rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l P5834/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=20669, q=1392 ncpus=2)
task:kworker/0:3 state:R running task stack:26104 pid:5834 tgid:5834 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x180c/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b 7c 24 48 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 <74> 05 e8 0d 21 b1 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03
RSP: 0018:ffffc90003eaee98 EFLAGS: 00000246
RAX: 1ffff920007d5df4 RBX: ffffffff903e3e01 RCX: 0000000000000001
RDX: ffffc90003eaefa8 RSI: dffffc0000000000 RDI: ffffc90003eaefa0
RBP: dffffc0000000000 R08: ffffc90003eaf1d0 R09: ffffc90003eaefb8
R10: dffffc0000000000 R11: fffff520007d5df9 R12: ffffc90003eaf1d0
R13: ffffc90003eaefb8 R14: ffffc90003eaef68 R15: ffffffff81729de5
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
discard_slab mm/slub.c:2717 [inline]
__put_partials+0x161/0x1c0 mm/slub.c:3186
put_cpu_partial+0x17c/0x250 mm/slub.c:3261
__slab_free+0x2f7/0x400 mm/slub.c:4513
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:385
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4328 [inline]
__kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4340
kmalloc_noprof include/linux/slab.h:909 [inline]
usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75
usb_internal_control_msg drivers/usb/core/message.c:96 [inline]
usb_control_msg+0x118/0x3e0 drivers/usb/core/message.c:154
get_port_status drivers/usb/core/hub.c:605 [inline]
hub_ext_port_status+0x116/0x820 drivers/usb/core/hub.c:622
hub_port_wait_reset drivers/usb/core/hub.c:-1 [inline]
hub_port_reset+0x72e/0x1750 drivers/usb/core/hub.c:3061
hub_port_init+0xfb9/0x2800 drivers/usb/core/hub.c:5024
hub_port_connect drivers/usb/core/hub.c:5464 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
port_event drivers/usb/core/hub.c:5835 [inline]
hub_event+0x2518/0x4a00 drivers/usb/core/hub.c:5917
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:kworker/0:0 state:R running task stack:23640 pid:9 tgid:9 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 cb 97 fe 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900000e7030 EFLAGS: 00000206
RAX: dcd801f34a5b7100 RBX: 0000000000000202 RCX: dcd801f34a5b7100
RDX: 0000000000000006 RSI: ffffffff8db6dd48 RDI: ffffffff8be28300
RBP: ffff88801ca88be0 R08: ffffc900000e75d0 R09: ffffc900000e71b8
R10: dffffc0000000000 R11: fffff5200001ce39 R12: 0000000000000006
R13: 0000000000000006 R14: ffffffff8e13eda0 R15: ffff88801ca88000
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
discard_slab mm/slub.c:2717 [inline]
__put_partials+0x161/0x1c0 mm/slub.c:3186
put_cpu_partial+0x17c/0x250 mm/slub.c:3261
__slab_free+0x2f7/0x400 mm/slub.c:4513
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:385
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
kmalloc_noprof include/linux/slab.h:905 [inline]
usb_control_msg+0x73/0x3e0 drivers/usb/core/message.c:144
get_port_status drivers/usb/core/hub.c:605 [inline]
hub_ext_port_status+0x116/0x820 drivers/usb/core/hub.c:622
usb_hub_port_status drivers/usb/core/hub.c:672 [inline]
port_event drivers/usb/core/hub.c:5728 [inline]
hub_event+0x770/0x4a00 drivers/usb/core/hub.c:5917
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 3687 jiffies! g20669 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6 Comm: kworker/R-kvfre Not tainted 6.16.0-rc1-syzkaller-g19272b37aa4f #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: 0x0 (kvfree_rcu_reclaim)
RIP: 0010:spin_lock include/linux/spinlock.h:351 [inline]
RIP: 0010:usb_hcd_unlink_urb_from_ep+0x27/0x110 drivers/usb/core/hcd.c:1224
Code: 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 89 f3 49 bd 00 00 00 00 00 fc ff df e8 20 98 a0 fa 48 c7 c7 a0 0f de 8e d4 c1 48 04 4c 8d 73 18 4c 89 f7 e8 48 a8 a7 fd 84 c0 74 74 e8
RSP: 0018:ffffc90000a08968 EFLAGS: 00000046
RAX: ffffffff871fc6d0 RBX: ffff888057672800 RCX: ffff88801ca81e00
RDX: 0000000000000100 RSI: ffff888057672800 RDI: ffffffff8ede0fa0
RBP: ffffc90000a08c90 R08: 000000001b5d8341 R09: 000000009c5225ff
R10: 000000000000000c R11: ffffffff81acf990 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88814479f000 R15: ffff888057672800
FS: 0000000000000000(0000) GS:ffff888125d52000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000280b000 CR3: 0000000028196000 CR4: 0000000000350ef0
Call Trace:
dummy_timer+0x846/0x4550 drivers/usb/gadget/udc/dummy_hcd.c:1993
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:kthread_set_per_cpu+0x4/0x1a0 kernel/kthread.c:668
Code: ff e8 50 2c 96 00 eb aa 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 89 f3 49 89 fe 49 bc 00 00 00 00 00
RSP: 0018:ffffc900000b7c38 EFLAGS: 00000246
RAX: ffffffff818c84de RBX: ffff88814042a150 RCX: ffff88801ca81e00
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff88801ca81e00
RBP: 0000000000000001 R08: ffffffff8fa108f7 R09: 1ffffffff1f4211e
R10: dffffc0000000000 R11: fffffbfff1f4211f R12: 1ffff1102808542a
R13: ffff88801a498060 R14: ffff88814042a158 R15: dffffc0000000000
unbind_worker+0x9c/0x190 kernel/workqueue.c:2705
detach_worker kernel/workqueue.c:2717 [inline]
worker_detach_from_pool kernel/workqueue.c:2737 [inline]
rescuer_thread+0x8ef/0xdd0 kernel/workqueue.c:3531
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245