INFO: task syz.2.4350:24447 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.4350      state:D stack:22712 pid:24447 tgid:24446 ppid:5845   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x9a/0x270
 wait_for_completion+0x2bf/0x5d0
 disable_device+0x1c6/0x320
 __ib_unregister_device+0x2cb/0x3f0
 ib_unregister_device_and_put+0xb8/0xf0
 nldev_dellink+0x2d1/0x320
 rdma_nl_rcv+0x6ae/0x980
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3cd398eba9
RSP: 002b:00007f3cd4803038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3cd3bd5fa0 RCX: 00007f3cd398eba9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000008
RBP: 00007f3cd3a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3cd3bd6038 R14: 00007f3cd3bd5fa0 R15: 00007ffe7654e688
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5676:
 #0: ffff88810e8590a0 (&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
4 locks held by kworker/u8:2/5743:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002ecfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52c450 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff888123bc0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by sshd/5773:
2 locks held by syz.2.4350/24447:
 #0: ffffffff99e6a918 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888123bc0700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.4.4381/24574:
 #0: ffffffff8f52c450 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888123bc0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.4381/24575:
 #0: ffffffff8f52c450 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888123bc0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.5231/28375:
 #0: ffffffff8f52c450 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888123bc0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.5479/29478:
 #0: ffffffff8f52c450 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888123bc0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.5684/30361:
 #0: ffff88806c51e808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240
 #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
3 locks held by syz.8.5688/30392:
 #0: ffffffff8fa3cef8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f539308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #2: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

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+0x3fc/0x770
 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: 12 Comm: kworker/u8:0 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: bat_events batadv_nc_worker
RIP: 0010:__local_bh_enable_ip+0x14e/0x1c0
Code: 78 15 0b 00 e8 f3 6f 42 00 fb 65 8b 05 fb 97 1b 11 85 c0 75 05 e8 b2 de ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 00 00 00 <65> 48 8b 05 ca 97 1b 11 48 3b 44 24 48 75 57 48 8d 65 e0 5b 41 5c
RSP: 0018:ffffc900000f78e0 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 0000000000000201 RCX: 71599a4f9fab7e00
RDX: 0000000000000006 RSI: ffffffff8d9b8d8d RDI: ffffffff8be33880
RBP: ffffc900000f7978 R08: ffffffff8fa39837 R09: 1ffffffff1f47306
R10: dffffc0000000000 R11: fffffbfff1f47307 R12: ffffffff8b47ff48
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200001ef1c
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83aa887e20 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
