INFO: task syz.3.155:6455 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.155       state:D stack:26448 pid:6455  ppid:5763   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
 chrdev_open+0x59e/0x670 fs/char_dev.c:414
 do_dentry_open+0x8c6/0x1500 fs/open.c:929
 do_open fs/namei.c:3640 [inline]
 path_openat+0x274b/0x3190 fs/namei.c:3797
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2d2378f749
RSP: 002b:00007f2d24556038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2d239e6090 RCX: 00007f2d2378f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f2d23813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2d239e6128 R14: 00007f2d239e6090 R15: 00007ffddec6ad68
 </TASK>
INFO: task syz.1.167:6502 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.167       state:D stack:26888 pid:6502  ppid:5764   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
 chrdev_open+0x59e/0x670 fs/char_dev.c:414
 do_dentry_open+0x8c6/0x1500 fs/open.c:929
 do_open fs/namei.c:3640 [inline]
 path_openat+0x274b/0x3190 fs/namei.c:3797
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff2cd98f749
RSP: 002b:00007ff2ce85a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff2cdbe6270 RCX: 00007ff2cd98f749
RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007ff2cda13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff2cdbe6308 R14: 00007ff2cdbe6270 R15: 00007fff13716ad8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:1/12:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
5 locks held by kworker/u4:4/59:
3 locks held by kworker/u4:8/2933:
4 locks held by kworker/u4:9/2946:
1 lock held by udevd/5137:
2 locks held by getty/5529:
 #0: ffff88803128a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by syz.0.49/6060:
1 lock held by syz.3.155/6455:
 #0: ffff88802ba930f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
1 lock held by syz.1.167/6502:
 #0: ffff88802ba930f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
1 lock held by syz.2.207/6688:
 #0: ffff88802ba930f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
1 lock held by syz.4.312/7120:
 #0: ffff88802ba930f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
1 lock held by syz.6.363/7305:
 #0: ffff88802ba930f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816
1 lock held by dhcpcd-run-hook/7954:

=============================================

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 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7954 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:reacquire_held_locks+0x0/0x5a0 kernel/locking/lockdep.c:5271
Code: e8 e5 0c 75 00 e9 fb fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 4c ff ff ff e8 cb 0c 75 00 e9 42 ff ff ff 66 0f 1f 44 00 00 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0000:ffffc900044ffc18 EFLAGS: 00000003
RAX: 1ffff1100fda08da RBX: ffffffffffffffff RCX: ffffc900044ffc7c
RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88807ed03c00
RBP: ffffc900044ffd30 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: ffff88807ed046e0
R13: dffffc0000000000 R14: ffff88807ed046d0 R15: 1ffff9200089ff90
FS:  00007fafa65d1c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcf74f7a08 CR3: 000000004e053000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 __lock_release kernel/locking/lockdep.c:5468 [inline]
 lock_release+0x32b/0x8b0 kernel/locking/lockdep.c:5774
 rcu_lock_release include/linux/rcupdate.h:344 [inline]
 rcu_read_unlock include/linux/rcupdate.h:819 [inline]
 lock_vma_under_rcu+0x526/0x650 mm/memory.c:-1
 do_user_addr_fault+0x318/0x12e0 arch/x86/mm/fault.c:1316
 handle_page_fault arch/x86/mm/fault.c:1465 [inline]
 exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fafa676b678
Code: 18 00 00 00 48 8d b8 e0 02 00 00 66 48 0f 6e c7 66 0f 6c c0 0f 11 80 d8 02 00 00 b8 11 01 00 00 0f 05 e8 1b 0e f7 ff 48 89 df <e8> 63 e8 f6 ff 48 83 c4 18 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00
RSP: 002b:00007ffcf74f7a10 EFLAGS: 00010206
RAX: 0000000000001f1b RBX: 00007ffcf74f7a18 RCX: 00007fafa676b636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffcf74f7a18
RBP: 0000000000001f1b R08: 0000000000000000 R09: 0000000000000030
R10: 00007fafa65d1f50 R11: 0000000000000246 R12: 0000563a9a6d9290
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>