INFO: task kworker/u8:3:5837 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:21400 pid:5837  tgid:5837  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.0.7527:3562 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.7527      state:D stack:23648 pid:3562  tgid:3560  ppid:5809   task_flags:0x400140 flags:0x00080003
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
 setup_net+0x2d6/0x320
 copy_net_ns+0x34e/0x4e0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f791a38f6c9
RSP: 002b:00007f791b24c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f791a5e6090 RCX: 00007f791a38f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f791a411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f791a5e6128 R14: 00007f791a5e6090 R15: 00007ffdfa7a3ef8
 </TASK>
INFO: task syz.2.7536:3597 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.7536      state:D stack:23968 pid:3597  tgid:3595  ppid:5819   task_flags:0x400140 flags:0x00080003
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: 0033:0x7f0a1858f6c9
RSP: 002b:00007f0a193c9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0a187e6090 RCX: 00007f0a1858f6c9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 000000000000000a
RBP: 00007f0a18611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a187e6128 R14: 00007f0a187e6090 R15: 00007ffe512eea68
 </TASK>
INFO: task syz.1.7556:3677 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.7556      state:D stack:26280 pid:3677  tgid:3676  ppid:5814   task_flags:0x400140 flags:0x00080003
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
 setup_net+0x2d6/0x320
 copy_net_ns+0x34e/0x4e0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a1598f6c9
RSP: 002b:00007f5a1674c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f5a15be5fa0 RCX: 00007f5a1598f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007f5a15a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a15be6038 R14: 00007f5a15be5fa0 R15: 00007ffdcd6e60c8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5640:
 #0: ffff888172a6c0a0 (&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/u8:3/5837:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90004ca7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by udevd/24871:
 #0: ffff8881094f2358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/24907:
 #0: ffff8881094f6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by kworker/u9:9/26721:
 #0: ffff888100089948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003eefba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2cb408 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by udevd/2953:
 #0: ffff88810947e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by syz.0.7527/3562:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.7536/3597:
 #0: ffffffff99b628b8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.1.7556/3677:
 #0: ffffffff8f2be470
 (
pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.7575/3790:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.7709/4340:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.7739/4479:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.7776/4615:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.7796/4727:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.7808/4775:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.7835/4916:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.7886/5144:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.7896/5179:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.7896/5180:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.7901/5220:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.7903/5253:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.7943/5441:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.7943/5442:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.7972/5565:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.7981/5636:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.8002/5774:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.8092/6217:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.8142/6421:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.8142/6422:
 #0: ffffffff8f2be470 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff8881163ac700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.8171/6523:
 #0: ffffffff8f2cb408 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+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: 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_iv_send_outstanding_bat_ogm_packet
RIP: 0010:batadv_iv_ogm_schedule+0x673/0xf00
Code: 74 13 49 81 c5 38 fe ff ff 74 0a e8 47 87 b0 f6 e9 ab fe ff ff e8 3d 87 b0 f6 e8 c8 8e 36 00 89 c3 31 ff 89 c6 e8 6d 8b b0 f6 <85> db 4c 8b a4 24 88 00 00 00 4c 8b ac 24 80 00 00 00 74 15 e8 84
RSP: 0018:ffffc90000117860 EFLAGS: 00000293
RAX: ffffffff8b0f9a13 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff8881026a5700 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001179b0 R08: 0000000000000000 R09: ffffffff8b0f97d0
R10: dffffc0000000000 R11: ffffed10315e5117 R12: ffff8881a9fb7b00
R13: fffffffffffffe38 R14: dffffc0000000000 R15: ffff88818b36c430
FS:  0000000000000000(0000) GS:ffff8882a9f3e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555564b655c8 CR3: 000000016f748000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
ip6_tunnel: ip6gre1 xmit: Local address not yet configured!
