INFO: task kworker/u8:5:5908 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:23352 pid:5908  tgid:5908  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 rdma_dev_change_netns+0x39/0x300
 rdma_dev_exit_net+0x203/0x340
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4d8/0x7a0
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.1.9839:13125 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.9839      state:D stack:22440 pid:13125 tgid:13124 ppid:5839   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7facf1b8f7c9
RSP: 002b:00007facefdf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007facf1de5fa0 RCX: 00007facf1b8f7c9
RDX: 0000000000000000 RSI: 0000200000000400 RDI: 000000000000000c
RBP: 00007facf1bf297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007facf1de6038 R14: 00007facf1de5fa0 R15: 00007ffc10131bf8
 </TASK>
INFO: task syz.2.9930:13467 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.9930      state:D stack:25800 pid:13467 tgid:13465 ppid:9448   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 rdma_dev_change_netns+0x39/0x300
 rdma_dev_exit_net+0x203/0x340
 ops_undo_list+0x49a/0x990
 setup_net+0x2e8/0x330
 copy_net_ns+0x3e3/0x570
 create_new_namespaces+0x3e7/0x6a0
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0de1f8f7c9
RSP: 002b:00007f0de2e05038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f0de21e6090 RCX: 00007f0de1f8f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f0de1ff297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0de21e6128 R14: 00007f0de21e6090 R15: 00007ffca7ee3f38
 </TASK>
INFO: task syz.0.9931:13473 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9931      state:D stack:25592 pid:13473 tgid:13470 ppid:5844   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 rdma_dev_change_netns+0x39/0x300
 rdma_dev_exit_net+0x203/0x340
 ops_undo_list+0x49a/0x990
 setup_net+0x2e8/0x330
 copy_net_ns+0x3e3/0x570
 create_new_namespaces+0x3e7/0x6a0
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa39678f7c9
RSP: 002b:00007fa3949f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fa3969e6180 RCX: 00007fa39678f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068040200
RBP: 00007fa3967f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3969e6218 R14: 00007fa3969e6180 R15: 00007ffdef7f9558
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8df41cc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5660:
 #0: ffff8881161470a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:5/5908:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90004537b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0
 #3: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
3 locks held by kworker/0:0/11879:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90007337b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffff88801190d240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
2 locks held by syz.1.9839/13125:
 #0: ffffffff99befc98 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.2.9930/13467:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.9931/13473:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
3 locks held by kworker/u8:6/13564:
 #0: ffff888113431148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc9000928fb80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f2f55c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
3 locks held by kworker/u8:7/13565:
 #0: ffff8881161f9948 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90008f0fb80 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f2f55c8 (rtnl_mutex){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work+0x29/0xa10
2 locks held by syz.3.9981/13732:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.10034/13954:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.10034/13955:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.10117/14286:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.10238/14777:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.10316/15086:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.10584/16194:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.10645/16429:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.10742/16813:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.10745/16832:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.10746/16853:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.10771/17016:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.10771/17017:
 #0: ffffffff8f2e8510 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570
 #1: ffff8881ba22c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz-executor/17673:
 #0: ffffffff8f809780 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f2f55c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90
4 locks held by syz.5.10956/17715:
 #0: ffff888049c48ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff888049c480c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0xff0
 #2: ffffffff8f467308 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
 #3: ffff88803c051338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
2 locks held by syz.6.10957/17719:
 #0: ffffffff8f2f55c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90
 #1: ffffffff8df477f8 (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+0xf3c/0xf80
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 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: 0 Comm: swapper/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
RIP: 0010:pv_native_safe_halt+0x13/0x20
Code: 53 ec 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 53 0d 1f 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 00000286
RAX: 0d29c022571dfd00 RBX: ffffffff8197438a RCX: 0d29c022571dfd00
RDX: 0000000000000001 RSI: ffffffff8d76bd9d RDI: ffffffff8bbfc660
RBP: ffffffff8dc07ea8 R08: ffff88812123359b R09: 1ffff110242466b3
R10: dffffc0000000000 R11: ffffed10242466b4 R12: ffffffff8f805a70
R13: 1ffffffff1b92a50 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88818eab1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5dc71ea440 CR3: 0000000026bb8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 default_idle+0x13/0x20
 default_idle_call+0x73/0xb0
 do_idle+0x1ea/0x520
 cpu_startup_entry+0x44/0x60
 rest_init+0x2de/0x300
 start_kernel+0x3ae/0x410
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x143/0x1c0
 common_startup_64+0x13e/0x147
 </TASK>
IPVS: rr: UDP 224.0.0.2:0 - no destination available
net_ratelimit: 5 callbacks suppressed
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
net_ratelimit: 5 callbacks suppressed
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
IPVS: rr: UDP 224.0.0.2:0 - no destination available
