INFO: task kworker/u8:3:5871 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:22760 pid:5871  tgid:5871  ppid:2      task_flags:0x4208060 flags:0x00004000
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+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.1.580:8003 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.580       state:D stack:22760 pid:8003  tgid:8002  ppid:5839   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: 0033:0x7f7bc038ebe9
RSP: 002b:00007f7bc113c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7bc05b5fa0 RCX: 00007f7bc038ebe9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007f7bc0411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7bc05b6038 R14: 00007f7bc05b5fa0 R15: 00007ffc22bc4a18
 </TASK>
INFO: lockdep is turned off.
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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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: 14874 Comm: syz.8.2392 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:__sanitizer_cov_trace_switch+0x82/0x130
Code: 00 00 b9 01 00 00 00 48 85 c0 0f 84 b4 00 00 00 41 57 41 56 41 54 53 48 8b 54 24 20 65 4c 8b 04 25 08 80 a0 92 45 31 c9 eb 08 <49> ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d e9 ce e0 10 41
RSP: 0018:ffffc9000895e800 EFLAGS: 00000093
RAX: 0000000000000020 RBX: 0000000000000004 RCX: 0000000000000005
RDX: ffffffff81c18685 RSI: ffffffff8e18ed80 RDI: 0000000000000004
RBP: 00000034890b38c5 R08: ffff888107338000 R09: 0000000000000013
R10: 0000000000000013 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8881006e7010 R14: ffff8881006e76b4 R15: 0000000000061aa4
FS:  0000000000000000(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ea24220 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rb_event_length+0x45/0x400
 rb_read_data_buffer+0x438/0x580
 check_buffer+0x28a/0x750
 __rb_reserve_next+0x592/0xdb0
 ring_buffer_lock_reserve+0xbb5/0x1010
 trace_event_buffer_lock_reserve+0x1d0/0x6f0
 trace_event_buffer_reserve+0x248/0x340
 trace_event_raw_event_bpf_trace_printk+0x100/0x260
 trace_bpf_trace_printk+0x170/0x1d0
 bpf_trace_printk+0x11e/0x190
 bpf_prog_9e1c00255e17e72e+0x39/0x3f
 bpf_trace_run1+0x27f/0x4b0
 __bpf_trace_rcu_utilization+0xa1/0xf0
 __traceiter_rcu_utilization+0x7a/0xb0
 trace_rcu_utilization+0x1ad/0x1d0
 rcu_note_context_switch+0xc9/0x1140
 __schedule+0x35d/0x4cc0
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 flush_tlb_mm_range+0xfa4/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 free_ldt_pgtables+0x17b/0x320
 exit_mmap+0x17c/0xb50
 __mmput+0x118/0x420
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb535b8ebe9
Code: Unable to access opcode bytes at 0x7fb535b8ebbf.
RSP: 002b:00007fb5369da0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb535db6098 RCX: 00007fb535b8ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb535db6098
RBP: 00007fb535db6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb535db6128 R14: 00007ffc799c45b0 R15: 00007ffc799c4698
 </TASK>
