutex.c:621
 [<ffffffff81d48124>] __lo_release drivers/block/loop.c:1653 [inline]
 [<ffffffff81d48124>] lo_release+0x84/0x1b0 drivers/block/loop.c:1676
 [<ffffffff8154e4e1>] __blkdev_put+0x461/0x840 fs/block_dev.c:1535
 [<ffffffff8154f738>] blkdev_put+0x88/0x560 fs/block_dev.c:1600
 [<ffffffff8154fc9b>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1607
 [<ffffffff8149c8c6>] __fput+0x246/0x710 fs/file_table.c:208
 [<ffffffff8149ce16>] ____fput+0x16/0x20 fs/file_table.c:244
 [<ffffffff8112f352>] task_work_run+0x202/0x2b0 kernel/task_work.c:115
 [<ffffffff81003dca>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff81003dca>] exit_to_usermode_loop+0x14a/0x170 arch/x86/entry/common.c:188
 [<ffffffff8100569b>] prepare_exit_to_usermode arch/x86/entry/common.c:221 [inline]
 [<ffffffff8100569b>] syscall_return_slowpath+0x25b/0x2e0 arch/x86/entry/common.c:286
 [<ffffffff82718ce1>] int_ret_from_sys_call+0x25/0xa3
3 locks held by blkid/2613:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8154e13b>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1516
 #1:  (loop_index_mutex){+.+.+.}, at: [<ffffffff81d480be>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1675
 #2:  (loop_ctl_mutex#2){+.+.+.}, at: [<ffffffff81d48124>] __lo_release drivers/block/loop.c:1653 [inline]
 #2:  (loop_ctl_mutex#2){+.+.+.}, at: [<ffffffff81d48124>] lo_release+0x84/0x1b0 drivers/block/loop.c:1676
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #4
task: ffff8801da6f4740 task.stack: ffff8800001d0000
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800001d7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001d7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2793805000 CR3: 00000000b4a58000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001d7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001d7d30 ffffffff81ab8252
Call Trace:
 [<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae lib/nmi_backtrace.c:85
 [<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813b4762>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1 
NMI backtrace for cpu 1
CPU: 1 PID: 1927 Comm: rsyslogd Not tainted 4.4.174+ #4
task: ffff8801d6d55f00 task.stack: ffff8801d6428000
RIP: 0033:[<00007f1cec2c1004>]  [<00007f1cec2c1004>] 0x7f1cec2c1004
RSP: 002b:00007f1ce9f68cf0  EFLAGS: 00000206
RAX: 0000000002469480 RBX: 0000000002469588 RCX: 0000000002469470
RDX: 000000000241de10 RSI: 0000000000000000 RDI: 00007f1ce9f68d00
RBP: 0000000002469580 R08: 00007f1cec5ab0a8 R09: 00007f1cec35d100
R10: 0fffffffffffffff R11: 0000000000000000 R12: 0000000000000000
R13: 00007f1ceb79e5a3 R14: 0000000000000574 R15: 00007f1ceb79d5e4
FS:  00007f1ce9f69700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f355c43da30 CR3: 00000001d875f000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Crashes (59):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/03/10 06:50 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 12365b99 .config console log report syz ci-android-44-kasan-gce
2019/03/07 19:23 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 8c085c5e .config console log report syz ci-android-44-kasan-gce
2019/02/22 04:14 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 7ff74a98 .config console log report syz ci-android-44-kasan-gce
2019/02/13 11:48 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 1eedba36 .config console log report syz ci-android-44-kasan-gce
2019/11/03 03:03 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b a41ca8fa .config console log report syz ci-android-44-kasan-gce-386
2019/03/10 06:47 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 12365b99 .config console log report syz ci-android-44-kasan-gce-386
2019/03/07 19:26 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 8c085c5e .config console log report syz ci-android-44-kasan-gce-386
2019/02/22 04:16 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 7ff74a98 .config console log report syz ci-android-44-kasan-gce-386
2019/02/13 11:36 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 1eedba36 .config console log report syz ci-android-44-kasan-gce-386
2019/02/13 07:50 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 1eedba36 .config console log report syz ci-android-44-kasan-gce-386
2019/02/13 05:45 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 1eedba36 .config console log report syz ci-android-44-kasan-gce-386
2019/11/15 18:39 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b cdac920b .config console log report ci-android-44-kasan-gce
2019/11/14 21:56 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b a24fe792 .config console log report ci-android-44-kasan-gce
2019/10/18 09:07 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 8c88c9c1 .config console log report ci-android-44-kasan-gce
2019/09/27 13:35 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b d8074e0b .config console log report ci-android-44-kasan-gce
2019/09/13 19:51 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 32d59357 .config console log report ci-android-44-kasan-gce
2019/08/29 17:32 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b fd37b39e .config console log report ci-android-44-kasan-gce
2019/07/28 23:18 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b c85e1c5b .config console log report ci-android-44-kasan-gce
2019/06/25 00:56 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 82c13b6b .config console log report ci-android-44-kasan-gce
2019/06/12 05:58 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b ea2f4006 .config console log report ci-android-44-kasan-gce
2019/06/04 12:59 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b e41a20c5 .config console log report ci-android-44-kasan-gce
2019/06/04 03:48 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b ce07a7ae .config console log report ci-android-44-kasan-gce
2019/04/28 07:51 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b b617407b .config console log report ci-android-44-kasan-gce
2019/04/26 06:49 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b b617407b .config console log report ci-android-44-kasan-gce
2019/04/02 14:13 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b dfd3394d .config console log report ci-android-44-kasan-gce
2019/03/27 19:45 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 4e668495 .config console log report ci-android-44-kasan-gce
2019/03/08 16:56 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 12365b99 .config console log report ci-android-44-kasan-gce
2019/03/04 22:01 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 7c693b52 .config console log report ci-android-44-kasan-gce
2019/02/13 02:59 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 1eedba36 .config console log report ci-android-44-kasan-gce
2019/02/06 08:48 https://android.googlesource.com/kernel/common android-4.4 6d1e42fb1a28 d672172c .config console log report ci-android-44-kasan-gce
2019/02/03 20:21 https://android.googlesource.com/kernel/common android-4.4 b3e9e81ee068 c198d5dd .config console log report ci-android-44-kasan-gce
2019/02/03 07:26 https://android.googlesource.com/kernel/common android-4.4 b3e9e81ee068 c198d5dd .config console log report ci-android-44-kasan-gce
2018/03/05 20:23 https://android.googlesource.com/kernel/common android-4.4 855ea747806b bbd5104f .config console log report ci-android-44-kasan-gce
2019/11/29 14:40 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b d29b9e84 .config console log report ci-android-44-kasan-gce-386
2019/11/20 22:54 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 8098ea0f .config console log report ci-android-44-kasan-gce-386
2019/11/02 23:45 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b a41ca8fa .config console log report ci-android-44-kasan-gce-386
2019/10/31 18:37 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b a41ca8fa .config console log report ci-android-44-kasan-gce-386
2019/10/12 00:16 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 426631dd .config console log report ci-android-44-kasan-gce-386
2019/09/26 02:51 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b a3355dba .config console log report ci-android-44-kasan-gce-386
2019/09/24 21:12 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 0942eab8 .config console log report ci-android-44-kasan-gce-386
2019/09/24 07:12 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b c68252d2 .config console log report ci-android-44-kasan-gce-386
2019/09/19 02:47 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 46c0be24 .config console log report ci-android-44-kasan-gce-386
2019/09/09 01:01 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b a60cb4cd .config console log report ci-android-44-kasan-gce-386
2019/08/30 19:51 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b fd37b39e .config console log report ci-android-44-kasan-gce-386
2019/07/17 16:41 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b f613a7c4 .config console log report ci-android-44-kasan-gce-386
2019/06/05 05:27 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b bfb4a51e .config console log report ci-android-44-kasan-gce-386
2019/05/25 18:22 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 85c57315 .config console log report ci-android-44-kasan-gce-386
2019/05/11 15:49 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 46caad94 .config console log report ci-android-44-kasan-gce-386
2019/05/10 16:35 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b cfeec859 .config console log report ci-android-44-kasan-gce-386
2019/04/06 12:32 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b c34fde03 .config console log report ci-android-44-kasan-gce-386
2019/02/24 16:50 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 7a06e792 .config console log report ci-android-44-kasan-gce-386
2019/02/23 09:51 https://android.googlesource.com/kernel/common android-4.4 62872f952d6b 18107ce0 .config console log report ci-android-44-kasan-gce-386
2019/02/05 02:02 https://android.googlesource.com/kernel/common android-4.4 f38b204f76a9 d672172c .config console log report ci-android-44-kasan-gce-386
2019/01/29 07:57 https://android.googlesource.com/kernel/common android-4.4 b3e9e81ee068 aa432daf .config console log report ci-android-44-kasan-gce-386
2019/01/29 05:33 https://android.googlesource.com/kernel/common android-4.4 b3e9e81ee068 aa432daf .config console log report ci-android-44-kasan-gce-386
2018/08/11 01:08 https://android.googlesource.com/kernel/common android-4.4 a5fc66599b61 7a88b141 .config console log report ci-android-44-kasan-gce-386
2018/04/02 04:14 https://android.googlesource.com/kernel/common android-4.4 38f41ec1cb31 dc889257 .config console log report ci-android-44-kasan-gce-386
2018/03/18 17:11 https://android.googlesource.com/kernel/common android-4.4 d63fdf61a4dc 08dacaa0 .config console log report ci-android-44-kasan-gce-386
2018/03/14 19:41 https://android.googlesource.com/kernel/common android-4.4 d63fdf61a4dc 08dacaa0 .config console log report ci-android-44-kasan-gce-386
* Struck through repros no longer work on HEAD.