INFO: task syz.4.221:7288 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.221       state:D stack:28808 pid:7288  tgid:7250  ppid:6385   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 path_openat+0x8da/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbf4738ec29
RSP: 002b:00007fbf48234038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbf475d6090 RCX: 00007fbf4738ec29
RDX: 0000000000143442 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007fbf47411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbf475d6128 R14: 00007fbf475d6090 R15: 00007ffe9cd99cd8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
5 locks held by kworker/u10:1/36:
 #0: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff888136624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffff888136625918 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30
 #3: ffffffff99cfa110 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xbb/0x420
 #4: ffff888136624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
2 locks held by getty/5680:
 #0: ffff88810f05f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u8:3/5882:
 #0: ffff88810fa53148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900034efbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
3 locks held by kworker/1:4/5903:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003a7fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88801fad3240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180
5 locks held by syz.4.221/7251:
 #0: ffff8880337a8428 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888021562ed8 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: path_openat+0x8da/0x3830
 #2: ffff8880215632c0 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90
 #3: ffff888038204398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220
 #4: ffff888038226710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0
2 locks held by syz.4.221/7288:
 #0: ffff8880337a8428 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888021562ed8 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: path_openat+0x8da/0x3830
2 locks held by dhcpcd/8009:
 #0: ffff88802b5ce808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz-executor/10559:
 #0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.3.694/10674:
 #0: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
1 lock held by rm/10693:

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

NMI backtrace for cpu 1
CPU: 1 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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 5882 Comm: kworker/u8:3 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: bat_events batadv_nc_worker
RIP: 0010:debug_smp_processor_id+0x0/0x20
Code: c7 40 39 1f 8e 4c 89 f6 e8 6d 63 85 f9 e9 66 ff ff ff cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 c7 c7 20 3f e3 8b 48 c7 c6 60 3f e3 8b eb 1c 66 66
RSP: 0018:ffffc900034ef898 EFLAGS: 00000083
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81c755f8
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fa3a730
RBP: ffffc900034ef978 R08: ffffffff8fa3a737 R09: 1ffffffff1f474e6
R10: dffffc0000000000 R11: fffffbfff1f474e7 R12: ffffffff8b4845e8
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200069df1c
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4f3b3c440 CR3: 000000010efba000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_is_watching+0x15/0xb0
 trace_irq_enable+0x37/0x110
 trace_hardirqs_on+0x18/0x40
 __local_bh_enable_ip+0x12d/0x1c0
 batadv_nc_purge_paths+0x318/0x3b0
 batadv_nc_worker+0x369/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
