INFO: task kworker/1:1:34 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1 state:D
stack:22992 pid:34 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x2c2/0x590 kernel/sched/completion.c:138
i2c_del_adapter+0x2d6/0x430 drivers/i2c/i2c-core-base.c:1849
osif_disconnect+0x42/0x80 drivers/i2c/busses/i2c-robotfuzz-osif.c:185
usb_unbind_interface+0x200/0x870 drivers/usb/core/driver.c:457
__device_release_driver drivers/base/dd.c:1294 [inline]
device_release_driver_internal+0x6eb/0x7c0 drivers/base/dd.c:1305
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3900
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2319
hub_port_connect drivers/usb/core/hub.c:5366 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5662 [inline]
port_event drivers/usb/core/hub.c:5822 [inline]
hub_event+0x1d27/0x5200 drivers/usb/core/hub.c:5904
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d92e230 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d92ea50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
4 locks held by kworker/1:1/34:
2 locks held by getty/4023:
#0: ffff8880311cc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
3 locks held by kworker/u4:5/4301:
3 locks held by kworker/0:5/4369:
#0: ffff888018470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900046bfd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffffffff8d933578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#2: ffffffff8d933578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
2 locks held by kworker/0:7/4652:
#0: ffff888018470938 (
(wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc9000547fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/0:18/13786:
#0: ffff888018472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1:
ffffc90003497d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
3 locks held by kworker/1:16/14314:
2 locks held by syz.4.3114/15440:
#0: ffffffff8eb566e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8eb566e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3506
#1: ffffffff8d933578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8d933578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 34 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461
Code: e8 22 1e fa fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 f3 79 4b fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c
RSP: 0018:ffffc90000ab6fd8 EFLAGS: 00000006
RAX: 1ffffffff2fb8405 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 00000000000fffff RDI: 0000000000100000
RBP: ffffc90000ab71b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000156ddc R12: dffffc0000000000
R13: ffffffff97a7de00 R14: ffffffff97dc2140 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000003df030 CR3: 0000000031fa3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_port_in include/linux/serial_core.h:668 [inline]
serial8250_console_write+0x280/0x18b0 drivers/tty/serial/8250/8250_port.c:3450
call_console_driver kernel/printk/printk.c:1977 [inline]
console_emit_next_record+0x795/0xb50 kernel/printk/printk.c:2777
console_flush_all kernel/printk/printk.c:-1 [inline]
console_unlock+0x223/0x630 kernel/printk/printk.c:2906
vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
dev_vprintk_emit+0x32c/0x3de drivers/base/core.c:4948
dev_printk_emit+0xeb/0x139 drivers/base/core.c:4959
__dynamic_dev_dbg+0x200/0x2b0 lib/dynamic_debug.c:900
hub_port_debounce+0x2f4/0x300 drivers/usb/core/hub.c:4681
hub_port_debounce_be_stable drivers/usb/core/hub.h:173 [inline]
hub_port_connect drivers/usb/core/hub.c:5378 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5662 [inline]
port_event drivers/usb/core/hub.c:5822 [inline]
hub_event+0x1dc5/0x5200 drivers/usb/core/hub.c:5904
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
virtqueue callback for ffff888025211200 (ffffffff858ab7a0)
net_ratelimit: 15 callbacks suppressed
wireguard: wg0: Sending keepalive packet to peer 32 ([::1]:20003/0%0)
nf_conntrack: new packet for ffff88807d362900
No more buffers in queue
Receiving skb proto 0x0806 len 28 type 1
No more buffers in queue
No more buffers in queue
eth0: xmit ffff888078005a00 42:01:0a:80:00:01
Added buffer head 6 to ffff888025211400
virtqueue callback for ffff888025211400 (ffffffff858ab890)
Sent skb ffff888078005a00
No more buffers in queue
virtqueue callback for ffff888140185400 (ffffffff85445db0)
sd 0:0:1:0: cmd ffff8880281ec420 response 0 status 0x0 sense_len 0
sd 0:0:1:0: cmd ffff8880281dc060 response 0 status 0x0 sense_len 0
sd 0:0:1:0: cmd ffff8880281e53a0 response 0 status 0x0 sense_len 0
sd 0:0:1:0: cmd ffff8880281e5760 response 0 status 0x0 sense_len 0
No more buffers in queue
virtqueue callback for ffff888025211400 (ffffffff858ab890)
virtqueue callback for ffff88801ae85400 (ffffffff84767210)
virtqueue interrupt with no work for ffff88801ae85200
virtqueue interrupt with no work for ffff88801ae85000
virtqueue callback for ffff888140185400 (ffffffff85445db0)
sd 0:0:1:0: cmd ffff888026f29920 response 0 status 0x0 sense_len 0
sd 0:0:1:0: cmd ffff8880281eb160 response 0 status 0x0 sense_len 0
sd 0:0:1:0: cmd ffff8880281eb520 response 0 status 0x0 sense_len 0
No more buffers in queue
Sent skb ffff888077e6e780
No more buffers in queue
wireguard: wg1: Receiving keepalive packet from peer 33 (127.0.0.1:20001)
virtqueue callback for ffff888140185400 (ffffffff85445db0)
sd 0:0:1:0: cmd ffff8880281d0120 response 0 status 0x0 sense_len 0
No more buffers in queue
wireguard: wg1: Receiving keepalive packet from peer 46 (127.0.0.1:20003)
wireguard: wg1: Receiving keepalive packet from peer 45 ([::1]:20001/0%0)
wireguard: wg0: Receiving keepalive packet from peer 44 ([::1]:20003/0%0)
wireguard: wg1: Receiving keepalive packet from peer 39 (127.0.0.1:20001)
wireguard: wg2: Receiving keepalive packet from peer 35 ([::1]:20001/0%0)
wireguard: wg2: Receiving keepalive packet from peer 47 ([::1]:20001/0%0)
wireguard: wg2: Receiving keepalive packet from peer 41 ([::1]:20001/0%0)