INFO: task kworker/u9:4:3909 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:4    state:D stack:24232 pid:3909  tgid:3909  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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.0.196:6615 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.196       state:D stack:21432 pid:6615  tgid:6614  ppid:5839   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1360
 rdma_dev_change_netns+0x39/0x300
 rdma_dev_exit_net+0x203/0x340
 ops_undo_list+0x49a/0x990
 setup_net+0x2d3/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 copy_namespaces+0x438/0x4b0
 copy_process+0x1733/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f86c4d8ebe9
RSP: 002b:00007f86c5b5ffe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f86c4fb5fa0 RCX: 00007f86c4d8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ef220000
RBP: 00007f86c4e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f86c4fb6038 R14: 00007f86c4fb5fa0 R15: 00007fff3254ab28
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u10:0/27:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000060fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f537dc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ea0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:4/3909:
 #0: ffff88801bb2e148 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000465fbc0 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88811d1c4700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by getty/5671:
 #0: ffff88810faa70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:4/5911:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003d7fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52af70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8e13f800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
2 locks held by syz.0.196/6615:
 #0: ffffffff8f52af70 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88811d1c4700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.390/7596:
 #0: ffffffff8f52af70 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88811d1c4700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.438/7761:
 #0: ffffffff8f52af70 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88811d1c4700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.484/7932:
1 lock held by syz.8.492/7967:
 #0: ffffffff8e13f800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
1 lock held by syz-executor/7971:
 #0: ffffffff8e13f938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
3 locks held by syz-executor/7976:
 #0: ffffffff8eca8200 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f537dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #2: ffffffff8e13f938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz-executor/7982:
 #0: ffffffff8f537dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70

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

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: 7932 Comm: syz.9.484 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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 4b e3 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000007b00 EFLAGS: 00000206
RAX: 6679d96323ee3200 RBX: 0000000000000000 RCX: 6679d96323ee3200
RDX: 0000000000000000 RSI: ffffffff8dba5cac RDI: ffffffff8be33300
RBP: ffffffff81ad642e R08: 0000000000000000 R09: ffffffff81ad642e
R10: ffffc90000007be8 R11: fffff52000000f7f R12: 0000000000000000
R13: ffffc90000007be0 R14: 0000000000000001 R15: 0000000000000246
FS:  00007f1c1e9316c0(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564fe37af428 CR3: 00000000334a8000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0xdb/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 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:raw_spin_rq_unlock_irq+0x13/0x90
Code: cc e8 21 08 e7 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 66 90 e8 c4 9e e9 09 e8 ef 26 35 00 fb 5b <41> 5e 41 5f c3 cc cc cc cc cc f3 0f 1e fa 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc900029ff808 EFLAGS: 00000286
RAX: 6679d96323ee3200 RBX: ffff88804b039f80 RCX: 6679d96323ee3200
RDX: 0000000000000000 RSI: ffffffff8d9b6a0a RDI: ffffffff8be33300
RBP: ffffc900029ffa30 R08: ffffffff8fa38037 R09: 1ffffffff1f47006
R10: dffffc0000000000 R11: fffffbfff1f47007 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880347b8000 R15: 1ffff11009607551
 __schedule+0x19e0/0x4cc0
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:task_mm_cid_work+0x4/0x760
Code: ff ff 4c 89 ff e8 4c 5a 91 00 e9 3c ff ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00
RSP: 0018:ffffc900029ffbb8 EFLAGS: 00000246
RAX: 1ffff110068f72b4 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8d9b6a0a RDI: ffff8880347b9598
RBP: ffffc900029ffc80 R08: ffffffff8fa38037 R09: 1ffffffff1f47006
R10: dffffc0000000000 R11: ffffffff8191c590 R12: dffffc0000000000
R13: ffff8880347b9598 R14: ffff8880347b8a10 R15: ffff8880347b8978
 task_work_run+0x1d4/0x260
 get_signal+0x11ed/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c1db8ebe9
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:00007f1c1e931038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: 0000000000000008 RBX: 00007f1c1ddb6090 RCX: 00007f1c1db8ebe9
RDX: 0000000000000048 RSI: 0000200000000200 RDI: 0000000000000000
RBP: 00007f1c1dc11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1c1ddb6128 R14: 00007f1c1ddb6090 R15: 00007ffd6787be38
 </TASK>
