INFO: task kworker/u8:3:5840 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:21848 pid:5840  tgid:5840  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.2.435:7521 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.435       state:D stack:24848 pid:7521  tgid:7520  ppid:5812   task_flags:0x400140 flags:0x00004006
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
 setup_net+0x3e2/0x4b0
 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: 0033:0x7f819298e929
RSP: 002b:00007f8193867038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f8192bb5fa0 RCX: 00007f819298e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f8192a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8192bb5fa0 R15: 00007ffea2ff9068
 </TASK>
INFO: task syz.2.435:7522 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.435       state:D stack:22808 pid:7522  tgid:7520  ppid:5812   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+0x75b/0x8d0
 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: 0033:0x7f819298e929
RSP: 002b:00007f8193846038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8192bb6080 RCX: 00007f819298e929
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000005
RBP: 00007f8192a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8192bb6080 R15: 00007ffea2ff9068
 </TASK>
INFO: task syz.0.501:7800 blocked for more than 145 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.501       state:D stack:25912 pid:7800  tgid:7798  ppid:5817   task_flags:0x400140 flags:0x00004006
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
 setup_net+0x3e2/0x4b0
 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: 0033:0x7feb8818e929
RSP: 002b:00007feb88f26038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007feb883b6080 RCX: 00007feb8818e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068040200
RBP: 00007feb88210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feb883b6080 R15: 00007ffdfacd5c78
 </TASK>
INFO: task syz.0.501:7807 blocked for more than 146 seconds.
      Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.501       state:D stack:26392 pid:7807  tgid:7798  ppid:5817   task_flags:0x400140 flags:0x00004006
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
 setup_net+0x3e2/0x4b0
 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: 0033:0x7feb8818e929
RSP: 002b:00007feb85ff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007feb883b6160 RCX: 00007feb8818e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068040200
RBP: 00007feb88210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007feb883b6160 R15: 00007ffdfacd5c78
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:2/932:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000698fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f510488 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by klogd/5249:
3 locks held by udevd/5260:
2 locks held by dhcpcd/5556:
2 locks held by getty/5636:
 #0: ffff88810ffa10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900025c62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by sshd/5796:
3 locks held by syz-executor/5799:
4 locks held by kworker/u8:3/5840:
 #0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000350fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.435/7521:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.435/7522:
 #0: ffffffff99e41cb8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.0.501/7800:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.0.501/7807:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.3.651/8475:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.686/8588:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.968/9787:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.1085/10215:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.1135/10447:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.1372/11455:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.1460/11834:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.1488/11949:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.9.1488/11950:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.1492/11979:
 #0: ffffffff8f503890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff88810ca086d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz-executor/11986:
2 locks held by syz-executor/12072:
 #0: 
ffffffff8f510488 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz-executor/12135:
2 locks held by syz.0.1528/12138:
3 locks held by syz.0.1528/12139:
1 lock held by syz.0.1528/12140:
1 lock held by syz.0.1528/12141:
2 locks held by syz.0.1528/12142:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-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+0xfee/0x1030
 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: 5249 Comm: klogd Not tainted 6.16.0-rc3-syzkaller-00159-g223e2288f4b8-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:do_raw_spin_lock+0x7d/0x290
Code: 4c 24 20 48 c1 e9 03 48 b8 f1 f1 f1 f1 04 f3 f3 f3 48 89 4c 24 18 4a 89 04 39 4c 8d 77 04 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 9f 01 00 00 41 8b 06 3d ad 4e ad de 0f 85 1b 01 00 00
RSP: 0000:ffffc9000272e740 EFLAGS: 00000807
RAX: 0000000000000000 RBX: ffffffff99dc9720 RCX: 1ffff920004e5cec
RDX: 0000000000000000 RSI: ffffffff8db70975 RDI: ffffffff99dc9720
RBP: ffffc9000272e7f0 R08: 0000000000000000 R09: ffffffff854709be
R10: dffffc0000000000 R11: ffffffff8545fdf0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99dc9724 R15: dffffc0000000000
FS:  00007faa4f0db380(0000) GS:ffff8881a3c50000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f16854f5628 CR3: 000000010c636000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 _raw_spin_lock_irqsave+0xb3/0xf0
 serial8250_console_write+0x17e/0x1ba0
 console_flush_all+0x728/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 dump_unreclaimable_slab+0x112/0x150
 dump_header+0x39e/0x480
 oom_kill_process+0x3b6/0x950
 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+0xf3e/0x5620
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0x764/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0010:__get_user_8+0x14/0x30
Code: 00 e9 80 f9 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 ba 00 f0 ff ff ff 7f 00 00 48 39 d0 48 0f 47 c2 0f 1f 00 <48> 8b 10 31 c0 0f 1f 00 e9 4f f9 03 00 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc9000272fdd8 EFLAGS: 00010287
RAX: 00007faa4f0dbd28 RBX: ffff888110d24ef0 RCX: a035ce224c8f0700
RDX: 00007ffffffff000 RSI: ffffffff8db70975 RDI: ffffffff8be28d40
RBP: ffffc9000272fef0 R08: 0000000000000000 R09: ffffffff820c48e0
R10: dffffc0000000000 R11: fffffbfff1f4223f R12: dffffc0000000000
R13: ffffc9000272ffd8 R14: 00007faa4f0dbd28 R15: ffff888110d23980
 __rseq_handle_notify_resume+0x137/0x11f0
 irqentry_exit_to_user_mode+0x90/0x120
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7faa4f1f0503
Code: Unable to access opcode bytes at 0x7faa4f1f04d9.
RSP: 002b:00007ffe30d4b3c8 EFLAGS: 00010283
RAX: 0000000000000214 RBX: 0000000000000073 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000025 RDI: 00007faa4f3cb214
RBP: 0000555acd870910 R08: 000000000000004f R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000000 R12: 00007ffe30d4b9d8
R13: 00007faa4f3cb214 R14: 00000000ffffffb1 R15: 000000000000004f
 </TASK>
