INFO: task syz.1.358:6926 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.358 state:D stack:28744 pid:6926 tgid:6916 ppid:5827 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5030 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018
rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707
inode_lock_nested include/linux/fs.h:1072 [inline]
__start_dirop fs/namei.c:2833 [inline]
start_dirop fs/namei.c:2844 [inline]
filename_create+0x1fb/0x360 fs/namei.c:4848
do_symlinkat+0x120/0x3c0 fs/namei.c:5503
__do_sys_symlinkat fs/namei.c:5531 [inline]
__se_sys_symlinkat fs/namei.c:5528 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:5528
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f55e958f749
RSP: 002b:00007f55ea3bf038 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f55e97e6090 RCX: 00007f55e958f749
RDX: 0000200000000200 RSI: ffffffffffffff9c RDI: 0000200000000080
RBP: 00007f55e9613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55e97e6128 R14: 00007f55e97e6090 R15: 00007ffd4ec283c8
Showing all locks held in the system:
1 lock held by ksoftirqd/0/15:
1 lock held by rcu_tasks_trace/29:
#0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647
1 lock held by khungtaskd/31:
#0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:7/778:
#0: ffff88802fc6b948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
#1:
ffffc900036a7b80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
#2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
2 locks held by getty/5591:
#0: ffff88803039b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/1:9/5976:
#0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
#1: ffffc9000495fb80 ((work_completion)(&tn->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
#2: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tipc_net_finalize_work+0x1e/0x90 net/tipc/net.c:148
5 locks held by kworker/0:9/6458:
#0: ffff8881426ef548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
#1: ffffc9000dc37b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
#2: ffff888028494198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888028494198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff888028497518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff888028497518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff888028497518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff888028497518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff888028497518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x215a/0x4ef0 drivers/usb/core/hub.c:5953
#4: ffff888028254168 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff888028254168 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff888028254168 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff888028254168 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2182/0x4ef0 drivers/usb/core/hub.c:5953
2 locks held by syz.1.358/6917:
2 locks held by syz.1.358/6926:
#0: ffff88807a992420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509
#1: ffff8880586d08f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff8880586d08f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2833 [inline]
#1: ffff8880586d08f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2844 [inline]
#1: ffff8880586d08f0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4848
3 locks held by syz.3.624/8094:
#0: ffff8880287a0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff8880287a0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715
#1: ffff8880287a00c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5314
#2: ffffffff8f444ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
#2: ffffffff8f444ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2637
2 locks held by syz.2.661/8247:
2 locks held by syz-executor/8248:
#0: ffffffff8f7e2148 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8f7e2148 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8f7e2148 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
2 locks held by syz.4.666/8260:
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964
#1: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz.4.666/8262:
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6964
1 lock held by syz.4.666/8266:
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
1 lock held by syz.4.666/8270:
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:840
4 locks held by syz.0.668/8267:
#0: ffff8880287a8ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff8880287a8ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715
#1: ffff8880287a80c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5314
#2: ffffffff8f444ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
#2: ffffffff8f444ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2637
#3: ffff88807c997338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:346 [inline]
watchdog+0xfb5/0x1000 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5976 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events tipc_net_finalize_work
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 2d a5 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6c c9 0b fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 13 42 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000495f2b0 EFLAGS: 00000002
RAX: 0000000000000031 RBX: 0000000000000031 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888024918237 R09: 1ffff11004923046
R10: dffffc0000000000 R11: ffffffff851cab90 R12: dffffc0000000000
R13: ffffffff9985a9a6 R14: ffffffff99b6f0c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125fba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562b07023000 CR3: 0000000032a86000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
vprintk_emit+0x4d3/0x5d0 kernel/printk/printk.c:2426
_printk+0xcf/0x120 kernel/printk/printk.c:2451
tipc_set_node_addr+0x1ce/0x290 net/tipc/addr.c:79
tipc_net_finalize+0xfd/0x190 net/tipc/net.c:137
tipc_net_finalize_work+0x65/0x90 net/tipc/net.c:149
process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
process_scheduled_works kernel/workqueue.c:3344 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246