INFO: task syz-executor134:5875 blocked for more than 143 seconds. Not tainted 6.16.0-next-20250731-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor134 state:D stack:27432 pid:5875 tgid:5875 ppid:5873 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2863 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 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: 0033:0x7fdde9fa4969 RSP: 002b:00007ffd948445d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffd94844610 RCX: 00007fdde9fa4969 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000f4240 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007ffd94844898 R14: 00007ffd948445fc R15: 00007ffd94844600 INFO: task syz-executor134:5877 blocked for more than 143 seconds. Not tainted 6.16.0-next-20250731-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor134 state:D stack:28040 pid:5877 tgid:5877 ppid:5874 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2863 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 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: 0033:0x7fdde9fa4969 RSP: 002b:00007ffd948445d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffd94844610 RCX: 00007fdde9fa4969 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000f4240 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007ffd94844898 R14: 00007ffd948445fc R15: 00007ffd94844600 INFO: task syz-executor134:5878 blocked for more than 144 seconds. Not tainted 6.16.0-next-20250731-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor134 state:D stack:27704 pid:5878 tgid:5878 ppid:5876 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2863 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 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: 0033:0x7fdde9fa4969 RSP: 002b:00007ffd948445d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffd94844610 RCX: 00007fdde9fa4969 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000f4240 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007ffd94844898 R14: 00007ffd948445fc R15: 00007ffd94844600 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e539f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e539f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e539f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5604: #0: ffff88814ca930a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor134/5872: 1 lock held by syz-executor134/5875: #0: ffff88802f62a0f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2863 1 lock held by syz-executor134/5877: #0: ffff88802f62a0f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2863 1 lock held by syz-executor134/5878: #0: ffff88802f62a0f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2863 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-next-20250731-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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: kworker/u8:3 Not tainted 6.16.0-next-20250731-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:trace_hardirqs_on+0xb/0x40 kernel/trace/trace_preemptirq.c:72 Code: 00 ff ff ff 90 0f 0b 90 e9 77 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 75 d3 1a 11 <85> c0 74 14 48 8b 3c 24 e8 c8 fe ff ff 65 c7 05 5d d3 1a 11 00 00 RSP: 0018:ffffc90000ad76b8 EFLAGS: 00000093 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff8881432e3c00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000ad7810 R08: 0000000000000001 R09: 0000000000ad7800 R10: dffffc0000000000 R11: ffffed100350e0ec R12: dffffc0000000000 R13: ffff88801a87c558 R14: 0000000000000200 R15: ffffffff821879e3 FS: 0000000000000000(0000) GS:ffff88812590a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564ce03c2168 CR3: 000000000e336000 CR4: 00000000003526f0 Call Trace: __text_poke+0x748/0xa10 arch/x86/kernel/alternative.c:2564 text_poke arch/x86/kernel/alternative.c:2589 [inline] smp_text_poke_batch_finish+0xd0f/0x1130 arch/x86/kernel/alternative.c:2978 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:855 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.152 msecs