INFO: task syz.3.27930:11791 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.3.27930     state:D stack:27592 pid:11791 tgid:11790 ppid:8103   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 sync_bdevs+0x27e/0x470
 __ia32_sys_sync+0xc5/0x120
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f626f99cdd9
RSP: 002b:00007f62707a3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f626fc15fa0 RCX: 00007f626f99cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f626fc15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f626fc16038 R14: 00007f626fc15fa0 R15: 00007ffcd24c1368
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5437:
 #0: ffff8881159e90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/28591:
 #0: ffff88816a1ee350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.3.27930/11791:
 #0: ffff88816a1ee350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470
2 locks held by syz.1.29608/15969:
3 locks held by syz.5.29623/16005:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 15969 Comm: syz.1.29608 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+0x4/0x280
Code: 5d c3 cc cc cc cc cc e8 3a 08 f8 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 00 00 00 fc
RSP: 0018:ffffc90009e87400 EFLAGS: 00000282
RAX: ffffffff8253ac45 RBX: ffffc90009e874c0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8253ac45 RDI: ffffc90009e874c0
RBP: ffffc90009e87490 R08: ffffc90009e87bf0 R09: 0000000000000000
R10: ffffc90009e87458 R11: ffffffff81b0ebd0 R12: ffff88810b59d880
R13: 0000000000000000 R14: ffffffff81b0ebd0 R15: ffffc90009e87408
FS:  00007f3f269d26c0(0000) GS:ffff8882a928c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3f1f7ff000 CR3: 000000011d6b4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x10f/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x640
 iter_file_splice_write+0xf81/0x10f0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x53a/0xc70
 do_splice_direct+0x195/0x290
 do_sendfile+0x535/0x7d0
 __se_sys_sendfile64+0x144/0x1a0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f25b9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3f269d2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f3f25e15fa0 RCX: 00007f3f25b9cdd9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007f3f25c32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000003ffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f25e16038 R14: 00007f3f25e15fa0 R15: 00007ffd1f5bdc08
 </TASK>
