INFO: task syz.3.20:526 blocked for more than 122 seconds. Not tainted 6.12.38-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.20 state:D stack:0 pid:526 tgid:525 ppid:488 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5338 [inline] __schedule+0xdb3/0x17c0 kernel/sched/core.c:6718 __schedule_loop kernel/sched/core.c:6795 [inline] schedule+0xc6/0x240 kernel/sched/core.c:6810 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:6867 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x755/0x10d0 kernel/locking/mutex.c:752 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1040 mutex_lock+0xd9/0xf0 kernel/locking/mutex.c:286 device_lock include/linux/device.h:897 [inline] usbdev_open+0x1d1/0x770 drivers/usb/core/devio.c:1051 chrdev_open+0x4de/0x5f0 fs/char_dev.c:414 do_dentry_open+0x972/0x13f0 fs/open.c:958 vfs_open+0x3f/0x350 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2dd2/0x3700 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1441 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: 0033:0x7fad90b8d4d0 RSP: 002b:00007fad91abbb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fad90b8d4d0 RDX: 0000000000000002 RSI: 00007fad91abbc10 RDI: 00000000ffffff9c RBP: 00007fad91abbc10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 0000000000000000 R14: 00007fad90db5fa0 R15: 00007ffd4a902fa8 INFO: task syz.2.19:528 blocked for more than 123 seconds. Not tainted 6.12.38-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.19 state:D stack:0 pid:528 tgid:527 ppid:486 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5338 [inline] __schedule+0xdb3/0x17c0 kernel/sched/core.c:6718 __schedule_loop kernel/sched/core.c:6795 [inline] schedule+0xc6/0x240 kernel/sched/core.c:6810 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:6867 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x755/0x10d0 kernel/locking/mutex.c:752 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1040 mutex_lock+0xd9/0xf0 kernel/locking/mutex.c:286 device_lock include/linux/device.h:897 [inline] usbdev_open+0x1d1/0x770 drivers/usb/core/devio.c:1051 chrdev_open+0x4de/0x5f0 fs/char_dev.c:414 do_dentry_open+0x972/0x13f0 fs/open.c:958 vfs_open+0x3f/0x350 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2dd2/0x3700 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1441 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: 0033:0x7f807c78d4d0 RSP: 002b:00007f807d5b7b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f807c78d4d0 RDX: 0000000000000002 RSI: 00007f807d5b7c10 RDI: 00000000ffffff9c RBP: 00007f807d5b7c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 0000000000000000 R14: 00007f807c9b5fa0 R15: 00007ffcddd4a908 INFO: task syz.5.17:534 blocked for more than 123 seconds. Not tainted 6.12.38-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.17 state:D stack:0 pid:534 tgid:532 ppid:483 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5338 [inline] __schedule+0xdb3/0x17c0 kernel/sched/core.c:6718 __schedule_loop kernel/sched/core.c:6795 [inline] schedule+0xc6/0x240 kernel/sched/core.c:6810 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:6867 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x755/0x10d0 kernel/locking/mutex.c:752 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1040 mutex_lock+0xd9/0xf0 kernel/locking/mutex.c:286 device_lock include/linux/device.h:897 [inline] usbdev_open+0x1d1/0x770 drivers/usb/core/devio.c:1051 chrdev_open+0x4de/0x5f0 fs/char_dev.c:414 do_dentry_open+0x972/0x13f0 fs/open.c:958 vfs_open+0x3f/0x350 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2dd2/0x3700 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1441 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: 0033:0x7ff779d8d4d0 RSP: 002b:00007ff77ab3ab70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007ff779d8d4d0 RDX: 0000000000000002 RSI: 00007ff77ab3ac10 RDI: 00000000ffffff9c RBP: 00007ff77ab3ac10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 0000000000000000 R14: 00007ff779fb5fa0 R15: 00007ffed259b4a8 INFO: task syz.4.18:535 blocked for more than 124 seconds. Not tainted 6.12.38-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.18 state:D stack:0 pid:535 tgid:533 ppid:485 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5338 [inline] __schedule+0xdb3/0x17c0 kernel/sched/core.c:6718 __schedule_loop kernel/sched/core.c:6795 [inline] schedule+0xc6/0x240 kernel/sched/core.c:6810 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:6867 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x755/0x10d0 kernel/locking/mutex.c:752 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1040 mutex_lock+0xd9/0xf0 kernel/locking/mutex.c:286 device_lock include/linux/device.h:897 [inline] usbdev_open+0x1d1/0x770 drivers/usb/core/devio.c:1051 chrdev_open+0x4de/0x5f0 fs/char_dev.c:414 do_dentry_open+0x972/0x13f0 fs/open.c:958 vfs_open+0x3f/0x350 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2dd2/0x3700 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1441 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: 0033:0x7f500998d4d0 RSP: 002b:00007f500a829b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f500998d4d0 RDX: 0000000000000002 RSI: 00007f500a829c10 RDI: 00000000ffffff9c RBP: 00007f500a829c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 0000000000000000 R14: 00007f5009bb5fa0 R15: 00007ffde9c29ce8 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.38-syzkaller #0 a3dd4110fbe1f45edcb32016e70769f071cb81d4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:223 [inline] watchdog+0xbd4/0xc20 kernel/hung_task.c:379 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.38-syzkaller #0 a3dd4110fbe1f45edcb32016e70769f071cb81d4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106 Code: cc cc cc b8 da 93 0a 97 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 66 4c 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 d3 f3 05 00 cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7e00 EFLAGS: 000002c2 RAX: ffff8881f6f00000 RBX: ffff888103659140 RCX: ffffffff853ae9fe RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000d8362c RBP: ffffc900001a7e00 R08: ffff8881f6f39633 R09: 1ffff1103ede72c6 R10: dffffc0000000000 R11: ffffed103ede72c7 R12: 1ffff110206cb228 R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff876329a8 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555594134a8 CR3: 000000012c7e2000 CR4: 00000000003526b0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline] default_idle+0x17/0x30 arch/x86/kernel/process.c:753 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:790 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 start_secondary+0x12e/0x140 arch/x86/kernel/smpboot.c:314 common_startup_64+0x13b/0x157