INFO: task syz.1.2676:14749 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2676      state:D stack:24296 pid:14749 tgid:14748 ppid:5851   task_flags:0x400140 flags:0x00004004
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/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b5a98ebe9
RSP: 002b:00007f1b5b748038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1b5abc5fa0 RCX: 00007f1b5a98ebe9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007f1b5aa11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b5abc6038 R14: 00007f1b5abc5fa0 R15: 00007fff1dea3848
 </TASK>
INFO: task syz.2.2682:14765 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2682      state:D stack:25800 pid:14765 tgid:14764 ppid:5842   task_flags:0x400140 flags:0x00004006
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+0x2d3/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f619d58ebe9
RSP: 002b:00007f619e3d0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f619d7c5fa0 RCX: 00007f619d58ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f619d611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f619d7c6038 R14: 00007f619d7c5fa0 R15: 00007ffdbefcd7d8
 </TASK>
INFO: task syz.0.2684:14781 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2684      state:D stack:25224 pid:14781 tgid:14777 ppid:5846   task_flags:0x400140 flags:0x00004006
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+0x2d3/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98c2b8ebe9
RSP: 002b:00007f98c3a6d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f98c2dc6180 RCX: 00007f98c2b8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f98c2c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98c2dc6218 R14: 00007f98c2dc6180 R15: 00007ffd096a6dc8
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000f7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u12:0/56:
 #0: ffff8880204bb148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900007efbc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5672:
 #0: ffff8880262220a0 (&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
1 lock held by sshd/5828:
3 locks held by kworker/0:6/5904:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900039bfbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
2 locks held by syz.1.2676/14749:
 #0: ffffffff99e6e898 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.2.2682/14765:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.2684/14781:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.3065/16074:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.4117/19312:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.4117/19313:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.4290/19863:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.4399/20240:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.4534/20746:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.4664/21148:
 #0: ffffffff8f52be90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888113c1c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
5 locks held by syz.1.4732/21366:
 #0: ffff888130c74dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff888130c740b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f69dec8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
 #3: ffff88803431a338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
 #4: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
3 locks held by syz.2.4735/21378:
 #0: ffff88806b2dcdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff88806b2dc0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f69dec8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230

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

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: 20726 Comm: kworker/u10:6 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: events_unbound nsim_dev_trap_report_work
RIP: 0010:validate_chain+0x18f5/0x2140
Code: 8d 48 c7 c6 9e cd a9 8d e8 18 90 e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 c0 30 49 39 c7 0f 84 5a 01 00 00 49 8b 5f 10 <41> 8b 44 24 f8 25 ff 1f 00 00 48 0f a3 05 59 c9 0a 12 0f 82 5a ff
RSP: 0018:ffffc900000063d8 EFLAGS: 00000006
RAX: ffffffff9349a1b8 RBX: ffffffff934a9160 RCX: 0000000000000003
RDX: 0000000000030000 RSI: 0000000000000000 RDI: ffff8881287ab980
RBP: 0000000000000000 R08: ffffc900000063a0 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819dcc10 R12: ffff8881287ac628
R13: ffff8881287ac470 R14: ffff8881287ac628 R15: ffffffff9632c0a8
FS:  0000000000000000(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2f67e86f98 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 stack_depot_save_flags+0x25d/0x860
 kasan_save_track+0x4f/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_track_caller_noprof+0x271/0x4e0
 kmalloc_reserve+0x136/0x290
 pskb_expand_head+0x18e/0x1150
 gre_tap_xmit+0x4d5/0x7a0
 dev_hard_start_xmit+0x2d7/0x830
 sch_direct_xmit+0x241/0x4b0
 __dev_queue_xmit+0x1857/0x3b50
 bond_dev_queue_xmit+0x10b/0x1e0
 bond_start_xmit+0x779/0x1a10
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 ip6_finish_output2+0xf70/0x1480
 ip6_output+0x340/0x550
 ndisc_send_skb+0xbce/0x1510
 addrconf_rs_timer+0x369/0x670
 call_timer_fn+0x17e/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:lock_acquire+0x58/0x360
Code: 8b 05 7c 65 03 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 7f 65 03 11 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 68 38 06 0e <73> 16 e8 61 02 09 00 84 c0 75 0d f6 05 80 1e f0 0d 01 0f 84 d7 01
RSP: 0018:ffffc90002edf438 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e139ee0
RBP: ffffffff8172c195 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90002edf5f8 R11: ffffffff81ac3820 R12: 0000000000000002
R13: ffffffff8e139ee0 R14: 0000000000000000 R15: 0000000000000000
 unwind_next_frame+0xc2/0x2390
 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
 nsim_dev_trap_report_work+0x7cf/0xb80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
