INFO: task udevd:4029 blocked for more than 122 seconds. Not tainted 6.12.23-syzkaller-g6c1c18fcb8b7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:0 pid:4029 tgid:4029 ppid:109 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5924 [inline] __schedule+0x145b/0x1f10 kernel/sched/core.c:7750 __schedule_loop kernel/sched/core.c:7831 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7846 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270 device_lock include/linux/device.h:1025 [inline] uevent_show+0x194/0x400 drivers/base/core.c:2730 dev_attr_show+0x69/0xe0 drivers/base/core.c:2424 sysfs_kf_seq_show+0x289/0x3a0 fs/sysfs/file.c:59 kernfs_seq_show+0x12e/0x180 fs/kernfs/file.c:205 seq_read_iter+0x50d/0xfe0 fs/seq_file.c:230 kernfs_fop_read_iter+0x149/0x520 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x53d/0xb60 fs/read_write.c:570 ksys_read+0x141/0x250 fs/read_write.c:713 __do_sys_read fs/read_write.c:723 [inline] __se_sys_read fs/read_write.c:721 [inline] __x64_sys_read+0x7f/0x90 fs/read_write.c:721 x64_sys_call+0x2638/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f19c5ca7407 RSP: 002b:00007fff0f33c830 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f19c6377880 RCX: 00007f19c5ca7407 RDX: 0000000000001000 RSI: 000055ad10e93f90 RDI: 0000000000000008 RBP: 00007f19c5defff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f19c5defea0 R14: 0000000000000000 R15: 000055ad10eac530 INFO: task syz.5.2235:6829 blocked for more than 123 seconds. Not tainted 6.12.23-syzkaller-g6c1c18fcb8b7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2235 state:D stack:0 pid:6829 tgid:6828 ppid:6571 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5924 [inline] __schedule+0x145b/0x1f10 kernel/sched/core.c:7750 __schedule_loop kernel/sched/core.c:7831 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7846 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270 device_lock include/linux/device.h:1025 [inline] usbdev_open+0x171/0x840 drivers/usb/core/devio.c:1051 chrdev_open+0x4db/0x5f0 fs/char_dev.c:414 do_dentry_open+0x978/0x1510 fs/open.c:960 vfs_open+0x86/0x230 fs/open.c:1090 do_open fs/namei.c:3774 [inline] path_openat+0x2b6c/0x34b0 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1438 do_sys_open fs/open.c:1453 [inline] __do_sys_openat fs/open.c:1469 [inline] __se_sys_openat fs/open.c:1464 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1464 x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fab8878d290 RSP: 002b:00007fab89596b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000001a1301 RCX: 00007fab8878d290 RDX: 00000000001a1301 RSI: 00007fab89596c10 RDI: 00000000ffffff9c RBP: 00007fab89596c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 0000000000000000 R14: 00007fab889b5fa0 R15: 00007ffda3304738 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.23-syzkaller-g6c1c18fcb8b7 #0 ba78288b1e32eb9f88d3f8d8da6b79a037cd8362 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:229 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:385 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9081 Comm: syz.4.2983 Not tainted 6.12.23-syzkaller-g6c1c18fcb8b7 #0 ba78288b1e32eb9f88d3f8d8da6b79a037cd8362 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:unwind_next_frame+0x5a3/0x750 arch/x86/kernel/unwind_frame.c:370 Code: 06 00 00 48 ba 00 00 00 00 00 fc ff df 48 8b 45 90 0f b6 04 10 84 c0 0f 85 bd 00 00 00 c7 03 00 00 00 00 31 c0 48 83 c4 48 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc c6 05 e3 79 7f 06 01 RSP: 0018:ffffc90009e4f418 EFLAGS: 00000292 RAX: 0000000009e4f401 RBX: ffffc90009e4f500 RCX: 0000000009e4f401 RDX: ffffc90009e4ff20 RSI: 1ffff920013c9e8a RDI: ffffc90009e4f4a0 RBP: ffffc90009e4f438 R08: ffffc90009e4f510 R09: ffffc90009e4f508 R10: 000000000000000b R11: ffffffff8173e5d0 R12: 0000000000000000 R13: 1ffff920013c9e94 R14: ffffc90009e4f4a0 R15: ffffc90009e4fef8 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564fcc10cb98 CR3: 0000000116dd4000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x139/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122 save_stack+0xf8/0x1f0 mm/page_owner.c:174 __reset_page_owner+0x79/0x450 mm/page_owner.c:315 reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1319 [inline] free_unref_page+0xa17/0xcf0 mm/page_alloc.c:2806 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5271 vfree+0x3bf/0x580 mm/vmalloc.c:3388 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x2c/0x70 kernel/kcov.c:535 __fput+0x1fb/0xa00 fs/file_table.c:431 ____fput+0x20/0x30 fs/file_table.c:459 task_work_run+0x1e0/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9b4/0x2630 kernel/exit.c:944 do_group_exit+0x22a/0x300 kernel/exit.c:1094 get_signal+0x139d/0x14f0 kernel/signal.c:2934 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f6a7bdc11e5 Code: Unable to access opcode bytes at 0x7f6a7bdc11bb. RSP: 002b:00007f6a7cc9cf80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f6a7bfb5fa0 RCX: 00007f6a7bdc11e5 RDX: 00007f6a7cc9cfc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6a7be10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6a7bfb5fa0 R15: 00007ffe5a39ccf8