INFO: task syz.6.1366:4907 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1366 state:D stack:0 pid:4907 tgid:4721 ppid:4008 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 device_lock include/linux/device.h:908 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2608 [inline] usbdev_ioctl+0x13f/0x20a0 drivers/usb/core/devio.c:2824 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0x132/0x1b0 fs/ioctl.c:893 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17 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: 0033:0x7f067738eba9 RSP: 002b:00007f0678216038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f06775d6450 RCX: 00007f067738eba9 RDX: 0000200000000980 RSI: 000000004010aeac RDI: 0000000000000006 RBP: 00007f0677411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f06775d64e8 R14: 00007f06775d6450 R15: 00007ffe435eb248 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 064bd8e71db8281f775729d9237f740d6717dea5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 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: 0 Comm: swapper/0 Not tainted syzkaller #0 064bd8e71db8281f775729d9237f740d6717dea5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106 Code: cc cc cc b8 2e 93 67 d4 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 e1 3a 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> c3 cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff87207da0 EFLAGS: 000002c6 RAX: ffff8881f6e00000 RBX: ffffffff87215540 RCX: ffffffff858c70ae RDX: 0000000000000001 RSI: 0000000000000004 RDI: 000000000044879c RBP: ffffffff87207da0 R08: ffff8881f6e39733 R09: 1ffff1103edc72e6 R10: dffffc0000000000 R11: ffffed103edc72e7 R12: 1ffffffff0e42aa8 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff87cb1028 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff510fa4198 CR3: 00000001056be000 CR4: 00000000003526b0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline] default_idle+0x17/0x30 arch/x86/kernel/process.c:754 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:791 default_idle_call+0x3f/0x80 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1a0/0x470 kernel/sched/idle.c:326 cpu_startup_entry+0x48/0x70 kernel/sched/idle.c:424 rest_init+0x10b/0x130 init/main.c:748 start_kernel+0x46a/0x4bb init/main.c:1135 x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x6a/0x7b arch/x86/kernel/head64.c:488 common_startup_64+0x13b/0x157