rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6610/2:b..l P6060/3:b..l P6568/1:b..l P30/3:b..l
rcu: (detected by 1, t=10502 jiffies, g=15141, q=778 ncpus=2)
task:ksoftirqd/1 state:D stack:21368 pid:30 tgid:30 ppid:2 task_flags:0x4208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7024
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x158/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
rh_queue_status drivers/usb/core/hcd.c:791 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:819 [inline]
usb_hcd_submit_urb+0x261/0x1b60 drivers/usb/core/hcd.c:1542
hub_resubmit_irq_urb+0x80/0x160 drivers/usb/core/hub.c:690
__usb_hcd_giveback_urb+0x3b4/0x5e0 drivers/usb/core/hcd.c:1661
usb_giveback_urb_bh+0x296/0x420 drivers/usb/core/hcd.c:1695
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
bh_worker+0x2ca/0x630 kernel/workqueue.c:3611
tasklet_hi_action+0xf/0x70 kernel/softirq.c:958
handle_softirqs+0x226/0x6d0 kernel/softirq.c:622
run_ksoftirqd+0xac/0x210 kernel/softirq.c:1063
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:kworker/1:11 state:R running task stack:22408 pid:6568 tgid:6568 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7140
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3b0 kernel/locking/lockdep.c:5879
rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
spin_unlock_irqrestore include/linux/spinlock_rt.h:122 [inline]
usb_hcd_poll_rh_status+0x406/0x620 drivers/usb/core/hcd.c:762
dummy_hub_control+0xffb/0x1a30 drivers/usb/gadget/udc/dummy_hcd.c:2371
rh_call_control drivers/usb/core/hcd.c:656 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:821 [inline]
usb_hcd_submit_urb+0xdbe/0x1b60 drivers/usb/core/hcd.c:1542
usb_start_wait_urb+0x115/0x4f0 drivers/usb/core/message.c:59
usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
usb_control_msg+0x232/0x3e0 drivers/usb/core/message.c:154
get_port_status drivers/usb/core/hub.c:607 [inline]
hub_ext_port_status+0x116/0x820 drivers/usb/core/hub.c:624
usb_hub_port_status drivers/usb/core/hub.c:674 [inline]
port_event drivers/usb/core/hub.c:5761 [inline]
hub_event+0x778/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:syz-executor state:R running task stack:18616 pid:6060 tgid:6060 ppid:1 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 b4 88 14 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000c0372b0 EFLAGS: 00000206
RAX: 74a338e04295be00 RBX: 0000000000000000 RCX: 74a338e04295be00
RDX: 00000000fa4225d5 RSI: ffffffff8cfdf958 RDI: ffffffff8b3f4de0
RBP: ffffffff8229b224 R08: ffffffff8229b224 R09: ffffffff8d5ae880
R10: dffffc0000000000 R11: fffff94000305d81 R12: 0000000000000002
R13: ffffffff8d5ae880 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
page_table_check_clear+0x164/0x5f0 mm/page_table_check.c:77
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
zap_present_folio_ptes mm/memory.c:1626 [inline]
zap_present_ptes mm/memory.c:1708 [inline]
do_zap_pte_range mm/memory.c:1810 [inline]
zap_pte_range mm/memory.c:1854 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x2f39/0x3ce0 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0xcb/0x3d0 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3af33be15c
RSP: 002b:00007fff7131fdd0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007f3af33be15c
RDX: 0000000000000030 RSI: 00007fff7131fe90 RDI: 00000000000000f9
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fff7131fb47
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3af35e4280 R14: 0000000000000003 R15: 00007fff7131fe90
task:syz.0.169 state:R running task stack:24920 pid:6610 tgid:6610 ppid:5799 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
rcu_read_unlock_sched include/linux/rcupdate.h:981 [inline]
pfn_valid+0x402/0x490 include/linux/mmzone.h:2193
page_table_check_clear+0x21/0x5f0 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
zap_present_folio_ptes mm/memory.c:1626 [inline]
zap_present_ptes mm/memory.c:1708 [inline]
do_zap_pte_range mm/memory.c:1810 [inline]
zap_pte_range mm/memory.c:1854 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x2f39/0x3ce0 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0xcb/0x3d0 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff78a3d2005
RSP: 002b:00007ffdd7e38850 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 00007ff78a5f5fa0 RCX: 00007ff78a3d2005
RDX: 00007ffdd7e38890 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ff78a5f7da0 R08: 0000000000000000 R09: 3fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000002c80c
R13: 00007ff78a5f6090 R14: ffffffffffffffff R15: 00007ffdd7e389d0
rcu: rcu_preempt kthread starved for 782 jiffies! g15141 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:26136 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 03 ca 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 26 15 00 f3 0f 1e fa fb f4 d8 c9 03 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900001d7de0 EFLAGS: 000002c2
RAX: a48b3a43442f2000 RBX: ffffffff819663da RCX: a48b3a43442f2000
RDX: 0000000000000001 RSI: ffffffff8ce09b53 RDI: ffffffff8b3f4de0
RBP: ffffc900001d7f10 R08: ffff8880b8933c5b R09: 1ffff1101712678b
R10: dffffc0000000000 R11: ffffed101712678c R12: ffffffff8edb0c70
R13: 1ffff11003757b58 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126e06000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 000000005dc5c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147