INFO: task syz.3.6740:30381 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.6740      state:D stack:22808 pid:30381 tgid:30380 ppid:29737  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: 0033:0x7f5a37d8efc9
RSP: 002b:00007f5a38cd0038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5a37fe5fa0 RCX: 00007f5a37d8efc9
RDX: 0000000000008044 RSI: 0000200000000200 RDI: 000000000000000c
RBP: 00007f5a37e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a37fe6038 R14: 00007f5a37fe5fa0 R15: 00007ffd6cadf808
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000117ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
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/5637:
 #0: ffff88817646e0a0 (&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
1 lock held by sshd/5735:
3 locks held by kworker/0:4/5855:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90005427ba0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by udevd/22482:
 #0: ffff88810a353358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by kworker/0:0/29798:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000ab2fba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888115306240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
2 locks held by syz.3.6740/30381:
 #0: ffffffff99b608b8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.0.6747/30428:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.6846/30841:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.7299/32450:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.7299/32451:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.7562/944:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.7582/1055:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.7720/1578:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.7746/1664:
 #0: ffffffff8f2be270 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffff888114708700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
5 locks held by syz-executor/1943:
 #0: ffff88818f008dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff88818f0080b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f434c68 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
 #3: ffff888036928b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
 #4: ffffffff8df42d78 (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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 1938 Comm: syz-executor 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:kasan_check_range+0x4/0x2c0
Code: ff eb ec 90 0f 0b 90 b8 ea ff ff ff eb e1 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 <55> 41 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ba 01 00 00 4c
RSP: 0018:ffffc900081ef8b0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffea0006297c40 RCX: ffffffff82177830
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea0006297c70
RBP: ffffea0006297c48 R08: ffffea0006297c47 R09: 1ffffd4000c52f88
R10: dffffc0000000000 R11: fffff94000c52f89 R12: ffffea0006297c70
R13: 0000000000000000 R14: 1ffffd4000c52f8e R15: 0000000000000000
FS:  0000555566bb8500(0000) GS:ffff88818eb40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f3611e000 CR3: 000000000dd38000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __free_frozen_pages+0xa80/0xd30
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1285/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 exit_to_user_mode_loop+0x72/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc0ad7850d3
Code: Unable to access opcode bytes at 0x7fc0ad7850a9.
RSP: 002b:00007ffe6e08a0f8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000000797 RCX: 00007fc0ad7850d3
RDX: 0000000040000000 RSI: 00007ffe6e08a10c RDI: 00000000ffffffff
RBP: 00007ffe6e08a10c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
