rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=1004/1/0x4000000000000000 softirq=86937/86938 fqs=0
rcu: (detected by 1, t=10506 jiffies, g=100625, q=393 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5608 Comm: kworker/0:3 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:mark_lock+0x17/0xa20 kernel/locking/lockdep.c:4714
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 56 41 55 49 89 fd 41 54 49 89 f4 53 48 83 e4 f0 <48> 83 ec 70 65 48 8b 1d 15 8d 26 12 48 89 5c 24 68 89 d3 83 fa 08
RSP: 0018:ffffc90000007c00 EFLAGS: 00000086
RAX: 000000000000000c RBX: ffff888037f00c58 RCX: 0000000000000005
RDX: 0000000000000008 RSI: ffff888037f00c58 RDI: ffff888037f00000
RBP: ffffc90000007c30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000001 R12: ffff888037f00c58
R13: ffff888037f00000 R14: 0000000000000005 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff888124372000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f67f6389f9c CR3: 0000000046739000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x4a5/0x2630 kernel/locking/lockdep.c:5191
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166
debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:890
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:1898 [inline]
__hrtimer_run_queues+0x2f0/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 7b 5a 26 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 86 28 f3 0e 0f 82 a4 02 00 00 8b 35 0e 5c f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 5a 26 12 0f 85 ed 02 00 00 48 83 c4
RSP: 0018:ffffc900039fef60 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000003
RDX: 0000000000000000 RSI: ffffffff8defbc27 RDI: ffffffff8c1c3800
RBP: ffffffff8e7e54e0 R08: 0000000056a09c81 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905
__kernfs_new_node+0xd2/0x9f0 fs/kernfs/dir.c:664
kernfs_new_node+0x11b/0x1a0 fs/kernfs/dir.c:748
kernfs_create_dir_ns+0x4c/0x1a0 fs/kernfs/dir.c:1121
sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59
create_dir lib/kobject.c:73 [inline]
kobject_add_internal+0x2c8/0x930 lib/kobject.c:240
kobject_add_varg lib/kobject.c:374 [inline]
kobject_add+0x16a/0x1e0 lib/kobject.c:426
device_add+0x294/0x1950 drivers/base/core.c:3629
usb_create_ep_devs+0x160/0x2b0 drivers/usb/core/endpoint.c:162
usb_new_device.cold+0xcf3/0x115c drivers/usb/core/hub.c:2725
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10506 jiffies! g100625 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 17455 Comm: syz.2.2819 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:write_comp_data+0x2b/0x90 kernel/kcov.c:272
Code: 8b 05 59 40 02 12 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d 30 40 02 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 cc cc cc cc 8b 87 d4 16 00 00 85 c0 74 f1 8b 87 b0 16 00 00 83
RSP: 0018:ffffc9000792fb38 EFLAGS: 00000297
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81fc238d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88802229ca00
RBP: ffff8880b8443320 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed1017088665 R14: 0000000000000001 R15: ffff8880b853c5c0
FS: 00007f8b1d4866c0(0000) GS:ffff888124472000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000061dbb000 CR4: 00000000003526f0
Call Trace:
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0x5ad/0x1700 kernel/smp.c:892
clock_was_set+0x62b/0x870 kernel/time/hrtimer.c:999
do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1603
do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
__do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline]
__x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b1c59cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8b1d486028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f8b1c815fa0 RCX: 00007f8b1c59cdd9
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f8b1c632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b1c816038 R14: 00007f8b1c815fa0 R15: 00007ffed1fb5538