INFO: task syz.2.8927:28462 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.8927      state:D stack:27872 pid:28462 tgid:28461 ppid:24819  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 bdev_open+0xe0/0xd30
 bdev_file_open_by_dev+0x1be/0x240
 setup_bdev_super+0x5a/0x5b0
 get_tree_bdev_flags+0x389/0x4f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x341/0xd30
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f38d259cdd9
RSP: 002b:00007f38d3487028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f38d2815fa0 RCX: 00007f38d259cdd9
RDX: 0000200000000040 RSI: 00002000000004c0 RDI: 0000200000000480
RBP: 00007f38d2632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000008205 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f38d2816038 R14: 00007f38d2815fa0 R15: 00007ffe2c641678
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5439:
 #0: ffff8881168d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/10895:
 #0: ffff88810b3dd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by syz.2.8927/28462:
 #0: ffff8881bbd7a0d8 (&type->s_umount_key#136/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0
 #1: ffff88810b3dd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 5049 Comm: klogd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:stack_trace_consume_entry+0x0/0x280
Code: f0 5b 41 5e 5d c3 cc cc cc cc cc e8 fa 1a f7 09 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 ba 00 00
RSP: 0018:ffffc90003477440 EFLAGS: 00000286
RAX: ffffffff8971f24e RBX: ffffc90003477500 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8971f24e RDI: ffffc90003477500
RBP: ffffc900034774d0 R08: ffffc90003477ea0 R09: 0000000000000000
R10: ffffc90003477498 R11: ffffffff81b0d910 R12: ffff88816ae6d880
R13: 00000000000000f0 R14: ffffffff81b0d910 R15: ffffc90003477448
FS:  00007f956291a380(0000) GS:ffff88818dc93000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30e12ff8 CR3: 0000000117a92000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 arch_stack_walk+0x10f/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x384/0x690
 __alloc_skb+0x1d0/0x7d0
 alloc_skb_with_frags+0xc8/0x760
 sock_alloc_send_pskb+0x878/0x990
 unix_dgram_sendmsg+0x460/0x18d0
 __sys_sendto+0x672/0x710
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9562a7c9b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffcf8cbea08 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f9562a7c9b5
RDX: 0000000000000052 RSI: 0000560865d07c30 RDI: 0000000000000003
RBP: 0000560865cff910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007f9562c0a212 R14: 00007ffcf8cbeb08 R15: 0000000000000000
 </TASK>
