INFO: task kworker/u10:4:6146 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:4   state:D stack:19752 pid:6146  tgid:6146  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: ib-unreg-wq ib_unregister_work
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_work+0x19/0x30
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000c7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e13fbb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by rcu_tasks_trace/31:
 #0: ffffffff8e13ae50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0
 #1: ffffffff8e13fbb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5672:
 #0: ffff8881064710a0 (&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/u8:5/5886:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000461fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d350 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8e13fa80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
3 locks held by kworker/u10:4/6146:
 #0: ffff88801bfd2948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000649fbc0 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888123e48700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by kworker/u9:18/8031:
 #0: ffff88801a489948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006a57bc0 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
3 locks held by kworker/u9:20/8033:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900067afbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by syz.1.1108/10268:
 #0: ffffffff99e6f8f8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888123e48700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.0.1176/10525:
 #0: ffffffff8f52d350 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888123e48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.1194/10643:
 #0: ffffffff8f52d350 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888123e48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by syz.6.1605/12422:
 #0: ffffffff8e19d6c8 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150
1 lock held by syz.7.1607/12428:
 #0: ffffffff8e19d6c8 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150
2 locks held by syz-executor/12433:
 #0: ffffffff8eca9820 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
1 lock held by syz-executor/12440:
 #0: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/12442:
 #0: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

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

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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 12412 Comm: syz.8.1602 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
RIP: 0010:check_preemption_disabled+0x49/0x120
Code: 8b 0d bb 5e 26 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b 5e 26 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> e9 81 ca 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24
RSP: 0018:ffffc900001df5c0 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000202 RCX: a1e107edd2c88a00
RDX: 0000000000000003 RSI: ffffffff8dba9858 RDI: ffffffff8be33e00
RBP: ffff88801fbba828 R08: ffffc900001dff38 R09: 0000000000000000
R10: ffffc900001df758 R11: fffff5200003beed R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff8e13a120 R15: ffff88801fbb9cc0
FS:  00007f29e85cd6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9cc2f056c0 CR3: 000000012c98e000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_release+0x27a/0x3e0
 unwind_next_frame+0x19a9/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 tcp_ack+0x1fd2/0x6150
 tcp_rcv_established+0xe96/0x1eb0
 tcp_v4_do_rcv+0xa23/0xce0
 tcp_v4_rcv+0x26a6/0x2f40
 ip_protocol_deliver_rcu+0x221/0x440
 ip_local_deliver_finish+0x3bb/0x6f0
 NF_HOOK+0x30c/0x3a0
 ip_sublist_rcv_finish+0x221/0x2a0
 ip_sublist_rcv+0x6e7/0x9b0
 ip_list_rcv+0x3e2/0x430
 __netif_receive_skb_list_core+0x7d2/0x800
 netif_receive_skb_list_internal+0x975/0xcc0
 napi_complete_done+0x2f2/0x7c0
 e1000_clean+0xd0b/0x2b00
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__schedule+0x1a2/0x4cc0
Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 16 0f a8 f6 48 8b 1b 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 48 89 df e8 f4 0e a8 f6 48 81 3b 9d 6e ac 57 0f 85 b7 18 00
RSP: 0018:ffffc900031cf8a0 EFLAGS: 00000246
RAX: 1ffff92000639000 RBX: ffffc900031c8000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8be33de0 RDI: ffffffff8be33da0
RBP: ffffc900031cfab0 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff8881a3c13000
R13: 0000000000000001 R14: ffff88801fbb9cc0 R15: 1ffff11026cc7551
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 _raw_spin_unlock+0x3f/0x50
 futex_wake+0x493/0x560
 do_futex+0x395/0x420
 __se_sys_futex+0x36f/0x400
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29e778eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f29e85cd0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f29e79d5fa8 RCX: 00007f29e778eba9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f29e79d5fac
RBP: 00007f29e79d5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f29e79d6038 R14: 00007ffff23dec10 R15: 00007ffff23decf8
 </TASK>
