INFO: task udevd:7491 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:24920 pid:7491  tgid:7491  ppid:5297   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 btrfs_control_ioctl+0x111/0x360
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f255e11ad49
RSP: 002b:00007fff707594b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f255e11ad49
RDX: 00007fff707594c8 RSI: 0000000090009427 RDI: 0000000000000009
RBP: 0000000000000009 R08: 0000559e2dfe36f9 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff7075a508 R14: 0000559e32ffaba0 R15: 00007fff7075b228
 </TASK>
INFO: task syz.0.430:8003 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.430       state:D stack:26728 pid:8003  tgid:8002  ppid:5848   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 bdev_open+0xe0/0xd30
 bdev_file_open_by_dev+0x1be/0x240
 bdev_file_open_by_path+0x1cc/0x4d0
 btrfs_scan_one_device+0xa6/0x650
 btrfs_get_tree+0x433/0x1820
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e9998ebe9
RSP: 002b:00007f5e9a8ed038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5e99bc5fa0 RCX: 00007f5e9998ebe9
RDX: 0000200000000040 RSI: 0000200000000100 RDI: 0000200000000000
RBP: 00007f5e99a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5e99bc6038 R14: 00007f5e99bc5fa0 R15: 00007fff39998e78
 </TASK>
INFO: task udevd:8076 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:25944 pid:8076  tgid:8076  ppid:5297   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 btrfs_control_ioctl+0x111/0x360
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f255e11ad49
RSP: 002b:00007fff707594b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f255e11ad49
RDX: 00007fff707594c8 RSI: 0000000090009427 RDI: 0000000000000009
RBP: 0000000000000009 R08: 0000559e2dfe36f9 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff7075a508 R14: 0000559e32ff3950 R15: 00007fff7075b228
 </TASK>
INFO: task syz.3.448:8089 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.448       state:D stack:25128 pid:8089  tgid:8088  ppid:6215   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 btrfs_get_tree+0x408/0x1820
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f608639038a
RSP: 002b:00007f60871f6e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f60871f6ef0 RCX: 00007f608639038a
RDX: 0000200000000200 RSI: 0000200000005600 RDI: 00007f60871f6eb0
RBP: 0000200000000200 R08: 00007f60871f6ef0 R09: 0000000000000800
R10: 0000000000000800 R11: 0000000000000246 R12: 0000200000005600
R13: 00007f60871f6eb0 R14: 000000000000559e R15: 0000200000000740
 </TASK>
INFO: task syz.4.464:8192 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.464       state:D stack:25128 pid:8192  tgid:8191  ppid:8146   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 btrfs_get_tree+0x408/0x1820
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8c3879038a
RSP: 002b:00007f8c3959ee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8c3959eef0 RCX: 00007f8c3879038a
RDX: 00002000000055c0 RSI: 0000200000000280 RDI: 00007f8c3959eeb0
RBP: 00002000000055c0 R08: 00007f8c3959eef0 R09: 0000000002000898
R10: 0000000002000898 R11: 0000000000000246 R12: 0000200000000280
R13: 00007f8c3959eeb0 R14: 00000000000055ae R15: 0000200000000440
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5677:
 #0: ffff888029b030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/5849:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by udevd/5856:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
2 locks held by kworker/u8:3/5877:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
1 lock held by udevd/5931:
 #0: ffff88802121c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/7491:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
2 locks held by syz.0.430/8003:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
 #1: ffff88802121c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/8076:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by syz.3.448/8089:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by syz.4.464/8192:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by syz.5.502/8387:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by udevd/8446:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by syz.2.512/8448:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by udevd/8463:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by syz.6.525/8511:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by syz.7.528/8545:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by udevd/8546:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by syz.8.534/8587:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by udevd/8617:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by syz.9.548/8756:
 #0: ffff88802121c358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340
1 lock held by udevd/8835:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x111/0x360
1 lock held by syz.1.561/8845:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820
1 lock held by syz.0.565/8856:
 #0: ffffffff8e6e3e88 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x408/0x1820

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5877 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x17/0x120
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 be 9e 26 07 48 89 44 24 08 <65> 8b 05 c6 9e 26 07 65 8b 0d bb 9e 26 07 f7 c1 ff ff ff 7f 74 23
RSP: 0018:ffffc900044ef9c8 EFLAGS: 00000282
RAX: f229790565a17300 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff888020519cc0 RSI: ffffffff8be33860 RDI: ffffffff8be33820
RBP: fffffffffffffe38 R08: 0000000000000000 R09: ffffffff8b475462
R10: dffffc0000000000 R11: fffffbfff1f47207 R12: dffffc0000000000
R13: ffffffff8b475462 R14: ffff888110ad4d80 R15: 0000000000000389
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33320ff8 CR3: 000000006044e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_is_watching+0x15/0xb0
 batadv_nc_worker+0x208/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
