INFO: task kworker/u8:4:6827 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00135-gcf074eca0065 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:23816 pid:6827  tgid:6827  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __schedule+0x16f5/0x4d00
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x724/0xe80
 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.2.3472:19272 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00135-gcf074eca0065 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3472      state:D stack:23736 pid:19272 tgid:19267 ppid:5835   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x16f5/0x4d00
 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+0x75c/0x8e0
 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: 0033:0x7f942f58e9a9
RSP: 002b:00007f9430485038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f942f7b6080 RCX: 00007f942f58e9a9
RDX: 0000000000004090 RSI: 0000200000000400 RDI: 000000000000000e
RBP: 00007f942f610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f942f7b6080 R15: 00007ffd9cd261f8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5654:
 #0: ffff88810a99d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000268f2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:4/6827:
 #0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900031dfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.3472/19272:
 #0: ffffffff99e6e718 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.1.3606/19768:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.3620/19854:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.3890/20941:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.3973/21276:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.4098/21791:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.4104/21819:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.4136/21996:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.4220/22296:
 #0: ffffffff8f50f050 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88803a4806d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00135-gcf074eca0065 #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+0xfee/0x1030
 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: 23498 Comm: syz.2.4527 Not tainted 6.16.0-rc6-syzkaller-00135-gcf074eca0065 #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:validate_chain+0xa4/0x2140
Code: c6 1b 9b a7 8d e8 dc 93 e5 ff 90 0f 0b 90 90 90 48 bb eb 83 b5 80 46 86 c8 61 49 0f af df 48 c1 eb 2d 48 8b 04 dd 20 83 63 93 <48> 85 c0 0f 94 c1 48 83 c0 f8 0f 94 c2 08 ca 0f 84 24 01 00 00 e8
RSP: 0018:ffffc90009896cb8 EFLAGS: 00000007
RAX: ffffffff93a7fcf8 RBX: 000000000003933a RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff888079eca828 RDI: ffff888079ec9cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff84c687ea
R10: ffffc90009896fb0 R11: fffff52001312df8 R12: 0000000000000000
R13: ffff888079eca7b0 R14: ffff888079eca828 R15: 627ea00daf3c6465
FS:  000055558db5c500(0000) GS:ffff8880b8623000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbcd982ab8 CR3: 00000000720e0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 debug_object_deactivate+0x9a/0x250
 debug_deactivate+0x1d/0x200
 hrtimer_try_to_cancel+0x2ff/0x420
 task_contending+0x3e7/0x6e0
 enqueue_dl_entity+0x8c1/0x1d40
 dl_server_start+0xe5/0x280
 enqueue_task_fair+0xea1/0x1470
 enqueue_task+0x75/0x420
 activate_task+0x58/0xc0
 attach_task+0xf0/0x190
 sched_balance_rq+0x416b/0x57a0
 sched_balance_newidle+0x693/0xfb0
 pick_next_task_fair+0x40/0xba0
 __pick_next_task+0xe4/0x450
 __schedule+0x6fe/0x4d00
 schedule+0x165/0x360
 do_nanosleep+0x1c7/0x600
 hrtimer_nanosleep+0x169/0x360
 __se_sys_clock_nanosleep+0x2f1/0x380
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1be09c1265
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007fff30c06150 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007f1be0bb5fa0 RCX: 00007f1be09c1265
RDX: 00007fff30c06190 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1be0bb7ba0 R08: 0000000000000000 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000081368
R13: 00007f1be0bb6080 R14: ffffffffffffffff R15: 00007fff30c062d0
 </TASK>
