INFO: task syz.2.1927:15369 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1927      state:D stack:16920 pid:15369 tgid:15368 ppid:10196  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 __closure_sync+0x163/0x220
 bch2_read_iter+0x1034/0x1440
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe2d778ebe9
RSP: 002b:00007fe2d8689038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fe2d79c5fa0 RCX: 00007fe2d778ebe9
RDX: 0000000000001000 RSI: 0000200000001400 RDI: 0000000000000004
RBP: 00007fe2d7811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe2d79c6038 R14: 00007fe2d79c5fa0 R15: 00007ffdfcc16b48
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/1:0/24:
1 lock held by khungtaskd/34:
 #0: ffffffff8e33cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/1:1/47:
2 locks held by getty/5676:
 #0: ffff8881085810a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000291b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by kworker/1:8/8880:
1 lock held by syz.2.1927/15369:
 #0: ffff88810de78cf8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
3 locks held by syz.5.2305/17580:
 #0: ffff888039e390a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb7/0x200
 #1: ffff888039e3b0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xdb/0x200
 #2: ffffffff8e342700 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
1 lock held by syz.7.2307/17600:

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

NMI backtrace for cpu 0
CPU: 0 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x47f/0x820
 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: 24 Comm: kworker/1:0 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: events_power_efficient neigh_periodic_work
RIP: 0010:unwind_next_frame+0xa9f/0x2390
Code: c0 0f 85 78 13 00 00 49 89 df 49 c1 ef 03 41 0f b6 04 2f 84 c0 0f 85 88 13 00 00 0f b6 76 01 83 e6 07 83 fe 04 4c 89 64 24 10 <0f> 84 49 04 00 00 83 fe 03 0f 84 f3 01 00 00 83 fe 02 0f 85 a1 07
RSP: 0018:ffffc900001e05d8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffffff90532627 RCX: ffffffff8fd743b8
RDX: ffffffff90532622 RSI: 0000000000000002 RDI: ffffffff8c0370a0
RBP: dffffc0000000000 R08: 0000000000000007 R09: ffffffff8173bd85
R10: ffffc900001e0758 R11: fffff5200003c0ed R12: ffffc900001e07a0
R13: ffffc900001e0758 R14: ffffc900001e0708 R15: 1ffffffff20a64c4
FS:  0000000000000000(0000) GS:ffff8881a39fa000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c46a493 CR3: 0000000123398000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x199/0x6d0
 ref_tracker_free+0x4dd/0x7d0
 dst_destroy+0x10f/0x350
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 neigh_periodic_work+0xc28/0xe50
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x47f/0x820
 ret_from_fork_asm+0x1a/0x30
 </TASK>
