INFO: task syz.1.998:8240 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.998       state:D stack:23856 pid:8240  tgid:8238  ppid:5842   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: 0033:0x7fe5d0b8ec29
RSP: 002b:00007fe5cedf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe5d0dd6090 RCX: 00007fe5d0b8ec29
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000009
RBP: 00007fe5d0c11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe5d0dd6128 R14: 00007fe5d0dd6090 R15: 00007fffc61cfc88
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
1 lock held by khungtaskd/34:
 #0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5676:
 #0: ffff8880299d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900028fe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:2/5856:
 #0: ffff88801baff148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003127ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f730fd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffff88812081c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.998/8240:
 #0: ffffffff9a080fd8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff88812081c700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.3.2926/12711:
 #0: ffffffff8f741468 (bpf_dispatcher_xdp.mutex){+.+.}-{4:4}, at: bpf_dispatcher_change_prog+0x9c/0xc90
 #1: ffffffff8e342df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.6.2930/12721:
 #0: ffffffff8e342df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

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: 12709 Comm: syz.0.2925 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:unwind_next_frame+0x77/0x2390
Code: 4c 89 e8 48 c1 e8 03 48 89 44 24 58 80 3c 28 00 74 08 4c 89 ef e8 d9 6a b1 00 4d 8b 7e 38 4d 89 f4 49 c1 ec 03 41 0f b6 04 2c <84> c0 0f 85 de 1b 00 00 41 8b 06 85 c0 0f 84 32 02 00 00 89 84 24
RSP: 0018:ffffc90006997538 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffffff8b7de31d RCX: b9e7464417164300
RDX: dffffc0000000000 RSI: ffffffff8b7de31d RDI: ffffc90006997608
RBP: dffffc0000000000 R08: ffffc900069976d0 R09: 000000000000000a
R10: ffffc90006997658 R11: ffffffff81acd5a0 R12: 1ffff92000d32ec1
R13: ffffc90006997640 R14: ffffc90006997608 R15: ffffc90006997ee0
FS:  00007f13aee746c0(0000) GS:ffff8881a3a03000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe834a87e20 CR3: 000000000e138000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __reset_page_owner+0x71/0x1f0
 __free_frozen_pages+0xbc4/0xd30
 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: 0033:0x7f13adf8ec29
Code: Unable to access opcode bytes at 0x7f13adf8ebff.
RSP: 002b:00007f13aee74038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: fffffffffffffe00 RBX: 00007f13ae1d5fa0 RCX: 00007f13adf8ec29
RDX: 0000000000010000 RSI: 0000200000000300 RDI: 0000000000000003
RBP: 00007f13ae011e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f13ae1d6038 R14: 00007f13ae1d5fa0 R15: 00007ffe28c17b68
 </TASK>
