INFO: task kworker/0:2:796 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/0:2 state:D stack:21856 pid:796 tgid:796 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
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
i2c_del_adapter+0x5c0/0x790 drivers/i2c/i2c-core-base.c:1814
release_nodes drivers/base/devres.c:505 [inline]
devres_release_group+0x2fd/0x350 drivers/base/devres.c:692
hid_device_remove+0x250/0x370 drivers/hid/hid-core.c:2836
device_remove drivers/base/dd.c:571 [inline]
__device_release_driver drivers/base/dd.c:1284 [inline]
device_release_driver_internal+0x46f/0x860 drivers/base/dd.c:1307
bus_remove_device+0x34d/0x440 drivers/base/bus.c:616
device_del+0x527/0x8f0 drivers/base/core.c:3878
hid_remove_device drivers/hid/hid-core.c:3008 [inline]
hid_destroy_device+0x6b/0x1b0 drivers/hid/hid-core.c:3030
usbhid_disconnect+0x9f/0xc0 drivers/hid/usbhid/hid-core.c:1477
usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:573 [inline]
__device_release_driver drivers/base/dd.c:1284 [inline]
device_release_driver_internal+0x4d9/0x860 drivers/base/dd.c:1307
bus_remove_device+0x34d/0x440 drivers/base/bus.c:616
device_del+0x527/0x8f0 drivers/base/core.c:3878
usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1418
usb_disconnect+0x32f/0x990 drivers/usb/core/hub.c:2345
hub_port_connect drivers/usb/core/hub.c:5407 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1cc9/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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:
1 lock held by khungtaskd/30:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/0:2/796:
#0: ffff8880212d3148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff8880212d3148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90003dd7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90003dd7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffff888029316198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888029316198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff8880281ee198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff8880281ee198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x990 drivers/usb/core/hub.c:2336
#4: ffff888078cd8160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff888078cd8160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff888078cd8160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304
#5: ffff888078b09a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#5: ffff888078b09a20 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#5: ffff888078b09a20 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304
2 locks held by getty/5584:
#0: ffff8880368f40a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz.1.2158/14043:
1 lock held by syz.8.2160/14049:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
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:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 5175 Comm: syslogd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:page_slab mm/slab.h:137 [inline]
RIP: 0010:kfree+0x7f/0x630 mm/slub.c:6478
Code: 49 83 fc 11 0f 82 f9 02 00 00 48 8b 1d d2 8a f6 0b 4c 89 e7 e8 f2 87 54 ff 48 c1 e8 06 48 83 e0 c0 48 8d 3c 03 48 8b 44 03 08 <49> 89 c6 49 ff ce a8 01 4c 0f 44 f7 41 0f b6 46 33 c1 e0 18 3d 00
RSP: 0018:ffffc90002fd7888 EFLAGS: 00000206
RAX: ffff88813fe00140 RBX: ffffea0000000000 RCX: ffff88807f645b80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea00014f8f00
RBP: 00000000000000c0 R08: ffff88807ed73fe7 R09: 1ffff1100fdae7fc
R10: dffffc0000000000 R11: ffffed100fdae7fd R12: ffff888053e3c800
R13: ffffffff8974d820 R14: ffff888053e3c800 R15: dffffc0000000000
FS: 00007f0fc928ac80(0000) GS:ffff888125461000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6f59e82f8 CR3: 000000007f74c000 CR4: 00000000003526f0
Call Trace:
skb_kfree_head net/core/skbuff.c:1089 [inline]
skb_free_head net/core/skbuff.c:1101 [inline]
skb_release_data+0x6f0/0x940 net/core/skbuff.c:1128
skb_release_all net/core/skbuff.c:1203 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1217
__unix_dgram_recvmsg+0x9d0/0xd50 net/unix/af_unix.c:2653
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x172/0x1b0 net/socket.c:1100
sock_read_iter+0x251/0x320 net/socket.c:1170
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x582/0xa70 fs/read_write.c:574
ksys_read+0x150/0x270 fs/read_write.c:717
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fc93da407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffebd5f5100 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f0fc928ac80 RCX: 00007f0fc93da407
RDX: 00000000000000ff RSI: 000055e64e0c4950 RDI: 0000000000000000
RBP: 000055e64e0c4910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055e64e0c4989
R13: 0000000000000000 R14: 000055e64e0c4950 R15: 000055e6196b2d98