INFO: task syz.7.10183:32063 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.10183 state:D stack:28184 pid:32063 tgid:32061 ppid:23792 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 comedi_open+0xc0/0x5f0 drivers/comedi/comedi_fops.c:2925 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 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+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa3a878f749 RSP: 002b:00007fa3a955e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa3a89e5fa0 RCX: 00007fa3a878f749 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007fa3a8813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa3a89e6038 R14: 00007fa3a89e5fa0 R15: 00007ffff0527cb8 Showing all locks held in the system: 7 locks held by kworker/1:0/24: #0: ffff888140af1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888140af1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900001e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900001e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888027e43198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888027e43198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff8880b873a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #4: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #5: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #6: ffff8880b8739858 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x7eb/0xf90 kernel/workqueue.c:-1 1 lock held by khungtaskd/32: #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5577: #0: ffff888033f500a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 1 lock held by udevd/5860: 2 locks held by syz-executor/21899: #0: ffff8880242fc0e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880242fc0e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880242fc0e0 (&type->s_umount_key#69){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956 1 lock held by syz.2.9734/29768: 1 lock held by syz.7.10183/32063: #0: ffff88802f1f98f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x5f0 drivers/comedi/comedi_fops.c:2925 1 lock held by cmp/7387: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7388 Comm: rm Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:native_set_pte arch/x86/include/asm/pgtable_64.h:65 [inline] RIP: 0010:set_ptes include/linux/pgtable.h:295 [inline] RIP: 0010:set_pte_range+0x577/0x8a0 mm/memory.c:5483 Code: c6 58 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3b 1f 19 00 4d 8b 36 e9 c1 02 00 00 e8 be fe b2 ff 4c 89 6c 24 10 <48> 8b 5c 24 10 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 RSP: 0000:ffffc9000b4af8b0 EFLAGS: 00000287 RAX: 0000000000000003 RBX: ffff88813ff1c980 RCX: 0000000000000001 RDX: 0000000000000005 RSI: ffffffff8d9759c8 RDI: ffff88803403bd00 RBP: ffffea000049dcc0 R08: ffff88801acc543f R09: 1ffff11003598a87 R10: dffffc0000000000 R11: ffffed1003598a88 R12: dffffc0000000000 R13: 0000000012773025 R14: ffff8880506af950 R15: 0000000000000001 FS: 00007fc339debc80(0000) GS:ffff888125e21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc339f2af50 CR3: 000000007ff7e000 CR4: 0000000000350ef0 Call Trace: filemap_map_order0_folio mm/filemap.c:3856 [inline] filemap_map_pages+0xfcd/0x1fd0 mm/filemap.c:3921 do_fault_around mm/memory.c:5713 [inline] do_read_fault mm/memory.c:5746 [inline] do_fault mm/memory.c:5889 [inline] do_pte_missing+0x20b0/0x3330 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fc339f2af50 Code: Unable to access opcode bytes at 0x7fc339f2af26. RSP: 002b:00007ffc226bbba8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00007fc339e874d0 RCX: 00007fc339fa9487 RDX: 0000000000000000 RSI: 00007fc339e803ae RDI: 00007fc339e802e2 RBP: 0000000000000003 R08: 00007fc33a193af8 R09: 0000000000000000 R10: 00007ffc226bb910 R11: 0000000000000246 R12: 00007ffc226bbce8 R13: 00007ffc226bbd08 R14: 00007fc339e874d0 R15: 0000000000000000