INFO: task syz-executor:6023 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21416 pid:6023  tgid:6023  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 sync_inodes_sb+0x1bb/0xa10
 sync_filesystem+0x17a/0x230
 generic_shutdown_super+0x6f/0x2c0
 kill_block_super+0x44/0x90
 xfs_kill_sb+0x15/0x50
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xe9/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29b4390a77
RSP: 002b:00007ffcfdb7f578 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f29b4413d7d RCX: 00007f29b4390a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcfdb7f630
RBP: 00007ffcfdb7f630 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcfdb806c0
R13: 00007f29b4413d7d R14: 0000000000020d17 R15: 00007ffcfdb80700
 </TASK>
INFO: task syz-executor:7280 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21128 pid:7280  tgid:7280  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 sync_inodes_sb+0x1bb/0xa10
 sync_filesystem+0x17a/0x230
 generic_shutdown_super+0x6f/0x2c0
 kill_block_super+0x44/0x90
 xfs_kill_sb+0x15/0x50
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xe9/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9484f90a77
RSP: 002b:00007fff7e577768 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f9485013d7d RCX: 00007f9484f90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff7e577820
RBP: 00007fff7e577820 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff7e5788b0
R13: 00007f9485013d7d R14: 000000000002059a R15: 00007fff7e5788f0
 </TASK>

Showing all locks held in the system:
9 locks held by kworker/u9:0/26:
1 lock held by khungtaskd/35:
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u9:4/3018:
2 locks held by getty/5638:
 #0: ffff88816ba0d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0
 (
&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/6023:
 #0: ffff888116a480e0 (&type->s_umount_key#83){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: 
ffff88816b59c820
 (
&bdi->wb_switch_rwsem
){+.+.}-{4:4}
, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz-executor/7280:
 #0: ffff8881738480e0 (&type->s_umount_key#83){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: 
ffff88816b5ba820
 (
&bdi->wb_switch_rwsem
){+.+.}-{4:4}
, at: sync_inodes_sb+0x19f/0xa10
2 locks held by kworker/u9:6/7904:
 #0: ffff888100089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000a4ffba0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
3 locks held by kworker/0:6/8331:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90005c07ba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810cf35240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
2 locks held by dhcpcd/10042:
 #0: ffff88810ae6e260
 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
 #1: ffffffff8df43138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by dhcpcd/10044:
 #0: ffff8881a9a00260
 (
sk_lock-AF_PACKET
){+.+.}-{0:0}
, at: packet_do_bind+0x32/0xcd0
 #1: 
ffffffff8df43138
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: synchronize_rcu_expedited+0x3b9/0x730

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 26 Comm: kworker/u9:0 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: writeback wb_workfn (flush-7:4)
RIP: 0010:_prb_read_valid+0x231/0xa90
Code: 00 00 e8 42 a6 84 00 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 b3 a3 84 00 4d 8b 2c 24 <48> b8 ff ff ff ff ff ff ff 3f 49 21 c5 48 c7 84 24 b8 00 00 00 00
RSP: 0018:ffffc90000a157e0 EFLAGS: 00000246
RAX: 1ffffffff1bc5a88 RBX: ffffffff8de19400 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de2d440
RBP: ffffc90000a15960 R08: ffffffff8de2d447 R09: 1ffffffff1bc5a88
R10: dffffc0000000000 R11: fffffbfff1bc5a89 R12: ffffffff8de2d440
R13: 800000010000cd58 R14: ffffffff8de9eac0 R15: ffffc90000a15970
FS:  0000000000000000(0000) GS:ffff88818eb36000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffe2940ad8 CR3: 0000000174d2c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 prb_read_valid+0x3c/0x60
 printk_get_next_message+0x15c/0x7b0
 console_flush_all+0x4ca/0xb10
 console_unlock+0xbb/0x190
 vprintk_emit+0x4c5/0x590
 _printk+0xcf/0x120
 _xfs_alert_tag+0x1cb/0x2d0
 xfs_buf_verifier_error+0x150/0x2a0
 xfs_agfl_read_verify+0x165/0x1f0
 __xfs_buf_ioend+0x342/0x6f0
 xfs_buf_iowait+0x167/0x480
 xfs_buf_read_map+0x335/0xa50
 xfs_trans_read_buf_map+0x1d7/0x8e0
 xfs_alloc_read_agfl+0x202/0x410
 xfs_alloc_fix_freelist+0xb93/0x1300
 xfs_alloc_vextent_prepare_ag+0xdb/0x610
 xfs_alloc_vextent_iterate_ags+0x140/0x940
 xfs_alloc_vextent_start_ag+0x388/0x850
 xfs_bmapi_allocate+0x188e/0x2e00
 xfs_bmapi_convert_delalloc+0x7e2/0x1430
 xfs_writeback_range+0x674/0xf70
 iomap_writeback_folio+0xe75/0x1c80
 iomap_writepages+0x162/0x2d0
 xfs_vm_writepages+0x296/0x310
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x145/0xff0
 writeback_sb_inodes+0x6c7/0x1010
 wb_writeback+0x43b/0xaf0
 wb_workfn+0x409/0xef0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
