INFO: task kworker/1:4:5689 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:4 state:D stack:21976 pid:5689 tgid:5689 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7362
usb_kill_urb drivers/usb/core/urb.c:717 [inline]
usb_kill_urb+0x253/0x320 drivers/usb/core/urb.c:703
usb_start_wait_urb+0x2c3/0x580 drivers/usb/core/message.c:74
usb_internal_control_msg drivers/usb/core/message.c:117 [inline]
usb_control_msg+0x328/0x4b0 drivers/usb/core/message.c:167
get_bMaxPacketSize0.constprop.0+0xd0/0x1f0 drivers/usb/core/hub.c:4864
hub_port_init+0xb3a/0x37f0 drivers/usb/core/hub.c:5125
hub_port_connect drivers/usb/core/hub.c:5509 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
port_event drivers/usb/core/hub.c:5884 [inline]
hub_event+0x2ead/0x4420 drivers/usb/core/hub.c:5966
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
process_scheduled_works kernel/workqueue.c:3470 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#1:
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6837
locks held by kworker/u8:9/3302: 9, last CPU#0:
#0: ffff88802cd8c140 ((wq_completion)wg-kex-wg2#11){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
#1: ffffc9000eeb7d08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
#2: ffff888056cfdaa0 (&peer->endpoint_lock){++-.}-{3:3}, at: wg_socket_send_skb_to_peer+0x5f/0x210 drivers/net/wireguard/socket.c:172
#3: ffffffff8edec000 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#3: ffffffff8edec000 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:902 [inline]
#3: ffffffff8edec000 (rcu_read_lock_bh){....}-{1:3}, at: send6+0x303/0xc40 drivers/net/wireguard/socket.c:118
#4: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#4: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#4: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: ip6_dst_lookup_tail.constprop.0+0x1011/0x2110 net/ipv6/ip6_output.c:1163
#5: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#5: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#5: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: ip6_route_get_saddr include/net/ip6_route.h:155 [inline]
#5: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: ip6_dst_lookup_tail.constprop.0+0xb77/0x2110 net/ipv6/ip6_output.c:1165
#6: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#6: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#6: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: ipv6_dev_get_saddr+0x18f/0xd20 net/ipv6/addrconf.c:1845
#7: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#7: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#7: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: ipv6_addr_label+0x36/0x270 net/ipv6/addrlabel.c:142
#8: ffff8880b8428518 (hrtimer_bases.lock){-.-.}-{2:2}, at: class_raw_spinlock_constructor include/linux/spinlock.h:558 [inline]
#8: ffff8880b8428518 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_rearm_deferred+0xb9/0x7b0 kernel/time/hrtimer.c:2181
locks held by getty/5361: 2, on CPU#1:
#0: ffff88801d7800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by kworker/1:4/5689: 5, on CPU#1:
#0: ffff888021e95940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
#1: ffffc90005137d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
#2: ffff88802d03f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802d03f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4420 drivers/usb/core/hub.c:5912
#3: ffff88802d03c568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3265 [inline]
#3: ffff88802d03c568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5477 [inline]
#3: ffff88802d03c568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
#3: ffff88802d03c568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5884 [inline]
#3: ffff88802d03c568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2b3e/0x4420 drivers/usb/core/hub.c:5966
#4: ffff88802ce55960 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5478 [inline]
#4: ffff88802ce55960 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
#4: ffff88802ce55960 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5884 [inline]
#4: ffff88802ce55960 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2b67/0x4420 drivers/usb/core/hub.c:5966
locks held by syz.4.2429/13555: 1, last CPU#1:
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by syz.1.2436/13571: 2, last CPU#1:
#0: ffff888021f10460 (sb_writers#6){.+.+}-{0:0}, at: get_signal+0x1f2a/0x21e0 kernel/signal.c:3024
#1: ffff888028c714a0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff888028c714a0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x86/0x140 mm/shmem.c:3430
locks held by syz.5.2444/13599: 2, last CPU#1:
#0: ffff8880369d2460 (sb_writers#6){.+.+}-{0:0}, at: get_signal+0x1f2a/0x21e0 kernel/signal.c:3024
#1: ffff88804c4f0e98 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88804c4f0e98 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x86/0x140 mm/shmem.c:3430
locks held by syz.4.2457/13625: 1, on CPU#0:
#0: ffff88802bb95038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff88802bb95038 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
locks held by syz.4.2457/13626: 1, last CPU#0:
#0: ffff88802bb95038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff88802bb95038 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x229/0x3a0 mm/gup.c:1942
locks held by syz.3.2460/13635: 2, last CPU#1:
#0: ffff888028958460 (sb_writers#6){.+.+}-{0:0}, at: get_signal+0x1f2a/0x21e0 kernel/signal.c:3024
#1: ffff88807ff69aa8 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88807ff69aa8 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x86/0x140 mm/shmem.c:3430
locks held by syz.1.2461/13636: 2, last CPU#0:
#0: ffff888076a82bc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 24 5c fc 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 c8 37 cf fc eb a2 e8 51 38
RSP: 0018:ffffc90000157958 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff85afc750 RDI: ffffffff9bc60ca0
RBP: ffffffff9bc60c60 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 205d323354202020 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff378c1e9 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888123b64000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000440 CR3: 000000002e3f1000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2013
serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3270
__serial8250_console_fifo_write+0xa5/0x290 drivers/tty/serial/8250/8250_port.c:3345
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xf46/0x1330 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245