INFO: task kworker/u9:6:1091 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:6    state:D stack:20712 pid:1091  tgid:1091  ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: ib-unreg-wq ib_unregister_work
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_work+0x19/0x30
 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.3.2839:17635 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2839      state:D stack:26408 pid:17635 tgid:17634 ppid:17382  task_flags:0x400140 flags:0x00004006
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
 setup_net+0x2d3/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f075a38ec29
RSP: 002b:00007f075b229038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f075a5d5fa0 RCX: 00007f075a38ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f075a411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f075a5d6038 R14: 00007f075a5d5fa0 R15: 00007ffc26fab568
 </TASK>

Showing all locks held in the system:
3 locks held by init/1:
4 locks held by kworker/u8:1/13:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000107bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x721/0xea0
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:6/1091:
 #0: ffff888105511948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006d57bc0 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
1 lock held by jbd2/sda1-8/5256:
3 locks held by dhcpcd/5589:
3 locks held by sshd/5668:
2 locks held by getty/5672:
 #0: ffff8881088f90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900028c82f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by kworker/0:7/11931:
2 locks held by syz.3.2839/17635:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.2924/17950:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.2968/18147:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.2968/18148:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.3050/18480:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
3 locks held by kworker/u8:6/19021:
 #0: ffff88810ddaf948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002d6fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
2 locks held by syz.7.3198/19138:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.3215/19199:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.3269/19417:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.3320/19665:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.3328/19700:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock
){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
4 locks held by kworker/u11:3/19914:
 #0: ffff888122a0a948 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900081b7bc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8881089d0dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
 #3: ffff8881089d00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30
2 locks held by syz.0.3387/20003:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.3390/20016:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.3401/20054:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
5 locks held by kworker/u11:4/20057:
4 locks held by syz-executor/20058:
3 locks held by syz-executor/20059:
2 locks held by syz-executor/20060:
4 locks held by syz-executor/20076:
2 locks held by syz.7.3408/20156:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.3420/20204:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88802f92c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by syz.5.3423/20213:
2 locks held by syz.5.3423/20214:
2 locks held by syz.5.3423/20215:
2 locks held by syz.5.3423/20216:
 #0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0

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

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: 101 PID: 5589 Comm: dhcpcd 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:check_preemption_disabled+0x40/0x120
Code: 08 65 8b 05 c6 ae 25 07 65 8b 0d bb ae 25 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b ae 25 07 48 3b 4c 24 08 0f 85 cc 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d e9 81 ca 02 00 cc 48 c7 04 24 00 00
RSP: 0000:ffffc90002cee450 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000087 RCX: 225a661f5fd6e100
RDX: 0000000000000005 RSI: ffffffff8dba98f7 RDI: ffffffff8be33f00
RBP: ffff88810626e1f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200059dc90 R12: 0000000000000005
R13: 0000000000000005 R14: ffffffff8e12e2d8 R15: ffff88810626d640
FS:  00007f97107e4740(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb0c90bcae0 CR3: 0000000108368000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_release+0x27a/0x3e0
 _raw_spin_unlock+0x16/0x50
 console_flush_all+0x6ac/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 dump_unreclaimable_slab+0x112/0x150
 dump_header+0x39e/0x480
 oom_kill_process+0x387/0x920
 out_of_memory+0xfe1/0x12a0
 __alloc_pages_may_oom+0x1f2/0x330
 __alloc_pages_slowpath+0x706/0xce0
 __alloc_frozen_pages_noprof+0x319/0x370
 alloc_pages_mpol+0x232/0x4a0
 folio_alloc_mpol_noprof+0x39/0x70
 __read_swap_cache_async+0x166/0x510
 swap_cluster_readahead+0x4cf/0x5f0
 swapin_readahead+0x17d/0xb50
 do_swap_page+0x525/0x5ac0
 __handle_mm_fault+0xe55/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0x764/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0010:do_sys_poll+0xe52/0x1070
Code: 8b 74 24 18 4c 8d 76 12 45 31 ff 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 2b 42 0f b7 44 fe 12 <66> 89 02 49 89 d4 44 39 fb 74 3b e8 3e b3 85 ff 4c 89 e2 48 83 c2
RSP: 0000:ffffc90002cef840 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: dffffc0000000000
RDX: 000055b0ecb64b66 RSI: ffffc90002cefc50 RDI: 0000000000000000
RBP: ffffc90002cefdf0 R08: ffff88802886e567 R09: 1ffff1100510dcac
R10: dffffc0000000000 R11: ffffed100510dcad R12: 000055b0ecb64b80
R13: 0000000000000000 R14: ffffc90002cefc62 R15: 0000000000000000
 __se_sys_ppoll+0x1ff/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f97108b1ad5
Code: Unable to access opcode bytes at 0x7f97108b1aab.
RSP: 002b:00007ffdb159ef10 EFLAGS: 00000246 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 000055b0ecb57e10 RCX: 00007f97108b1ad5
RDX: 00007ffdb159ef30 RSI: 0000000000000004 RDI: 000055b0ecb64b60
RBP: 00007ffdb159f260 R08: 0000000000000008 R09: 7fffffffffffffff
R10: 00007ffdb159f260 R11: 0000000000000246 R12: 00007ffdb159ef58
R13: 000055b0e978e610 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
