INFO: task syz.2.19:419 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:0     pid:419   tgid:418   ppid:378    flags:0x00004004
Call Trace:
 <TASK>
 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_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: 0033:0x7fd85298d710
RSP: 002b:00007fd853814b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd85298d710
RDX: 0000000000000002 RSI: 00007fd853814c10 RDI: 00000000ffffff9c
RBP: 00007fd853814c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007fd852be6038 R14: 00007fd852be5fa0 R15: 00007ffd84830158
 </TASK>
INFO: task syz.0.17:421 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:0     pid:421   tgid:420   ppid:377    flags:0x00000004
Call Trace:
 <TASK>
 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_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: 0033:0x7f87ff18d710
RSP: 002b:00007f87fff51b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f87ff18d710
RDX: 0000000000000002 RSI: 00007f87fff51c10 RDI: 00000000ffffff9c
RBP: 00007f87fff51c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f87ff3e6038 R14: 00007f87ff3e5fa0 R15: 00007ffcaea3a368
 </TASK>
INFO: task syz.3.20:425 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20        state:D stack:0     pid:425   tgid:424   ppid:380    flags:0x00000004
Call Trace:
 <TASK>
 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_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: 0033:0x7ff39ed8d710
RSP: 002b:00007ff39fb67b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007ff39ed8d710
RDX: 0000000000000002 RSI: 00007ff39fb67c10 RDI: 00000000ffffff9c
RBP: 00007ff39fb67c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007ff39efe6038 R14: 00007ff39efe5fa0 R15: 00007ffeb6c2da78
 </TASK>
INFO: task syz.5.18:429 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.18        state:D stack:0     pid:429   tgid:428   ppid:375    flags:0x00000004
Call Trace:
 <TASK>
 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_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: 0033:0x7f39d1b8d710
RSP: 002b:00007f39d2a3db70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f39d1b8d710
RDX: 0000000000000002 RSI: 00007f39d2a3dc10 RDI: 00000000ffffff9c
RBP: 00007f39d2a3dc10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f39d1de6038 R14: 00007f39d1de5fa0 R15: 00007ffde7337668
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 68071847e78a8b5e73ab1b858b320f4e6b4f981b
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __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+0x2ca/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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 68071847e78a8b5e73ab1b858b320f4e6b4f981b
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__list_del_entry_valid_or_report+0x37/0x140 lib/list_debug.c:50
Code: 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 0d a2 2d ff 4c 8b 7b 08 <48> 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f3 a1 2d ff
RSP: 0018:ffffc900002307f0 EFLAGS: 00000046
RAX: 1ffff110206ca281 RBX: ffff888103651400 RCX: 1ffff920000460f0
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff888103651408
RBP: ffffc90000230810 R08: ffff888102e45a07 R09: 1ffff110205c8b40
R10: dffffc0000000000 R11: ffffed10205c8b41 R12: dffffc0000000000
R13: ffff888103651400 R14: ffff8881f6e506b0 R15: ffff88810ae4a700
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558e65a4a8 CR3: 000000010bb34000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_move include/linux/list.h:298 [inline]
 detach_tasks kernel/sched/fair.c:9925 [inline]
 sched_balance_rq+0x31bc/0x5060 kernel/sched/fair.c:12068
 sched_balance_domains+0x4b4/0xa10 kernel/sched/fair.c:12500
 _nohz_idle_balance+0x3e3/0x5a0 kernel/sched/fair.c:12951
 nohz_idle_balance kernel/sched/fair.c:12994 [inline]
 sched_balance_softirq+0x8a/0x170 kernel/sched/fair.c:13229
 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
 __do_softirq kernel/softirq.c:659 [inline]
 invoke_softirq kernel/softirq.c:476 [inline]
 __irq_exit_rcu+0x48/0xc0 kernel/softirq.c:708
 irq_exit_rcu+0xd/0x30 kernel/softirq.c:720
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0x7f/0x90 arch/x86/kernel/smp.c:266
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1f/0x30 arch/x86/include/asm/idtentry.h:709
RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106
Code: cc cc cc b8 94 ba c0 ff 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 32 3a 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 d3 54 02 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: ffff88810366b900 RCX: ffffffff858d20be
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 000000000093e2b4
RBP: ffffc900001a7e00 R08: ffff8881f6f39733 R09: 1ffff1103ede72e6
R10: dffffc0000000000 R11: ffffed103ede72e7 R12: 1ffff110206cd720
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff87cb1da8
 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
 start_secondary+0x12e/0x140 arch/x86/kernel/smpboot.c:314
 common_startup_64+0x13b/0x157
 </TASK>