INFO: task syz.5.895:9200 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.895       state:D stack:26808 pid:9200  tgid:9183  ppid:8520   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x16ec/0x5620 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153
 __flush_work+0x9e0/0xda0 kernel/workqueue.c:4366
 p9_mux_poll_stop net/9p/trans_fd.c:140 [inline]
 p9_conn_destroy net/9p/trans_fd.c:804 [inline]
 p9_fd_close+0x226/0x400 net/9p/trans_fd.c:840
 p9_client_create+0x6b4/0xcc0 net/9p/client.c:937
 v9fs_session_init+0x46/0xe60 fs/9p/v9fs.c:446
 v9fs_get_tree+0xbd/0xac0 fs/9p/vfs_super.c:97
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f710aface59
RSP: 002b:00007f7108da1028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f710b226270 RCX: 00007f710aface59
RDX: 0000200000000080 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f710b042d6f R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f710b226308 R14: 00007f710b226270 R15: 00007ffe52b1af18
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/1:0/31:
 #0: ffff88801faf1938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801faf1938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90000a5fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90000a5fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff88802b7cc210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802b7cc210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899
 #3: ffff88802b7c7658 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 #3: ffff88802b7c7658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
 #3: ffff88802b7c7658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #3: ffff88802b7c7658 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #3: ffff88802b7c7658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b0/0x4f60 drivers/usb/core/hub.c:5953
 #4: ffff888028727f58 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
 #4: ffff888028727f58 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #4: ffff888028727f58 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #4: ffff888028727f58 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e0/0x4f60 drivers/usb/core/hub.c:5953
2 locks held by kworker/1:1/36:
 #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90000ab7c40 (p9_poll_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90000ab7c40 (p9_poll_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/119:
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90002f5fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90002f5fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
3 locks held by kworker/u8:18/1470:
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90006867c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90006867c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
4 locks held by kworker/u8:24/1476:
 #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90006927c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90006927c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f340fa0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
 #3: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248
2 locks held by getty/5373:
 #0: ffff888036aed0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5618:
 #0: ffff888034c38480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888032f88b00 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
 #1: ffff888032f88b00 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline]
 #1: ffff888032f88b00 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline]
 #1: ffff888032f88b00 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5414
9 locks held by syz-executor/5621:
3 locks held by kworker/1:5/8814:
 #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90021757c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90021757c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by udevd/9149:
 #0: ffff888037644480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
1 lock held by syz-executor/10384:
 #0: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
2 locks held by syz.3.1200/10408:
1 lock held by dhcpcd-run-hook/10445:
 #0: ffff88803efd80d8 (&pipe->rd_wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #0: ffff88803efd80d8 (&pipe->rd_wait){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394
3 locks held by syz.3.1213/10458:
1 lock held by syz.3.1213/10459:
 #0: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f34fcf8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
2 locks held by sed/10457:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10458 Comm: syz.3.1213 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 83 13 f6 cc
RSP: 0018:ffffc90007aa73a8 EFLAGS: 00000056
RAX: ffff88801dad1101 RBX: ffff88801a047364 RCX: ffffffff819dafa1
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801dad1168
RBP: 0000000000000007 R08: ffff88801dad116b R09: 1ffff11003b5a22d
R10: dffffc0000000000 R11: ffffed1003b5a22e R12: 1ffff11003408e6c
R13: ffff88801dad1168 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f638845d6c0(0000) GS:ffff888126283000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f638845cff8 CR3: 00000000781a0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
 cpupri_set+0x141/0x1f0 kernel/sched/cpupri.c:265
 inc_rt_prio_smp kernel/sched/rt.c:1061 [inline]
 inc_rt_prio kernel/sched/rt.c:1087 [inline]
 inc_rt_tasks kernel/sched/rt.c:1183 [inline]
 __enqueue_rt_entity kernel/sched/rt.c:1362 [inline]
 enqueue_rt_entity kernel/sched/rt.c:1411 [inline]
 enqueue_task_rt+0x54a/0xd20 kernel/sched/rt.c:1446
 enqueue_task+0x75/0x410 kernel/sched/core.c:2165
 activate_task kernel/sched/core.c:2205 [inline]
 ttwu_do_activate+0x1cc/0x660 kernel/sched/core.c:3725
 ttwu_queue kernel/sched/core.c:3978 [inline]
 try_to_wake_up+0x724/0x1380 kernel/sched/core.c:4302
 rt_mutex_wake_up_q kernel/locking/rtmutex.c:572 [inline]
 rt_mutex_slowunlock+0x5b8/0x8b0 kernel/locking/rtmutex.c:1478
 spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
 __wake_up_common_lock+0x18a/0x1e0 kernel/sched/wait.c:127
 __unix_dgram_recvmsg+0x485/0xd60 net/unix/af_unix.c:2612
 sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1137
 ____sys_recvmsg+0x3ef/0x4b0 net/socket.c:2916
 ___sys_recvmsg+0x215/0x590 net/socket.c:2960
 do_recvmmsg+0x33a/0x800 net/socket.c:3055
 __sys_recvmmsg net/socket.c:3129 [inline]
 __do_sys_recvmmsg net/socket.c:3152 [inline]
 __se_sys_recvmmsg net/socket.c:3145 [inline]
 __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3145
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f638a22ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f638845d028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f638a4a6090 RCX: 00007f638a22ce59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f638a2c2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f638a4a6128 R14: 00007f638a4a6090 R15: 00007ffda2d4f8e8
 </TASK>