INFO: task kworker/u8:3:22355 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:23720 pid:22355 tgid:22355 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 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+0x4d8/0x820
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.2.11623:969 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.11623     state:D stack:22808 pid:969   tgid:968   ppid:5820   task_flags:0x400140 flags:0x00080002
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/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa4eeb8efc9
RSP: 002b:00007fa4ef96a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa4eede5fa0 RCX: 00007fa4eeb8efc9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007fa4eec11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa4eede6038 R14: 00007fa4eede5fa0 R15: 00007ffc0f1a4398
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8df3d620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5638:
 #0: ffff88816dd510a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:3/22355:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000a6dfba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2c1870 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffff8881a7d48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
4 locks held by kworker/1:3/27875:
 #0: ffff888168071d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000855fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88816cfaf198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888037b0b198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
2 locks held by syz.2.11623/969:
 #0: ffffffff99b6e918 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff8881a7d48700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
4 locks held by udevd/1438:
 #0: ffff8880242df540 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20
 #1: ffff88811b213488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420
 #2: ffff8881962042d8 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420
 #3: ffff888037b0b198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0
2 locks held by dhcpcd/5449:
 #0: ffff888023a4a260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
 #1: ffffffff8df430b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 27875 Comm: kworker/1:3 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: usb_hub_wq hub_event
RIP: 0010:vprintk_emit+0x49d/0x590
Code: 0f 84 34 ff ff ff e8 92 f0 1f 00 fb eb 44 e8 8a f0 1f 00 e8 55 77 a7 09 4d 85 f6 74 94 e8 7b f0 1f 00 fb 48 c7 c7 00 16 f3 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 0b 39
RSP: 0000:ffffc9000855e580 EFLAGS: 00000283
RAX: ffffffff81a02ac5 RBX: ffffffff81a0291e RCX: 0000000000100000
RDX: ffffc90027a35000 RSI: 000000000006572e RDI: ffffffff8df31600
RBP: ffffc9000855e690 R08: ffffffff8f7d1677 R09: 1ffffffff1efa2ce
R10: dffffc0000000000 R11: fffffbfff1efa2cf R12: 0000000000000000
R13: 000000000000002a R14: 0000000000000200 R15: 1ffff920010abcb4
FS:  0000000000000000(0000) GS:ffff8882a9f32000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31616ff8 CR3: 0000000169cfa000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 dev_vprintk_emit+0x337/0x3f0
 dev_printk_emit+0xe0/0x130
 _dev_info+0x10a/0x160
 cdc_ncm_bind_common+0x1e80/0x3040
 huawei_cdc_ncm_bind+0x2f/0x170
 usbnet_probe+0xa96/0x2870
 usb_probe_interface+0x668/0xc30
 really_probe+0x26d/0x9e0
 __driver_probe_device+0x18c/0x2f0
 driver_probe_device+0x4f/0x430
 __device_attach_driver+0x2ce/0x530
 bus_for_each_drv+0x251/0x2e0
 __device_attach+0x2b8/0x400
 bus_probe_device+0x185/0x260
 device_add+0x7b6/0xb50
 usb_set_configuration+0x1a87/0x20e0
 usb_generic_driver_probe+0x8d/0x150
 usb_probe_device+0x1c4/0x390
 really_probe+0x26d/0x9e0
 __driver_probe_device+0x18c/0x2f0
 driver_probe_device+0x4f/0x430
 __device_attach_driver+0x2ce/0x530
 bus_for_each_drv+0x251/0x2e0
 __device_attach+0x2b8/0x400
 bus_probe_device+0x185/0x260
 device_add+0x7b6/0xb50
 usb_new_device+0xa39/0x16f0
 hub_event+0x2958/0x4a20
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
