rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5923/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=9065, q=840 ncpus=2)
task:kworker/0:7 state:R running task stack:26088 pid:5923 tgid:5923 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:867 [inline]
RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0xcc/0x20b0 arch/x86/kernel/unwind_orc.c:495
Code: 45 38 48 89 44 24 10 e8 22 47 36 00 31 d2 45 31 c9 45 31 c0 48 8d 05 00 00 00 00 50 b9 02 00 00 00 31 f6 48 c7 c7 20 96 3c 8e 8f 44 2d 00 e8 da 50 0b 0a 5a 85 c0 0f 85 a2 09 00 00 48 b8 00
RSP: 0018:ffffc9000468f028 EFLAGS: 00000246
RAX: ffffffff816cb66d RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e3c9620
RBP: ffffc9000468f0e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000061627 R12: ffffffff81a960d0
R13: ffffc9000468f0a0 R14: 0000000000000000 R15: ffff88802b150000
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6668 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6876
rh_call_control drivers/usb/core/hcd.c:705 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:821 [inline]
usb_hcd_submit_urb+0xae2/0x1cf0 drivers/usb/core/hcd.c:1542
usb_submit_urb+0x899/0x1970 drivers/usb/core/urb.c:587
usb_start_wait_urb+0x104/0x4e0 drivers/usb/core/message.c:59
usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
usb_control_msg+0x326/0x4a0 drivers/usb/core/message.c:154
usb_clear_port_feature drivers/usb/core/hub.c:456 [inline]
hub_port_reset+0x74a/0x1d50 drivers/usb/core/hub.c:3107
hub_port_init+0x716/0x3a90 drivers/usb/core/hub.c:5056
hub_port_connect drivers/usb/core/hub.c:5496 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2ee7/0x52f0 drivers/usb/core/hub.c:5953
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: rcu_preempt kthread starved for 10542 jiffies! g9065 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:28920 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6189 Comm: syz.3.64 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 2a 0e 1f f6 48 89 df e8 e2 60 1f f6 e8 7d 22 4c f6 fb bf 01 00 00 00 f2 63 0f f6 65 8b 05 9b c9 37 08 85 c0 74 06 5b e9 01 4d 00 00
RSP: 0018:ffffc90005ef7cc8 EFLAGS: 00000206
RAX: 0000000004f146c5 RBX: ffff8880286b5340 RCX: ffffffff81c7080f
RDX: 0000000000000000 RSI: ffffffff8dacde18 RDI: 0000000000000001
RBP: ffff8880795cae28 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9088b3d7 R11: ffff8880795caff0 R12: ffff8880795ca4c0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fdafb4186c0(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffe70 CR3: 000000007584b000 CR4: 00000000003526f0
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
__set_current_blocked kernel/signal.c:3222 [inline]
set_current_blocked kernel/signal.c:3206 [inline]
signal_delivered kernel/signal.c:3070 [inline]
signal_setup_done+0x2b1/0x570 kernel/signal.c:3082
handle_signal arch/x86/kernel/signal.c:312 [inline]
arch_do_signal_or_restart+0x4b4/0x7e0 arch/x86/kernel/signal.c:339
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdafa5b7e80
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 8a 54 08 00 e8 05 8f f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007fdafb4173f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fdafa7e5fa8 RCX: 00007fdafa58f749
RDX: 00007fdafb417400 RSI: 00007fdafb417530 RDI: 0000000000000021
RBP: 00007fdafa7e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdafa7e6038 R14: 00007ffcf7253990 R15: 00007ffcf7253a78