INFO: task kworker/u8:3:5848 blocked for more than 143 seconds.
      Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:24304 pid:5848  tgid:5848  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __schedule+0x1737/0x4d30
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e3/0x1340
 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.2.5756:19182 blocked for more than 143 seconds.
      Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.5756      state:D stack:23512 pid:19182 tgid:19180 ppid:5817   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1737/0x4d30
 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: 0033:0x7f2efa98eb69
RSP: 002b:00007f2efb833038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2efabb5fa0 RCX: 00007f2efa98eb69
RDX: 0000000000008044 RSI: 0000200000000200 RDI: 000000000000000a
RBP: 00007f2efaa11df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2efabb5fa0 R15: 00007fffc15a1c68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5647:
 #0: ffff8880271770a0 (&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/5807:
1 lock held by syz-executor/5826:
 #0: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
4 locks held by kworker/u8:3/5848:
 #0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003e5fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f4fc190 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff88812d6b46d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.5756/19182:
 #0: ffffffff99e12978 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff88812d6b46d0 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
1 lock held by syz-executor/19856:
 #0: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f-dirty #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: 19843 Comm: syz-executor Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f-dirty #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:lock_acquire+0xdb/0x360
Code: 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa <48> c7 c7 b0 cb 98 8d e8 b9 72 d2 09 65 ff 05 62 cf fc 10 45 31 c9
RSP: 0018:ffffc90007d77498 EFLAGS: 00000046
RAX: ffff888126b7b980 RBX: 0000000000000000 RCX: e9043469d4712d00
RDX: 0000000000000000 RSI: ffffffff8172cd22 RDI: 1ffffffff1c2789c
RBP: ffffffff8172cd05 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90007d77658 R11: ffffffff81ac3450 R12: 0000000000000002
R13: ffffffff8e13c4e0 R14: 0000000000000000 R15: 0000000000000246
FS:  0000555587124500(0000) GS:ffff8880b8680000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f672aae7d60 CR3: 000000001183e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __reset_page_owner+0x71/0x1f0
 __free_frozen_pages+0xc71/0xe70
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x22e0
 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: 0033:0x7f30c0f84d93
Code: Unable to access opcode bytes at 0x7f30c0f84d69.
RSP: 002b:00007ffc7cd943e8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000004d90 RCX: 00007f30c0f84d93
RDX: 0000000040000000 RSI: 00007ffc7cd943fc RDI: 00000000ffffffff
RBP: 00007ffc7cd943fc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
