rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P949/1:b..l P12611/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=36477, q=1189215 ncpus=2)
task:syz.4.2140 state:R running task stack:27608 pid:12611 tgid:12610 ppid:5809 task_flags:0x40054c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6947
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1761 [inline]
zap_pmd_range mm/memory.c:1823 [inline]
zap_pud_range mm/memory.c:1852 [inline]
zap_p4d_range mm/memory.c:1873 [inline]
unmap_page_range+0xf08/0x4390 mm/memory.c:1894
unmap_single_vma+0x194/0x2a0 mm/memory.c:1940
unmap_vmas+0x22c/0x490 mm/memory.c:1984
exit_mmap+0x1b9/0xb90 mm/mmap.c:1284
__mmput+0x12a/0x410 kernel/fork.c:1379
mmput+0x62/0x70 kernel/fork.c:1401
exit_mm kernel/exit.c:589 [inline]
do_exit+0x9d1/0x2c30 kernel/exit.c:940
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb67118e56b
RSP: 002b:00007fb671f9bf10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007fb67118e56b
RDX: 00007fb671f9cfe0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007fb671f9cfe0 R08: 0000000000000080 R09: 00007fb671f9bfd8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000000000000012 R15: 00007fb67121ba1e
task:kworker/1:2 state:R running task stack:22200 pid:949 tgid:949 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090
irqentry_exit+0x36/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5943
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 6c 87 37 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb
RSP: 0018:ffffc900036e7330 EFLAGS: 00000296
RAX: 0000000000000046 RBX: ffff888026c68be0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dbbbc2f RDI: ffffffff8bf48260
RBP: ffffffff8e3bf5c0 R08: 0000000000000007 R09: 000000000007ffff
R10: 000000000000000b R11: 0000000000000000 R12: ffff888026c68000
R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000006
lookup_page_ext+0xe8/0x190 mm/page_ext.c:254
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
__update_page_owner_free_handle.constprop.0+0x91/0x470 mm/page_owner.c:272
__reset_page_owner+0x93/0x1a0 mm/page_owner.c:309
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1262 [inline]
__free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725
discard_slab mm/slub.c:2716 [inline]
__put_partials+0x16d/0x1c0 mm/slub.c:3185
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4147 [inline]
slab_alloc_node mm/slub.c:4196 [inline]
__kmalloc_cache_noprof+0x1f1/0x3e0 mm/slub.c:4353
kmalloc_noprof include/linux/slab.h:905 [inline]
dummy_urb_enqueue+0xa3/0x920 drivers/usb/gadget/udc/dummy_hcd.c:1273
usb_hcd_submit_urb+0x258/0x1c60 drivers/usb/core/hcd.c:1533
usb_submit_urb+0x87c/0x1730 drivers/usb/core/urb.c:581
usb_start_wait_urb+0x104/0x4b0 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_get_descriptor+0xbb/0x1b0 drivers/usb/core/message.c:794
usb_get_device_descriptor+0x71/0xe0 drivers/usb/core/message.c:1065
hub_port_init+0x14f6/0x3a70 drivers/usb/core/hub.c:5140
hub_port_connect drivers/usb/core/hub.c:5460 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x2c67/0x4fa0 drivers/usb/core/hub.c:5913
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 9196 jiffies! g36477 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27608 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81
Code: 15 62 02 c3 cc cc cc cc 0f 1f 00 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 73 1a 1d 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007e10 EFLAGS: 000002c6
RAX: 00000000038ae629 RBX: 0000000000000000 RCX: ffffffff8b6cd419
RDX: 0000000000000000 RSI: ffffffff8dbe121f RDI: ffffffff8bf48260
RBP: fffffbfff1c12ee8 R08: 0000000000000001 R09: ffffed10170865bd
R10: ffff8880b8432deb R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8e097740 R14: ffffffff90850510 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249df000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff141ff6080 CR3: 000000005145b000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:748
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
rest_init+0x16b/0x2b0 init/main.c:743
start_kernel+0x3e9/0x4d0 init/main.c:1099
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:513
x86_64_start_kernel+0xb0/0xc0 arch/x86/kernel/head64.c:494
common_startup_64+0x13e/0x148