syzbot


INFO: task hung in __blkdev_get

Status: fixed on 2018/05/08 18:30
Reported-by: syzbot+48594378e9851eab70bcd6f99327c7db58c5a28a@syzkaller.appspotmail.com
Fix commit: 1e047eaab3bb block/loop: fix deadlock after loop_set_status
First crash: 1823d, last: 1689d
similar bugs (9):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in __blkdev_get C 1504 1094d 1326d 0/3 public: reported C repro on 2019/04/12 00:00
android-44 INFO: task hung in __blkdev_get syz 521 1096d 1324d 0/2 public: reported syz repro on 2019/04/14 00:02
android-414 INFO: task hung in __blkdev_get 1859 1094d 1325d 0/1 auto-closed as invalid on 2020/02/28 16:13
upstream INFO: task hung in __blkdev_get (3) 1 1319d 1319d 0/24 closed as invalid on 2019/05/08 13:05
upstream INFO: task hung in __blkdev_get (2) 11 1418d 1542d 0/24 closed as dup on 2018/09/08 15:48
linux-4.14 INFO: task hung in __blkdev_get C 736 15d 1327d 0/1 upstream: reported C repro on 2019/04/11 13:17
linux-4.19 INFO: task hung in __blkdev_get C error 129 4d23h 1203d 0/1 upstream: reported C repro on 2019/08/13 00:10
upstream INFO: task hung in __blkdev_get (4) 1 1138d 1138d 0/24 auto-closed as invalid on 2020/01/15 05:33
upstream INFO: task hung in __blkdev_get (5) 8 717d 931d 0/24 auto-closed as invalid on 2021/03/11 14:46

Sample crash report:
INFO: task blkid:3090 blocked for more than 120 seconds.
      Not tainted 4.15.0-rc1-mm1+ #29
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blkid           D23696  3090   3062 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2800 [inline]
 __schedule+0x8eb/0x2060 kernel/sched/core.c:3376
 schedule+0xf5/0x430 kernel/sched/core.c:3435
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3493
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439
 blkdev_get+0x3a1/0xad0 fs/block_dev.c:1591
 blkdev_open+0x1e4/0x270 fs/block_dev.c:1749
 do_dentry_open+0x682/0xd70 fs/open.c:752
 vfs_open+0x107/0x230 fs/open.c:866
 do_last fs/namei.c:3379 [inline]
 path_openat+0x1157/0x3530 fs/namei.c:3519
 do_filp_open+0x25b/0x3b0 fs/namei.c:3554
 do_sys_open+0x502/0x6d0 fs/open.c:1059
 SYSC_open fs/open.c:1077 [inline]
 SyS_open+0x2d/0x40 fs/open.c:1072
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x7fe5c5bfc120
RSP: 002b:00007ffde0d34f08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5c5bfc120
RDX: 00007ffde0d35f34 RSI: 0000000000000000 RDI: 00007ffde0d35f34
RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000211e030
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005

Showing all locks held in the system:
2 locks held by khungtaskd/675:
 #0:  (rcu_read_lock){....}, at: [<000000007fb79bbe>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0:  (rcu_read_lock){....}, at: [<000000007fb79bbe>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
 #1:  (tasklist_lock){.+.+}, at: [<0000000035358c26>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554
1 lock held by rsyslogd/2973:
 #0:  (&f->f_pos_lock){+.+.}, at: [<0000000001261d81>] __fdget_pos+0x131/0x1a0 fs/file.c:770
2 locks held by getty/3055:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3056:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3057:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3058:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3059:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3060:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
2 locks held by getty/3061:
 #0:  (&tty->ldisc_sem){++++}, at: [<000000005cc11435>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000008d2b0f7>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131
1 lock held by syzkaller346228/3087:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<0000000099fa8891>] __blkdev_put+0xa7/0x7c0 fs/block_dev.c:1757
1 lock held by blkid/3090:
 #0:  (&bdev->bd_mutex){+.+.}, at: [<00000000d4caea9e>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 675 Comm: khungtaskd Not tainted 4.15.0-rc1-mm1+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0x90c/0xd60 kernel/hung_task.c:249
 kthread+0x37a/0x440 kernel/kthread.c:238
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:517
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.15.0-rc1-mm1+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: 0000000064c7084b task.stack: 00000000bb7e08d1
RIP: 0010:sched_ttwu_pending+0x0/0x270 kernel/sched/core.c:1584
RSP: 0018:ffff8801db507d68 EFLAGS: 00000046
RAX: 0000000000000003 RBX: 0000000000027900 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801da3894a0
RBP: ffff8801db507e90 R08: 0000000000000001 R09: ffff88021fff8048
R10: ffff88021fff8050 R11: ffff88021fff805d R12: ffff8801da388300
R13: 1ffff1003b6a0fb1 R14: ffff8801db507e68 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe5c5bfc110 CR3: 00000001d1b96000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277
 reschedule_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:931
 </IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffff8801da397da8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffff1003b472fb8 RCX: 0000000000000000
RDX: 1ffffffff0bd9744 RSI: 0000000000000001 RDI: ffffffff85ecba20
RBP: ffff8801da397da8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8801da397e60 R14: ffffffff865eca20 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline]
 default_idle+0xbf/0x430 arch/x86/kernel/process.c:355
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:346
 default_idle_call+0x36/0x90 kernel/sched/idle.c:98
 cpuidle_idle_call kernel/sched/idle.c:156 [inline]
 do_idle+0x24a/0x3b0 kernel/sched/idle.c:246
 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:351
 start_secondary+0x2dd/0x3e0 arch/x86/kernel/smpboot.c:277
 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237
Code: ff ff 4c 89 85 70 ff ff ff e8 ad 12 5a 00 48 8b 95 68 ff ff ff 4c 8b 85 70 ff ff ff e9 19 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 4c 8d ad 78 ff ff ff 49 be 00 00 

Crashes (662):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-mmots-kasan-gce 2017/12/03 15:49 mmots 4131d5166185 29b0fd90 .config log report syz C
ci-upstream-kasan-gce-386 2018/03/10 06:33 upstream 719ea86151f3 36d1c454 .config log report syz
ci-upstream-kasan-gce 2018/04/14 08:16 upstream 1bad9ce155a7 7a67784c .config log report
ci-upstream-kasan-gce 2018/04/14 05:18 upstream 1bad9ce155a7 7a67784c .config log report
ci-upstream-kasan-gce-root 2018/04/14 00:56 upstream 1bad9ce155a7 7a67784c .config log report
ci-upstream-kasan-gce 2018/04/13 23:07 upstream 1bad9ce155a7 7a67784c .config log report
ci-upstream-kasan-gce 2018/04/13 15:02 upstream 16e205cf42da 0a0c5db6 .config log report
ci-upstream-kasan-gce 2018/04/13 04:08 upstream c17b0aadb7d8 eb2295de .config log report
ci-upstream-kasan-gce 2018/04/13 01:09 upstream c17b0aadb7d8 eb2295de .config log report
ci-upstream-kasan-gce-root 2018/04/12 12:32 upstream b284d4d5a678 9cd56d71 .config log report
ci-upstream-kasan-gce 2018/04/12 09:53 upstream b284d4d5a678 9cd56d71 .config log report
ci-upstream-kasan-gce-root 2018/04/11 22:34 upstream b284d4d5a678 9cd56d71 .config log report
ci-upstream-kasan-gce 2018/04/11 13:45 upstream b284d4d5a678 8b8de427 .config log report
ci-upstream-kasan-gce 2018/04/11 01:18 upstream c18bb396d3d2 8b8de427 .config log report
ci-upstream-kasan-gce 2018/04/10 23:19 upstream c18bb396d3d2 8b8de427 .config log report
ci-upstream-kasan-gce-root 2018/04/10 20:15 upstream c18bb396d3d2 8b8de427 .config log report
ci-upstream-kasan-gce 2018/04/10 14:03 upstream c18bb396d3d2 8e873e9d .config log report
ci-upstream-kasan-gce 2018/04/10 04:53 upstream fd40ffc72e2f b9f65507 .config log report
ci-upstream-kasan-gce 2018/04/09 13:46 upstream 3fd14cdcc05a f13fb445 .config log report
ci-upstream-kasan-gce-root 2018/04/08 18:35 upstream 3fd14cdcc05a 77bd5117 .config log report
ci-upstream-kasan-gce 2018/04/07 21:54 upstream 3fd14cdcc05a 66f22a7f .config log report
ci-upstream-kasan-gce 2018/04/07 10:39 upstream 3fd14cdcc05a d613535f .config log report
ci-upstream-kasan-gce 2018/04/06 09:34 upstream e02d37bf55a9 a932eae6 .config log report
ci-upstream-kasan-gce 2018/04/06 03:09 upstream e02d37bf55a9 a932eae6 .config log report
ci-upstream-kasan-gce-root 2018/04/05 13:30 upstream 06dd3dfeea60 5e1ccffc .config log report
ci-upstream-kasan-gce-root 2018/04/05 06:00 upstream 3e968c9f1401 676bd07e .config log report
ci-upstream-kasan-gce 2018/04/05 04:47 upstream 3e968c9f1401 676bd07e .config log report
ci-upstream-kasan-gce 2018/04/05 00:40 upstream 3e968c9f1401 676bd07e .config log report
ci-upstream-kasan-gce 2018/04/04 19:40 upstream 17dec0a94915 676bd07e .config log report
ci-upstream-kasan-gce-386 2018/04/12 07:40 upstream f2d285669aae 9cd56d71 .config log report
ci-upstream-kasan-gce-386 2018/04/11 19:31 upstream f2d285669aae 8b8de427 .config log report
ci-upstream-kasan-gce-386 2018/04/10 16:34 upstream f2d285669aae 8e873e9d .config log report
ci-upstream-kasan-gce-386 2018/04/10 05:55 upstream f2d285669aae b9f65507 .config log report
ci-upstream-kasan-gce-386 2018/04/10 03:51 upstream f2d285669aae b9f65507 .config log report
ci-upstream-kasan-gce-386 2018/04/09 19:38 upstream f2d285669aae f13fb445 .config log report
ci-upstream-kasan-gce-386 2018/04/09 03:37 upstream f2d285669aae 77bd5117 .config log report
ci-upstream-kasan-gce-386 2018/04/08 22:25 upstream f2d285669aae 77bd5117 .config log report
ci-upstream-kasan-gce-386 2018/04/08 05:07 upstream f2d285669aae 66f22a7f .config log report
ci-upstream-kasan-gce-386 2018/04/07 18:50 upstream f2d285669aae 66f22a7f .config log report
ci-upstream-kasan-gce-386 2018/04/07 06:32 upstream f2d285669aae d613535f .config log report
ci-upstream-kasan-gce-386 2018/04/07 05:00 upstream f2d285669aae d613535f .config log report
ci-upstream-kasan-gce-386 2018/04/07 01:06 upstream f2d285669aae d613535f .config log report
ci-upstream-kasan-gce-386 2018/04/06 06:16 upstream f2d285669aae a932eae6 .config log report
ci-upstream-kasan-gce-386 2018/04/05 14:39 upstream f2d285669aae 5e1ccffc .config log report
* Struck through repros no longer work on HEAD.