INFO: task syz.3.270:7039 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.270 state:D stack:25320 pid:7039 ppid:5778 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x2cb/0x5b0 kernel/sched/completion.c:148
__flush_work+0x913/0xaa0 kernel/workqueue.c:3471
__cancel_work_timer+0x3f8/0x560 kernel/workqueue.c:3558
uhid_dev_destroy drivers/hid/uhid.c:585 [inline]
uhid_char_release+0xaf/0x600 drivers/hid/uhid.c:663
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1d4/0x260 kernel/task_work.c:245
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f93a859ce59
RSP: 002b:00007fff4cdf3c98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fff4cdf3d80 RCX: 00007f93a859ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000003b6a3 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2ce20000 R11: 0000000000000246 R12: 00007fff4cdf3dc0
R13: 00007f93a8815fac R14: 000000000003b73e R15: 00007f93a8815fa0
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d132120 (
rcu_read_lock){....}-{1:2}
, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5531:
#0: ffff88803189a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5776:
3 locks held by kworker/0:4/5857:
7 locks held by kworker/0:5/5858:
2 locks held by kworker/u4:16/5973:
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90004f37d00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90004f37d00 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
2 locks held by kworker/u4:19/5987:
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90004fe7d00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90004fe7d00 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5858 Comm: kworker/0:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events uhid_device_add_worker
RIP: 0010:io_serial_in+0x77/0xb0 drivers/tty/serial/8250/8250_port.c:417
Code: e8 9e 31 de 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 cf 70 36 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:ffffc9000479ed38 EFLAGS: 00000002
RAX: 1ffffffff2ec0c00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc9000479ef30 R08: ffff8880210c0237 R09: 1ffff11004218046
R10: dffffc0000000000 R11: ffffed1004218047 R12: dffffc0000000000
R13: 00000000000026dc R14: ffffffff976061e0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbcf0bea540 CR3: 0000000018aa5000 CR4: 00000000003506f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:117 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:139 [inline]
wait_for_lsr drivers/tty/serial/8250/8250_port.c:2084 [inline]
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3373 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3395 [inline]
serial8250_console_write+0xf78/0x17f0 drivers/tty/serial/8250/8250_port.c:3480
console_emit_next_record kernel/printk/printk.c:2944 [inline]
console_flush_all+0x6db/0xd20 kernel/printk/printk.c:3000
console_unlock+0xad/0x350 kernel/printk/printk.c:3069
vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
dev_vprintk_emit+0x356/0x410 drivers/base/core.c:4968
dev_printk_emit+0xef/0x140 drivers/base/core.c:4979
_dev_warn+0x11f/0x170 drivers/base/core.c:5035
hid_parser_main+0x83b/0xbf0 drivers/hid/hid-core.c:632
hid_open_report+0x861/0xee0 drivers/hid/hid-core.c:1278
hid_parse include/linux/hid.h:1122 [inline]
hid_generic_probe+0x3d/0x80 drivers/hid/hid-generic.c:66
__hid_device_probe drivers/hid/hid-core.c:2652 [inline]
hid_device_probe+0x293/0x5b0 drivers/hid/hid-core.c:2689
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb20 drivers/base/dd.c:658
__driver_probe_device+0x1ef/0x390 drivers/base/dd.c:820
driver_probe_device+0x4f/0x420 drivers/base/dd.c:850
__device_attach_driver+0x2ca/0x510 drivers/base/dd.c:978
bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
__device_attach+0x2c2/0x420 drivers/base/dd.c:1050
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x88e/0xc50 drivers/base/core.c:3698
hid_add_device+0x38d/0x530 drivers/hid/hid-core.c:2835
uhid_device_add_worker+0x43/0xe0 drivers/hid/uhid.c:73
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293