INFO: task syz.2.3089:17326 blocked for more than 143 seconds.
Not tainted 6.16.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3089 state:D stack:28328 pid:17326 tgid:17325 ppid:16928 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
comedi_device_attach+0xc6/0x670 drivers/comedi/drivers.c:962
do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline]
comedi_unlocked_ioctl+0x686/0xfc0 drivers/comedi/comedi_fops.c:2156
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc99898e9a9
RSP: 002b:00007fc9997b2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc998bb5fa0 RCX: 00007fc99898e9a9
RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003
RBP: 00007fc998a10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc998bb5fa0 R15: 00007fff0030ddd8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5597:
#0: ffff8880353020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz.0.3098/16925:
2 locks held by syz.2.3089/17326:
#0: ffff88814c6380f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_unlocked_ioctl+0x138/0xfc0 drivers/comedi/comedi_fops.c:2144
#1: ffffffff8f3c13a8 (comedi_drivers_list_lock){+.+.}-{4:4}, at: comedi_device_attach+0xc6/0x670 drivers/comedi/drivers.c:962
3 locks held by kworker/u8:4/17601:
1 lock held by syz.3.3266/17732:
#0: ffff88814c6380f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2846
1 lock held by syz.7.3297/18161:
#0: ffff88814c6380f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2846
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 5195 Comm: klogd Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:vsnprintf+0x359/0xf00 lib/vsprintf.c:-1
Code: 00 00 41 c6 45 00 25 e9 7a 04 00 00 48 89 eb 4c 29 fb 4c 63 e3 4c 3b 6c 24 20 0f 83 e3 01 00 00 e8 4c 7b 5d f6 4c 89 74 24 08 <4c> 8b 74 24 20 4d 29 ee 4c 89 e7 4c 89 f6 e8 94 7d 5d f6 4d 39 f4
RSP: 0018:ffffc900030f77f0 EFLAGS: 00000293
RAX: ffffffff8b62aa74 RBX: 0000000000000001 RCX: ffff888068450000
RDX: 0000000000000000 RSI: ffffffff8f87bee0 RDI: 0000000000000000
RBP: ffffffff8b8b8926 R08: ffff888068450000 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000001
R13: ffffc900030f7ac9 R14: 0000000000000800 R15: ffffffff8b8b8925
FS: 00007f88be000c80(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fabce7d538 CR3: 00000000336b0000 CR4: 00000000003526f0
Call Trace:
sprintf+0xd9/0x120 lib/vsprintf.c:3037
print_time kernel/printk/printk.c:1381 [inline]
info_print_prefix+0x155/0x310 kernel/printk/printk.c:1407
record_print_text+0x154/0x430 kernel/printk/printk.c:1456
syslog_print+0x34f/0x590 kernel/printk/printk.c:1667
do_syslog+0x544/0x760 kernel/printk/printk.c:1785
__do_sys_syslog kernel/printk/printk.c:1877 [inline]
__se_sys_syslog kernel/printk/printk.c:1875 [inline]
__x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1875
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f88be1caa37
Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007fff1ff410c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000067
RAX: ffffffffffffffda RBX: 00007f88be36a490 RCX: 00007f88be1caa37
RDX: 00000000000003ff RSI: 00007f88be36a490 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000206 R12: 00007f88be36a490
R13: 00007f88be347dfe R14: 00007f88be36a865 R15: 00007f88be36a865