INFO: task kworker/u8:4:5903 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:22824 pid:5903  tgid:5903  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+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.1.5648:27428 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.5648      state:D stack:24232 pid:27428 tgid:27427 ppid:5859   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: 0033:0x7fde2138eba9
RSP: 002b:00007fde221fe038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fde215d5fa0 RCX: 00007fde2138eba9
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007fde21411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde215d6038 R14: 00007fde215d5fa0 R15: 00007ffc908ce9c8
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
3 locks held by kworker/0:1/10:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000d7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kswapd1/91:
2 locks held by getty/5668:
 #0: ffff88810eee40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by sshd/5832:
2 locks held by kworker/u8:2/5869:
4 locks held by kworker/u8:4/5903:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000477fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.5648/27428:
 #0: ffffffff99e6f8f8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.2.5889/28310:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.6016/28736:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.6072/28968:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.6234/29619:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.6241/29650:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.6258/29705:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.6343/30085:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.6414/30340:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.6423/30399:
 #0: ffffffff8f52d370 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888032b48700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
3 locks held by kworker/u9:23/30473:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003657bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
4 locks held by syz.2.6503/30711:
 #0: ffff888012234dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff8880122340b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f69eb68 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
 #3: ffff88803b1f1338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
1 lock held by syz.3.6505/30718:
 #0: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: ip_mroute_setsockopt+0x107/0xf60
2 locks held by syz.1.6507/30725:
 #0: ffffffff8f53a208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x346/0x700
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 5832 Comm: sshd 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:rcu_is_watching+0x44/0xb0
Code: 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 1d be 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 ec c3 7c 00 <48> c7 c3 98 ff a1 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38
RSP: 0000:ffffc900033bf4c8 EFLAGS: 00000246
RAX: 1ffffffff1b7c3a3 RBX: 0000000000000001 RCX: 5479a44e6d84a700
RDX: 0000000000000000 RSI: ffffffff8be33be0 RDI: ffffffff8be33ba0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8215df2d
R10: ffffc900033bf600 R11: fffff52000677ec5 R12: ffffc900033bf618
R13: ffffffff8215df2d R14: ffffffff8dbe1d18 R15: dffffc0000000000
FS:  00007ff4b90ad800(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff4b8ecab40 CR3: 0000000029120000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_release+0x4b/0x3e0
 prepare_alloc_pages+0x153/0x610
 __alloc_frozen_pages_noprof+0x123/0x370
 alloc_pages_mpol+0x232/0x4a0
 alloc_pages_noprof+0xa9/0x190
 folio_alloc_noprof+0x1e/0x30
 filemap_alloc_folio_noprof+0xdf/0x470
 page_cache_ra_unbounded+0x2b9/0x7b0
 do_sync_mmap_readahead+0x25e/0x7a0
 filemap_fault+0x62c/0x1200
 __do_fault+0x138/0x390
 __handle_mm_fault+0x3611/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7ff4b8ecab40
Code: Unable to access opcode bytes at 0x7ff4b8ecab16.
RSP: 002b:00007fff6dae3a58 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000055a7df61b5c0 RCX: 000055a7df61b5c0
RDX: 0000000000000040 RSI: 000055a7df61b5f0 RDI: 000055a7df61b5f0
RBP: 0000000000000000 R08: 000055a7df61b5e0 R09: 000055a7df61b5f0
R10: 0000000000000000 R11: 0000000000000000 R12: 00007fff6dae3af8
R13: 0000000000000020 R14: 0000000000000000 R15: 00007fff6dae3af8
 </TASK>
