INFO: task syz.1.18:6464 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:27912 pid:6464 ppid:6299 flags:0x00004004 Call Trace: 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: 0033:0x7f0ef4d8f749 RSP: 002b:00007f0ef5baf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0ef4fe5fa0 RCX: 00007f0ef4d8f749 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f0ef4e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0ef4fe6038 R14: 00007f0ef4fe5fa0 R15: 00007ffc934fe728 INFO: task syz.3.20:6491 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.20 state:D stack:27912 pid:6491 ppid:6304 flags:0x00004004 Call Trace: 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: 0033:0x7f330f58f749 RSP: 002b:00007f33104d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f330f7e5fa0 RCX: 00007f330f58f749 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f330f613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f330f7e6038 R14: 00007f330f7e5fa0 R15: 00007ffef7f39a68 INFO: task syz.0.17:6495 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27816 pid:6495 ppid:6298 flags:0x00004004 Call Trace: 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: 0033:0x7fcc4918f749 RSP: 002b:00007fcc4a041038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fcc493e5fa0 RCX: 00007fcc4918f749 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007fcc49213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcc493e6038 R14: 00007fcc493e5fa0 R15: 00007ffdd400b428 INFO: task syz.4.21:6739 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.21 state:D stack:27368 pid:6739 ppid:6654 flags:0x00004004 Call Trace: 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: 0033:0x7f758a98f749 RSP: 002b:00007f758b8d4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f758abe5fa0 RCX: 00007f758a98f749 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f758aa13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f758abe6038 R14: 00007f758abe5fa0 R15: 00007fff92edd168 Showing all locks held in the system: 2 locks held by kworker/u4:0/11: #0: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694 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 3 locks held by kworker/u4:3/49: #0: ffff88802c4b6d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88802c4b6d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694 #2: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 4 locks held by kworker/u4:4/59: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900015a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900015a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 #3: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #3: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 3 locks held by kworker/u4:6/2937: #0: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694 #2: ffff8880b8f29598 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999 2 locks held by getty/5531: #0: ffff8880209b80a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/1:6/6291: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90003917d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90003917d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88807d929240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491 2 locks held by syz.2.19/6351: 3 locks held by kworker/0:5/6422: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900039c7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900039c7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88802503a240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491 1 lock held by syz.1.18/6464: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.3.20/6491: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.0.17/6495: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.4.21/6739: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.5.22/6854: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.6.23/6869: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.7.24/6872: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.8.25/6900: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.9.26/6954: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.2.27/6986: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.1.28/6989: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.0.29/7002: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.3.30/7032: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.4.31/7096: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.5.32/7104: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 2 locks held by kworker/0:6/7109: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900052e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900052e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 1 lock held by syz.6.33/7111: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.7.34/7140: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.8.35/7199: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.9.36/7228: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.2.37/7235: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.1.38/7249: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.0.39/7282: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.3.40/7322: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.4.41/7342: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.5.42/7363: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz.6.43/7387: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 2 locks held by syz-executor/7411: #0: ffffffff8e019f10 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1074 #1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:16515 1 lock held by syz.7.44/7421: #0: ffff88802b8c78f8 (&dev->mutex#3){+.+.}-{3:3}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2816 1 lock held by syz-executor/7424: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 2 locks held by syz-executor/7461: #0: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516 #1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: register_netdev+0x13/0x50 net/core/dev.c:10410 2 locks held by dhcpcd/7472: #0: ffff88805f4ca130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1767 [inline] #0: ffff88805f4ca130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 #1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6351 Comm: syz.2.19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:multiq3_encoder_reset drivers/comedi/drivers/multiq3.c:229 [inline] RIP: 0010:multiq3_attach+0x66f/0x940 drivers/comedi/drivers/multiq3.c:316 Code: 00 74 08 48 89 df e8 d0 a7 db f9 8b 13 83 c2 0e b0 41 ee 41 80 3c 2c 00 74 08 48 89 df e8 b9 a7 db f9 8b 13 83 c2 0e b0 38 ee <41> 80 3c 2c 00 74 08 48 89 df e8 a2 a7 db f9 8b 13 83 c2 0e b0 02 RSP: 0018:ffffc900035c7ab8 EFLAGS: 00000202 RAX: 0000000000000038 RBX: ffff88802b8c79d0 RCX: ffff888019e7bc00 RDX: 000000000000200e RSI: 0000000002018272 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000040 R09: 1ffffffff21b28b0 R10: dffffc0000000000 R11: fffffbfff21b28b1 R12: 1ffff11005718f3a R13: 0000000000d4cc98 R14: 1ffff1100b8f6092 R15: 00000000001a9994 FS: 00007f7e8cb456c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f295bbf1d68 CR3: 000000005b4ee000 CR4: 00000000003506e0 Call Trace: comedi_device_attach+0x518/0x710 drivers/comedi/drivers.c:1006 do_devconfig_ioctl drivers/comedi/comedi_fops.c:872 [inline] comedi_unlocked_ioctl+0x606/0xfe0 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 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: 0033:0x7f7e8bd8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7e8cb45038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7e8bfe5fa0 RCX: 00007f7e8bd8f749 RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003 RBP: 00007f7e8be13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7e8bfe6038 R14: 00007f7e8bfe5fa0 R15: 00007ffc7d8c8958