INFO: task kworker/u8:0:12 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/u8:0    state:D stack:22600 pid:12    tgid:12    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.0.968:9182 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.0.968       state:D stack:23736 pid:9182  tgid:9176  ppid:5818   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: 0033:0x7f718ff8e929
RSP: 002b:00007f7190d8a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f71901b6080 RCX: 00007f718ff8e929
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000009
RBP: 00007f7190010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f71901b6080 R15: 00007fffefc76ee8
 </TASK>
INFO: task syz.3.1205:9953 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.3.1205      state:D stack:25000 pid:9953  tgid:9946  ppid:9862   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: 0033:0x7f8ccc58e929
RSP: 002b:00007f8ccd316038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f8ccc7b6160 RCX: 00007f8ccc58e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040020000
RBP: 00007f8ccc610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8ccc7b6160 R15: 00007fff34500a48
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000f7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f5033d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by khungtaskd/34:
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by kcompactd1/39:
3 locks held by kworker/u11:0/54:
 #0: ffff88802d5ad148 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900007cfbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8880771b8dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
3 locks held by kworker/1:2/973:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900069cfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810f5c0240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180
2 locks held by getty/5641:
 #0: ffff888109c4a0a0 (&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
2 locks held by syz.0.968/9182:
 #0: ffffffff99e41b18 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.3.1205/9953:
 #0: ffffffff8f5033d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.1.1396/10594:
 #0: ffffffff8f5033d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.5.2365/13730:
 #0: ffffffff8f5033d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.2564/14449:
 #0: ffffffff8f5033d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.2658/14854:
 #0: ffffffff8f5033d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff8880220b86d0 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by syz-executor/15246:
 #0: ffffffff8e144840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
1 lock held by syz.8.2780/15338:
 #0: ffffffff8e144840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570

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

NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14013 Comm: kworker/u8:7 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
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:check_preemption_disabled+0x5c/0x120
Code: 2e 36 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 81 c0 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 00 9d 92 41 f6 47 2f
RSP: 0018:ffffc900029def80 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8d995ac4 RDI: ffffffff8be28d40
RBP: ffffffff81728af5 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900029df178 R11: ffffffff81ace6a0 R12: 0000000000000002
R13: ffffffff8e13ee60 R14: 0000000000000000 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff8880b8650000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005571eff96300 CR3: 000000000df38000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0xe7/0x360
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 mld_newpack+0x13c/0xc40
 add_grhead+0x5a/0x2a0
 add_grec+0x13b2/0x1670
 mld_send_initial_cr+0x22d/0x4c0
 ipv6_mc_dad_complete+0x88/0x4b0
 addrconf_dad_completed+0x6d5/0xd60
 addrconf_dad_work+0xc36/0x14b0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
