INFO: task syz.0.120:6243 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.120 state:D stack:28264 pid:6243 tgid:6240 ppid:5857 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 bdev_open+0xe0/0xcc0 block/bdev.c:945 blkdev_open+0x46c/0x610 block/fops.c:694 do_dentry_open+0x9b1/0x1350 fs/open.c:965 vfs_open+0x3b/0x350 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ef1/0x3840 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: 0033:0x7f0a96f9d510 RSP: 002b:00007f0a951fdb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000041 RCX: 00007f0a96f9d510 RDX: 0000000000000041 RSI: 00007f0a951fdc10 RDI: 00000000ffffff9c RBP: 00007f0a951fdc10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f0a971e6038 R14: 00007f0a971e5fa0 R15: 00007ffdae80f6c8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:7/1353: #0: ffff888147295938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888147295938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005437bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005437bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 2 locks held by kworker/u8:8/1401: 2 locks held by getty/5597: #0: ffff88823bf320a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 10 locks held by syz-executor/5844: 1 lock held by udevd/5983: #0: ffff888024dca4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945 6 locks held by kworker/0:7/6030: #0: ffff888019899138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019899138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005687bc0 (serio_event_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005687bc0 (serio_event_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8e737198 (serio_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] #2: ffffffff8e737198 (serio_mutex){+.+.}-{4:4}, at: serio_handle_event+0x2f/0x8c0 drivers/input/serio/serio.c:189 #3: ffff88805cc07308 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff88805cc07308 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff88805cc07208 (&serio->drv_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] #4: ffff88805cc07208 (&serio->drv_mutex){+.+.}-{4:4}, at: serio_connect_driver drivers/input/serio/serio.c:41 [inline] #4: ffff88805cc07208 (&serio->drv_mutex){+.+.}-{4:4}, at: serio_driver_probe+0x55/0xd0 drivers/input/serio/serio.c:747 #5: ffff888038672060 (&ps2dev->cmd_mutex){+.+.}-{4:4}, at: ps2_begin_command drivers/input/serio/libps2.c:131 [inline] #5: ffff888038672060 (&ps2dev->cmd_mutex){+.+.}-{4:4}, at: ps2_command+0x70/0xe0 drivers/input/serio/libps2.c:407 1 lock held by syz.0.120/6243: #0: ffff888024dca4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945 1 lock held by syz.1.1820/10168: #0: ffffffff8e737198 (serio_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] #0: ffffffff8e737198 (serio_mutex){+.+.}-{4:4}, at: serio_unregister_port+0x2f/0x190 drivers/input/serio/serio.c:676 1 lock held by syz.2.1826/10189: #0: ffff8880b883aad8 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 4 locks held by syz.5.1828/10194: 4 locks held by syz.4.1827/10195: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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+0x439/0x7d0 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: 10195 Comm: syz.4.1827 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x45/0xa0 kernel/kcov.c:294 Code: e0 00 00 ff 00 ba 00 01 00 00 23 91 0c 0b 00 00 41 89 d1 45 09 c1 74 12 45 85 c0 75 5b 85 d2 74 57 83 b9 d4 15 00 00 00 74 4e <8b> 91 b0 15 00 00 83 fa 03 75 43 48 8b 91 b8 15 00 00 44 8b 89 b4 RSP: 0018:ffffc90003b9f368 EFLAGS: 00000246 RAX: ffffffff822463d6 RBX: 000000000004b31d RCX: ffff888024e40000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff88801c0ff960 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100381ff2c R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: ffff88801c0ff958 FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7cdae54660 CR3: 0000000060db2000 CR4: 00000000003526f0 Call Trace: page_table_check_clear+0x406/0x700 mm/page_table_check.c:78 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:725 [inline] zap_present_folio_ptes mm/memory.c:1499 [inline] zap_present_ptes mm/memory.c:1581 [inline] do_zap_pte_range mm/memory.c:1682 [inline] zap_pte_range mm/memory.c:1726 [inline] zap_pmd_range mm/memory.c:1818 [inline] zap_pud_range mm/memory.c:1847 [inline] zap_p4d_range mm/memory.c:1868 [inline] unmap_page_range+0x2ec0/0x3c10 mm/memory.c:1889 unmap_single_vma mm/memory.c:1932 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1976 exit_mmap+0x248/0xb50 mm/mmap.c:1280 __mmput+0xcb/0x3d0 kernel/fork.c:1129 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efdbb7eeba9 Code: Unable to access opcode bytes at 0x7efdbb7eeb7f. RSP: 002b:00007efdb9a4e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007efdbba35fa8 RCX: 00007efdbb7eeba9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007efdbba35fa8 RBP: 00007efdbba35fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efdbba36038 R14: 00007ffef9cdb050 R15: 00007ffef9cdb138