text: TITLE: INFO: task hung in mount_bdev
  TYPE: HANG
  
  [  767.964958][ T1042] INFO: task syz-executor013:7561 blocked for more than 143 seconds.
  [  767.973200][ T1042]       Not tainted 5.1.0-rc6+ #90
  [  767.978361][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  767.987323][ T1042] syz-executor013 D29336  7561   7543 0x00000004
  [  767.993661][ T1042] Call Trace:
  [  767.997133][ T1042]  __schedule+0x813/0x1cc0
  [  768.014473][ T1042]  schedule+0x92/0x180
  [  768.020552][ T1042]  schedule_preempt_disabled+0x13/0x20
  [  768.027010][ T1042]  __mutex_lock+0x726/0x1310
  [  768.051197][ T1042]  mutex_lock_nested+0x16/0x20
  [  768.061122][ T1042]  mount_bdev+0x93/0x3c0
  [  768.075747][ T1042]  udf_mount+0x35/0x40
  [  768.085482][ T1042]  legacy_get_tree+0xf2/0x200
  [  768.096701][ T1042]  vfs_get_tree+0x123/0x450
  [  768.101589][ T1042]  do_mount+0x1436/0x2c40
  [  768.127663][ T1042]  ksys_mount+0xdb/0x150
  [  768.132136][ T1042]  __x64_sys_mount+0xbe/0x150
  [  768.136893][ T1042]  do_syscall_64+0x103/0x610
  [  768.141633][ T1042]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  768.147568][ T1042] RIP: 0033:0x44a739
  [  768.151707][ T1042] Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  [  768.172294][ T1042] RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  [  768.180755][ T1042] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  [  768.188912][ T1042] RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  [  768.196921][ T1042] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  [  768.205082][ T1042] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  [  768.213067][ T1042] R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  [  768.221103][ T1042] INFO: task syz-executor013:7563 blocked for more than 143 seconds.
  [  768.229355][ T1042]       Not tainted 5.1.0-rc6+ #90
  [  768.234452][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  768.243162][ T1042] syz-executor013 D29720  7563   7541 0x00000004
  [  768.249679][ T1042] Call Trace:
  [  768.252972][ T1042]  __schedule+0x813/0x1cc0
  [  768.267246][ T1042]  schedule+0x92/0x180
  [  768.271455][ T1042]  schedule_preempt_disabled+0x13/0x20
  [  768.276960][ T1042]  __mutex_lock+0x726/0x1310
  [  768.301820][ T1042]  mutex_lock_nested+0x16/0x20
  [  768.311709][ T1042]  mount_bdev+0x93/0x3c0
  [  768.326135][ T1042]  udf_mount+0x35/0x40
  [  768.335859][ T1042]  legacy_get_tree+0xf2/0x200
  [  768.347058][ T1042]  vfs_get_tree+0x123/0x450
  [  768.351780][ T1042]  do_mount+0x1436/0x2c40
  [  768.377854][ T1042]  ksys_mount+0xdb/0x150
  [  768.382226][ T1042]  __x64_sys_mount+0xbe/0x150
  [  768.386954][ T1042]  do_syscall_64+0x103/0x610
  [  768.391686][ T1042]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  768.397620][ T1042] RIP: 0033:0x44a739
  [  768.401661][ T1042] Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  [  768.425721][ T1042] RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  [  768.434131][ T1042] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  [  768.442159][ T1042] RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  [  768.450311][ T1042] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  [  768.458340][ T1042] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  [  768.466471][ T1042] R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  [  768.474468][ T1042] INFO: task syz-executor013:7559 blocked for more than 143 seconds.
  [  768.482591][ T1042]       Not tainted 5.1.0-rc6+ #90
  [  768.487887][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  768.496604][ T1042] syz-executor013 D29096  7559   7544 0x00000004
  [  768.503084][ T1042] Call Trace:
  [  768.506426][ T1042]  __schedule+0x813/0x1cc0
  [  768.532461][ T1042]  schedule+0x92/0x180
  [  768.536599][ T1042]  rwsem_down_write_failed+0x774/0xc30
  [  768.552726][ T1042]  call_rwsem_down_write_failed+0x17/0x30
  [  768.565335][ T1042]  down_write+0x53/0x90
  [  768.574050][ T1042]  grab_super+0xb4/0x290
  [  768.598508][ T1042]  sget_userns+0x1ab/0x560
  [  768.618257][ T1042]  sget+0x10c/0x150
  [  768.622213][ T1042]  mount_bdev+0xff/0x3c0
  [  768.631400][ T1042]  udf_mount+0x35/0x40
  [  768.641676][ T1042]  legacy_get_tree+0xf2/0x200
  [  768.652778][ T1042]  vfs_get_tree+0x123/0x450
  [  768.657331][ T1042]  do_mount+0x1436/0x2c40
  [  768.683418][ T1042]  ksys_mount+0xdb/0x150
  [  768.688581][ T1042]  __x64_sys_mount+0xbe/0x150
  [  768.693263][ T1042]  do_syscall_64+0x103/0x610
  [  768.697905][ T1042]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  768.703939][ T1042] RIP: 0033:0x44a739
  [  768.707867][ T1042] Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  [  768.727665][ T1042] RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  [  768.736116][ T1042] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  [  768.744225][ T1042] RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  [  768.752255][ T1042] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  [  768.760408][ T1042] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  [  768.768434][ T1042] R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  [  768.776604][ T1042] INFO: task syz-executor013:7565 blocked for more than 144 seconds.
  [  768.784665][ T1042]       Not tainted 5.1.0-rc6+ #90
  [  768.789817][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  768.798628][ T1042] syz-executor013 D29720  7565   7542 0x00000004
  [  768.805023][ T1042] Call Trace:
  [  768.808446][ T1042]  __schedule+0x813/0x1cc0
  [  768.824670][ T1042]  schedule+0x92/0x180
  [  768.828797][ T1042]  schedule_preempt_disabled+0x13/0x20
  [  768.834395][ T1042]  __mutex_lock+0x726/0x1310
  [  768.858495][ T1042]  mutex_lock_nested+0x16/0x20
  [  768.868373][ T1042]  mount_bdev+0x93/0x3c0
  [  768.883017][ T1042]  udf_mount+0x35/0x40
  [  768.892748][ T1042]  legacy_get_tree+0xf2/0x200
  [  768.903904][ T1042]  vfs_get_tree+0x123/0x450
  [  768.908456][ T1042]  do_mount+0x1436/0x2c40
  [  768.934426][ T1042]  ksys_mount+0xdb/0x150
  [  768.938706][ T1042]  __x64_sys_mount+0xbe/0x150
  [  768.943534][ T1042]  do_syscall_64+0x103/0x610
  [  768.949064][ T1042]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  768.955007][ T1042] RIP: 0033:0x44a739
  [  768.959046][ T1042] Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  [  768.978703][ T1042] RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  [  768.987283][ T1042] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  [  768.995519][ T1042] RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  [  769.003491][ T1042] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  [  769.011744][ T1042] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  [  769.019970][ T1042] R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  [  769.028216][ T1042] INFO: task syz-executor013:7562 blocked for more than 144 seconds.
  [  769.036488][ T1042]       Not tainted 5.1.0-rc6+ #90
  [  769.041593][ T1042] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [  769.050508][ T1042] syz-executor013 D29720  7562   7546 0x00000004
  [  769.057086][ T1042] Call Trace:
  [  769.060405][ T1042]  __schedule+0x813/0x1cc0
  [  769.074730][ T1042]  schedule+0x92/0x180
  [  769.079874][ T1042]  schedule_preempt_disabled+0x13/0x20
  [  769.085567][ T1042]  __mutex_lock+0x726/0x1310
  [  769.109790][ T1042]  mutex_lock_nested+0x16/0x20
  [  769.119731][ T1042]  mount_bdev+0x93/0x3c0
  [  769.134260][ T1042]  udf_mount+0x35/0x40
  [  769.144069][ T1042]  legacy_get_tree+0xf2/0x200
  [  769.155565][ T1042]  vfs_get_tree+0x123/0x450
  [  769.160068][ T1042]  do_mount+0x1436/0x2c40
  [  769.186353][ T1042]  ksys_mount+0xdb/0x150
  [  769.190596][ T1042]  __x64_sys_mount+0xbe/0x150
  [  769.195513][ T1042]  do_syscall_64+0x103/0x610
  [  769.200101][ T1042]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  769.207055][ T1042] RIP: 0033:0x44a739
  [  769.210958][ T1042] Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  [  769.230833][ T1042] RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  [  769.239504][ T1042] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  [  769.247745][ T1042] RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  [  769.255934][ T1042] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  [  769.263903][ T1042] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  [  769.272144][ T1042] R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  [  769.280357][ T1042] 
  [  769.280357][ T1042] Showing all locks held in the system:
  [  769.288320][ T1042] 1 lock held by khungtaskd/1042:
  [  769.293332][ T1042]  #0: 000000006329251d (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e
  [  769.303003][ T1042] 1 lock held by rsyslogd/7425:
  [  769.308092][ T1042]  #0: 00000000d77ddd95 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
  [  769.316994][ T1042] 2 locks held by getty/7515:
  [  769.321658][ T1042]  #0: 000000004c45b4e6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.330857][ T1042]  #1: 00000000cb1f5c30 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.341530][ T1042] 2 locks held by getty/7516:
  [  769.346430][ T1042]  #0: 0000000061e5eac7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.355629][ T1042]  #1: 00000000aab03c35 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.365512][ T1042] 2 locks held by getty/7517:
  [  769.370176][ T1042]  #0: 00000000205ee5b4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.379359][ T1042]  #1: 0000000002712bdb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.389227][ T1042] 2 locks held by getty/7518:
  [  769.393891][ T1042]  #0: 000000000cc046b2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.408494][ T1042]  #1: 00000000d5140a4a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.418291][ T1042] 2 locks held by getty/7519:
  [  769.422966][ T1042]  #0: 000000003624da6d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.432226][ T1042]  #1: 00000000f5b16893 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.442027][ T1042] 2 locks held by getty/7520:
  [  769.446931][ T1042]  #0: 0000000082294f91 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.456132][ T1042]  #1: 00000000870dfcb5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.466699][ T1042] 2 locks held by getty/7521:
  [  769.472073][ T1042]  #0: 000000000f72fa86 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
  [  769.481384][ T1042]  #1: 00000000a044b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  [  769.491648][ T1042] 2 locks held by syz-executor013/7547:
  [  769.497458][ T1042] 1 lock held by syz-executor013/7561:
  [  769.502908][ T1042]  #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  [  769.512707][ T1042] 1 lock held by syz-executor013/7563:
  [  769.518395][ T1042]  #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  [  769.528048][ T1042] 2 locks held by syz-executor013/7559:
  [  769.533585][ T1042]  #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  [  769.543245][ T1042]  #1: 000000001ecfe564 (&type->s_umount_key#39){+.+.}, at: grab_super+0xb4/0x290
  [  769.552721][ T1042] 1 lock held by syz-executor013/7565:
  [  769.558422][ T1042]  #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  [  769.568068][ T1042] 1 lock held by syz-executor013/7562:
  [  769.573513][ T1042]  #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  [  769.583183][ T1042] 
  [  769.585751][ T1042] =============================================
  [  769.585751][ T1042] 
  [  769.594153][ T1042] NMI backtrace for cpu 1
  [  769.598535][ T1042] CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc6+ #90
  [  769.606068][ T1042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  [  769.616138][ T1042] Call Trace:
  [  769.619493][ T1042]  dump_stack+0x172/0x1f0
  [  769.623825][ T1042]  nmi_cpu_backtrace.cold+0x63/0xa4
  [  769.634703][ T1042]  nmi_trigger_cpumask_backtrace+0x1be/0x236
  [  769.640680][ T1042]  arch_trigger_cpumask_backtrace+0x14/0x20
  [  769.646575][ T1042]  watchdog+0x9b7/0xec0
  [  769.650818][ T1042]  kthread+0x357/0x430
  [  769.666665][ T1042]  ret_from_fork+0x3a/0x50
  [  769.671151][ T1042] Sending NMI from CPU 1 to CPUs 0:
  [  769.677189][    C0] NMI backtrace for cpu 0
  [  769.677194][    C0] CPU: 0 PID: 7547 Comm: syz-executor013 Not tainted 5.1.0-rc6+ #90
  [  769.677200][    C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  [  769.677204][    C0] RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50
  [  769.677215][    C0] Code: 25 b4 7e ec 08 41 bc f4 ff ff ff e8 cd 5d ea ff 48 c7 05 9e 7e ec 08 00 00 00 00 e9 a4 e9 ff ff 90 90 90 90 90 90 90 90 90 55 <48> 89 e5 48 8b 75 08 65 48 8b 04 25 00 ee 01 00 65 8b 15 c8 60 91
  [  769.677219][    C0] RSP: 0018:ffff8880973ef470 EFLAGS: 00000246
  [  769.677226][    C0] RAX: 0000000000000000 RBX: ffff8880973ef568 RCX: ffffffff870d9383
  [  769.677231][    C0] RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007
  [  769.677235][    C0] RBP: ffff8880973ef4b0 R08: ffff88808c9fe080 R09: ffffed1015d05bc8
  [  769.677240][    C0] R10: ffffed1015d05bc7 R11: ffff8880ae82de3b R12: ffff8880a0dc9442
  [  769.677245][    C0] R13: ffff8880973ef580 R14: 0000000000000138 R15: ffff8880a0dc9442
  [  769.677250][    C0] FS:  00007f9541ef1700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
  [  769.677254][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [  769.677258][    C0] CR2: 0000000000c02000 CR3: 00000000a9780000 CR4: 00000000001406f0
  [  769.677263][    C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [  769.677268][    C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [  769.677270][    C0] Call Trace:
  [  769.677276][    C0]  xas_load+0x21/0x150
  [  769.677283][    C0]  find_get_entry+0x13d/0x880
  [  769.677296][    C0]  pagecache_get_page+0x4c/0x740
  [  769.677299][    C0]  __find_get_block+0x501/0xcf0
  [  769.677306][    C0]  __getblk_gfp+0x1b1/0x970
  [  769.677309][    C0]  __bread_gfp+0x2f/0x300
  [  769.677312][    C0]  udf_tread+0xf1/0x140
  [  769.677315][    C0]  udf_read_tagged+0x50/0x530
  [  769.677318][    C0]  udf_check_anchor_block+0x1ef/0x680
  [  769.677331][    C0]  udf_scan_anchors+0x1cf/0x680
  [  769.677346][    C0]  udf_load_vrs+0x8bf/0xc80
  [  769.677358][    C0]  udf_fill_super+0x7d8/0x16d1
  [  769.677374][    C0]  mount_bdev+0x307/0x3c0
  [  769.677379][    C0]  udf_mount+0x35/0x40
  [  769.677385][    C0]  legacy_get_tree+0xf2/0x200
  [  769.677391][    C0]  vfs_get_tree+0x123/0x450
  [  769.677394][    C0]  do_mount+0x1436/0x2c40
  [  769.677409][    C0]  ksys_mount+0xdb/0x150
  [  769.677412][    C0]  __x64_sys_mount+0xbe/0x150
  [  769.677415][    C0]  do_syscall_64+0x103/0x610
  [  769.677418][    C0]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  769.677421][    C0] RIP: 0033:0x44a739
  [  769.677438][    C0] Code: 4d cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00
  [  769.677442][    C0] RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  [  769.677454][    C0] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  [  769.677458][    C0] RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  [  769.677462][    C0] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  [  769.677467][    C0] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  [  769.677471][    C0] R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  [  769.680389][ T1042] Kernel panic - not syncing: hung_task: blocked tasks
  [  770.124041][ T1042] CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc6+ #90
  [  770.131570][ T1042] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  [  770.141616][ T1042] Call Trace:
  [  770.144926][ T1042]  dump_stack+0x172/0x1f0
  [  770.149350][ T1042]  panic+0x2cb/0x65c
  [  770.193147][ T1042]  watchdog+0x9c8/0xec0
  [  770.197301][ T1042]  kthread+0x357/0x430
  [  770.213167][ T1042]  ret_from_fork+0x3a/0x50
  [  770.219050][ T1042] Kernel Offset: disabled
  [  770.223376][ T1042] Rebooting in 86400 seconds..
  
  REPORT:
  INFO: task syz-executor013:7561 blocked for more than 143 seconds.
        Not tainted 5.1.0-rc6+ #90
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  syz-executor013 D29336  7561   7543 0x00000004
  Call Trace:
   __schedule+0x813/0x1cc0
   schedule+0x92/0x180
   schedule_preempt_disabled+0x13/0x20
   __mutex_lock+0x726/0x1310
   mutex_lock_nested+0x16/0x20
   mount_bdev+0x93/0x3c0
   udf_mount+0x35/0x40
   legacy_get_tree+0xf2/0x200
   vfs_get_tree+0x123/0x450
   do_mount+0x1436/0x2c40
   ksys_mount+0xdb/0x150
   __x64_sys_mount+0xbe/0x150
   do_syscall_64+0x103/0x610
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x44a739
  Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  INFO: task syz-executor013:7563 blocked for more than 143 seconds.
        Not tainted 5.1.0-rc6+ #90
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  syz-executor013 D29720  7563   7541 0x00000004
  Call Trace:
   __schedule+0x813/0x1cc0
   schedule+0x92/0x180
   schedule_preempt_disabled+0x13/0x20
   __mutex_lock+0x726/0x1310
   mutex_lock_nested+0x16/0x20
   mount_bdev+0x93/0x3c0
   udf_mount+0x35/0x40
   legacy_get_tree+0xf2/0x200
   vfs_get_tree+0x123/0x450
   do_mount+0x1436/0x2c40
   ksys_mount+0xdb/0x150
   __x64_sys_mount+0xbe/0x150
   do_syscall_64+0x103/0x610
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x44a739
  Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  INFO: task syz-executor013:7559 blocked for more than 143 seconds.
        Not tainted 5.1.0-rc6+ #90
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  syz-executor013 D29096  7559   7544 0x00000004
  Call Trace:
   __schedule+0x813/0x1cc0
   schedule+0x92/0x180
   rwsem_down_write_failed+0x774/0xc30
   call_rwsem_down_write_failed+0x17/0x30
   down_write+0x53/0x90
   grab_super+0xb4/0x290
   sget_userns+0x1ab/0x560
   sget+0x10c/0x150
   mount_bdev+0xff/0x3c0
   udf_mount+0x35/0x40
   legacy_get_tree+0xf2/0x200
   vfs_get_tree+0x123/0x450
   do_mount+0x1436/0x2c40
   ksys_mount+0xdb/0x150
   __x64_sys_mount+0xbe/0x150
   do_syscall_64+0x103/0x610
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x44a739
  Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  INFO: task syz-executor013:7565 blocked for more than 144 seconds.
        Not tainted 5.1.0-rc6+ #90
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  syz-executor013 D29720  7565   7542 0x00000004
  Call Trace:
   __schedule+0x813/0x1cc0
   schedule+0x92/0x180
   schedule_preempt_disabled+0x13/0x20
   __mutex_lock+0x726/0x1310
   mutex_lock_nested+0x16/0x20
   mount_bdev+0x93/0x3c0
   udf_mount+0x35/0x40
   legacy_get_tree+0xf2/0x200
   vfs_get_tree+0x123/0x450
   do_mount+0x1436/0x2c40
   ksys_mount+0xdb/0x150
   __x64_sys_mount+0xbe/0x150
   do_syscall_64+0x103/0x610
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x44a739
  Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  INFO: task syz-executor013:7562 blocked for more than 144 seconds.
        Not tainted 5.1.0-rc6+ #90
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  syz-executor013 D29720  7562   7546 0x00000004
  Call Trace:
   __schedule+0x813/0x1cc0
   schedule+0x92/0x180
   schedule_preempt_disabled+0x13/0x20
   __mutex_lock+0x726/0x1310
   mutex_lock_nested+0x16/0x20
   mount_bdev+0x93/0x3c0
   udf_mount+0x35/0x40
   legacy_get_tree+0xf2/0x200
   vfs_get_tree+0x123/0x450
   do_mount+0x1436/0x2c40
   ksys_mount+0xdb/0x150
   __x64_sys_mount+0xbe/0x150
   do_syscall_64+0x103/0x610
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x44a739
  Code: 00 49 6e 76 61 6c 69 64 20 22 24 41 63 74 69 6f 6e 51 75 65 75 65 43 68 65 63 6b 70 6f 69 6e 74 49 6e 74 65 72 76 61 6c 22 2c <20> 65 72 72 6f 72 20 25 64 2e 20 49 67 6e 6f 72 65 64 2c 20 72 75
  RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  
  Showing all locks held in the system:
  1 lock held by khungtaskd/1042:
   #0: 000000006329251d (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e
  1 lock held by rsyslogd/7425:
   #0: 00000000d77ddd95 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
  2 locks held by getty/7515:
   #0: 000000004c45b4e6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 00000000cb1f5c30 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by getty/7516:
   #0: 0000000061e5eac7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 00000000aab03c35 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by getty/7517:
   #0: 00000000205ee5b4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 0000000002712bdb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by getty/7518:
   #0: 000000000cc046b2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 00000000d5140a4a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by getty/7519:
   #0: 000000003624da6d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 00000000f5b16893 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by getty/7520:
   #0: 0000000082294f91 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 00000000870dfcb5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by getty/7521:
   #0: 000000000f72fa86 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40
   #1: 00000000a044b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70
  2 locks held by syz-executor013/7547:
  1 lock held by syz-executor013/7561:
   #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  1 lock held by syz-executor013/7563:
   #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  2 locks held by syz-executor013/7559:
   #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
   #1: 000000001ecfe564 (&type->s_umount_key#39){+.+.}, at: grab_super+0xb4/0x290
  1 lock held by syz-executor013/7565:
   #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  1 lock held by syz-executor013/7562:
   #0: 00000000d97cb347 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0
  
  =============================================
  
  NMI backtrace for cpu 1
  CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc6+ #90
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
   dump_stack+0x172/0x1f0
   nmi_cpu_backtrace.cold+0x63/0xa4
   nmi_trigger_cpumask_backtrace+0x1be/0x236
   arch_trigger_cpumask_backtrace+0x14/0x20
   watchdog+0x9b7/0xec0
   kthread+0x357/0x430
   ret_from_fork+0x3a/0x50
  Sending NMI from CPU 1 to CPUs 0:
  NMI backtrace for cpu 0
  CPU: 0 PID: 7547 Comm: syz-executor013 Not tainted 5.1.0-rc6+ #90
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50
  Code: 25 b4 7e ec 08 41 bc f4 ff ff ff e8 cd 5d ea ff 48 c7 05 9e 7e ec 08 00 00 00 00 e9 a4 e9 ff ff 90 90 90 90 90 90 90 90 90 55 <48> 89 e5 48 8b 75 08 65 48 8b 04 25 00 ee 01 00 65 8b 15 c8 60 91
  RSP: 0018:ffff8880973ef470 EFLAGS: 00000246
  RAX: 0000000000000000 RBX: ffff8880973ef568 RCX: ffffffff870d9383
  RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007
  RBP: ffff8880973ef4b0 R08: ffff88808c9fe080 R09: ffffed1015d05bc8
  R10: ffffed1015d05bc7 R11: ffff8880ae82de3b R12: ffff8880a0dc9442
  R13: ffff8880973ef580 R14: 0000000000000138 R15: ffff8880a0dc9442
  FS:  00007f9541ef1700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000c02000 CR3: 00000000a9780000 CR4: 00000000001406f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   xas_load+0x21/0x150
   find_get_entry+0x13d/0x880
   pagecache_get_page+0x4c/0x740
   __find_get_block+0x501/0xcf0
   __getblk_gfp+0x1b1/0x970
   __bread_gfp+0x2f/0x300
   udf_tread+0xf1/0x140
   udf_read_tagged+0x50/0x530
   udf_check_anchor_block+0x1ef/0x680
   udf_scan_anchors+0x1cf/0x680
   udf_load_vrs+0x8bf/0xc80
   udf_fill_super+0x7d8/0x16d1
   mount_bdev+0x307/0x3c0
   udf_mount+0x35/0x40
   legacy_get_tree+0xf2/0x200
   vfs_get_tree+0x123/0x450
   do_mount+0x1436/0x2c40
   ksys_mount+0xdb/0x150
   __x64_sys_mount+0xbe/0x150
   do_syscall_64+0x103/0x610
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x44a739
  Code: 4d cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00
  RSP: 002b:00007f9541ef0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a739
  RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000080
  RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
  R13: 00007ffc6cf3cddf R14: 00007f9541ef19c0 R15: 0000000000000000
  