INFO: task udevd:5623 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:23496 pid:5623  tgid:5623  ppid:5041   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5820
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 btrfs_control_ioctl+0x117/0x370
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5de991ad49
RSP: 002b:00007ffc827d23c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5de991ad49
RDX: 00007ffc827d23d8 RSI: 0000000090009427 RDI: 0000000000000009
RBP: 0000000000000009 R08: 0000555b0b72a6f9 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc827d3418 R14: 0000555b1d0c0780 R15: 00007ffc827d4138
 </TASK>
INFO: task udevd:5795 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:24200 pid:5795  tgid:5795  ppid:5041   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5820
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 btrfs_control_ioctl+0x117/0x370
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5de991ad49
RSP: 002b:00007ffc827d23c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5de991ad49
RDX: 00007ffc827d23d8 RSI: 0000000090009427 RDI: 0000000000000009
RBP: 0000000000000009 R08: 0000555b0b72a6f9 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc827d3418 R14: 0000555b1d0c3c10 R15: 00007ffc827d4138
 </TASK>
INFO: task syz.0.2636:21462 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2636      state:D stack:26088 pid:21462 tgid:21460 ppid:21202  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5820
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 bdev_open+0xde/0xd70
 bdev_file_open_by_dev+0x1be/0x240
 bdev_file_open_by_path+0x1da/0x4a0
 btrfs_scan_one_device+0xa8/0x680
 btrfs_get_tree+0x4ec/0x19f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x325/0xb00
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efede59f559
RSP: 002b:00007efedf474028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007efede825fa0 RCX: 00007efede59f559
RDX: 00002000000002c0 RSI: 0000200000000280 RDI: 0000200000000240
RBP: 00007efede636b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efede826038 R14: 00007efede825fa0 R15: 00007ffe5e726958
 </TASK>
INFO: task syz.4.2650:21579 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2650      state:D stack:24616 pid:21579 tgid:21578 ppid:17338  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5820
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 btrfs_get_tree+0x4c1/0x19f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x325/0xb00
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f576ffa07ca
RSP: 002b:00007f5770d83e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5770d83ee0 RCX: 00007f576ffa07ca
RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007f5770d83ea0
RBP: 0000200000005100 R08: 00007f5770d83ee0 R09: 0000000000800810
R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f5770d83ea0 R14: 000000000000510a R15: 0000200000000140
 </TASK>
INFO: task syz.3.2666:21702 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2666      state:D stack:24616 pid:21702 tgid:21701 ppid:19377  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17dd/0x5820
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c4/0x15a0
 btrfs_get_tree+0x4c1/0x19f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x325/0xb00
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ead3a07ca
RSP: 002b:00007f8eae285e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8eae285ee0 RCX: 00007f8ead3a07ca
RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007f8eae285ea0
RBP: 0000200000005100 R08: 00007f8eae285ee0 R09: 0000000000800810
R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f8eae285ea0 R14: 000000000000510a R15: 0000200000000140
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/36: 1, last CPU#0:
 #0: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by getty/5421: 2, on CPU#0:
 #0: ffff88817b52d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034932e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by udevd/5594: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by udevd/5595: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by kworker/u8:2/5622: 4, last CPU#1:
 #0: ffff888178343940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90004dd7c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff888105e9d1c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xd4/0xfc0
 #3: ffffffff8fd588e0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule+0x41f/0xfc0
locks held by udevd/5623: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by udevd/5795: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by udevd/9380: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by udevd/13057: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by udevd/16291: 1, on CPU#1:
 #0: ffff88816c8d2350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70
locks held by syz.0.2636/21462: 2, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
 #1: ffff88816c8d2350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70
locks held by syz.4.2650/21579: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.3.2666/21702: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.5.2668/22438: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.2.2675/22551: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.8.2687/22559: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.1.2699/23217: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by udevd/23230: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by syz.6.2701/23373: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.9.2750/23743: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by udevd/23763: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by syz.7.2759/23901: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by udevd/24040: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by udevd/24041: 1, on CPU#0:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x117/0x370
locks held by syz.0.2776/24189: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.5.2855/25115: 1, on CPU#1:
 #0: ffffffff903eda00 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x4c1/0x19f0
locks held by syz.2.3236/27294: 3, last CPU#1:
 #0: ffff8881932ee988 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500
 #1: ffff88817a45a558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0
 #2: ffff88817a458938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0
locks held by dhcpcd-run-hook/27296: 1, last CPU#0:
 #0: ffff888111c2b440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_maybe_expand+0xcd/0x3b0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd2/0x1030
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8174 Comm: kworker/u10:16 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: wg-kex-wg0 wg_packet_handshake_send_worker
RIP: 0010:debug_check_no_obj_freed+0x166/0x450
Code: 0f 84 39 02 00 00 4d 89 fd 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 4c 89 ff e8 fd 38 4b fd 49 8b 1f <4d> 8d 67 18 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80
RSP: 0018:ffffc900066e75e0 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff888111351380 RCX: dffffc0000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900066e7540
RBP: ffff8881130ec340 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000cdcea8 R12: ffff888111351328
R13: 1ffff1102226a269 R14: 000000000000000a R15: ffff888111351348
FS:  0000000000000000(0000) GS:ffff8882a7cb1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2da24000 CR3: 0000000191598000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 kfree+0x13e/0x650
 skb_release_data+0x82e/0xa80
 __kfree_skb+0x5d/0x210
 send6+0x51d/0x920
 wg_socket_send_skb_to_peer+0x111/0x1d0
 wg_packet_handshake_send_worker+0x204/0x370
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
