INFO: task syz.4.21:401 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21 state:D
stack:0 pid:401 tgid:401 ppid:394 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:6052 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7865
__schedule_loop kernel/sched/core.c:7942 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7957
schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x368/0x650 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
__flush_work+0x6a8/0xaa0 kernel/workqueue.c:4290
__cancel_work_sync kernel/workqueue.c:4411 [inline]
cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4448
uhid_dev_destroy drivers/hid/uhid.c:584 [inline]
uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662
__fput+0x208/0xa30 fs/file_table.c:447
____fput+0x20/0x30 fs/file_table.c:475
task_work_run+0x1e8/0x260 kernel/task_work.c:246
resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x63/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ff91ab9de59
RSP: 002b:00007fffad764e18 EFLAGS: 00000246
ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fffad764f00 RCX: 00007ff91ab9de59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000002aa14 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2c920000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff91ae25fac R14: 00007ff91ae25fa8 R15: 00007ff91ae25fa0
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 c9311b6cb369b61e24bd82353f907fc301b53255
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xe45/0xf90 kernel/hung_task.c:423
kthread+0x2c7/0x360 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted syzkaller #0 c9311b6cb369b61e24bd82353f907fc301b53255
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events uhid_device_add_worker
RIP: 0010:io_serial_out+0x85/0xd0 drivers/tty/serial/8250/8250_port.c:413
Code: fe 44 89 e1 41 d3 e6 49 83 c7 08 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 54 46 bd fe 45 03 37 89 d8 44 89 f2 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 e1 80 e1 07
RSP: 0018:ffffc900000b6e48 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc900000b6e70 R08: 0000000000000003 R09: 0000000000000004
R10: 0000000000000000 R11: ffffffff8322dc60 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000000003f9 R15: ffffffff88c38488
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555695974e8 CR3: 000000010cf6a000 CR4: 00000000003526b0
Call Trace:
serial_out drivers/tty/serial/8250/8250.h:142 [inline]
serial8250_clear_IER drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x3a5/0x2150 drivers/tty/serial/8250/8250_port.c:3392
univ8250_console_write+0x71/0xb0 drivers/tty/serial/8250/8250_core.c:396
console_emit_next_record kernel/printk/printk.c:3151 [inline]
console_flush_all+0x5e6/0xab0 kernel/printk/printk.c:3239
__console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
console_unlock+0xf8/0x2c0 kernel/printk/printk.c:3338
vprintk_emit+0x282/0x650 kernel/printk/printk.c:2462
dev_vprintk_emit+0x33c/0x400 drivers/base/core.c:4962
dev_printk_emit+0xef/0x150 drivers/base/core.c:4973
__dev_printk+0x17f/0x1b0 drivers/base/core.c:4985
_dev_warn+0x11f/0x180 drivers/base/core.c:5029
hid_parser_main+0x84d/0xde0 drivers/hid/hid-core.c:667
hid_open_report+0x87f/0x1120 drivers/hid/hid-core.c:1313
hid_parse include/linux/hid.h:1139 [inline]
hid_generic_probe+0x42/0x90 drivers/hid/hid-generic.c:66
__hid_device_probe drivers/hid/hid-core.c:2753 [inline]
hid_device_probe+0x2d1/0x5f0 drivers/hid/hid-core.c:2790
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2e1/0x8b0 drivers/base/dd.c:657
__driver_probe_device+0x193/0x280 drivers/base/dd.c:799
driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
__device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459
__device_attach+0x2c4/0x3c0 drivers/base/dd.c:1029
device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
device_add+0x7fd/0xbf0 drivers/base/core.c:3692
hid_add_device+0x3c4/0x5a0 drivers/hid/hid-core.c:2936
uhid_device_add_worker+0x49/0xf0 drivers/hid/uhid.c:73
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c7/0x360 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244