rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6773/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=14249, q=887 ncpus=2)
task:kworker/1:6 state:R running task stack:24024 pid:6773 tgid:6773 ppid:2 task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5401 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6790
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7113
irqentry_exit+0x36/0x90 kernel/entry/common.c:307
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5896
Code: 0f c1 05 78 58 38 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 8d 16 38 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc900038374f0 EFLAGS: 00000206
RAX: 7a4a895007e14c00 RBX: ffffffff8e5c4e80 RCX: ffffc900038374fc
RDX: 0000000000000005 RSI: ffffffff8de0d05d RDI: ffffffff8c158f60
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff822e99dc
R13: 0000000000000206 R14: ffff88807c972440 R15: 0000000000000006
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
__page_table_check_zero+0x341/0x5d0 mm/page_table_check.c:145
page_table_check_free include/linux/page_table_check.h:43 [inline]
free_pages_prepare mm/page_alloc.c:1249 [inline]
__free_frozen_pages+0x7df/0x1180 mm/page_alloc.c:2706
discard_slab mm/slub.c:2717 [inline]
__put_partials+0x16d/0x1c0 mm/slub.c:3186
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/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:4148 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
__kmalloc_cache_noprof+0x1f1/0x3e0 mm/slub.c:4354
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
kobject_uevent_env+0x265/0x1870 lib/kobject_uevent.c:540
device_del+0x623/0x9f0 drivers/base/core.c:3899
usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418
usb_disconnect+0x2e1/0x9c0 drivers/usb/core/hub.c:2344
hub_port_connect drivers/usb/core/hub.c:5406 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
port_event drivers/usb/core/hub.c:5866 [inline]
hub_event+0x1c57/0x4fa0 drivers/usb/core/hub.c:5948
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 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 1365 jiffies! g14249 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5401 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6790
__schedule_loop kernel/sched/core.c:6868 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6883
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc5-syzkaller-00038-g733923397fd9 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:68
Code: e8 62 95 a3 03 e9 c8 fa ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000a07fa0 EFLAGS: 00000202
RAX: ffffffff8b8817df RBX: 0000000000000001 RCX: ffffc90000198000
RDX: ffffc90000197d01 RSI: ffffc90000197d48 RDI: ffffc90000197dc8
RBP: ffffc90000a08060 R08: ffffffff9138710c R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000014 R12: ffffc90000a08068
R13: ffffc90000a08018 R14: ffffc90000197d48 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124816000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000034000 CR3: 000000006a707000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
deref_stack_regs arch/x86/kernel/unwind_orc.c:421 [inline]
unwind_next_frame+0xcd6/0x20a0 arch/x86/kernel/unwind_orc.c:596
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:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4148 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4249
kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:579
__alloc_skb+0x166/0x380 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1336 [inline]
synproxy_send_client_synack+0x1af/0x8f0 net/netfilter/nf_synproxy_core.c:460
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e9/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:272
NF_HOOK include/linux/netfilter.h:315 [inline]
ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:469 [inline]
ip_rcv_finish net/ipv4/ip_input.c:448 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:568
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5977
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6090
process_backlog+0x442/0x15e0 net/core/dev.c:6442
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7414
napi_poll net/core/dev.c:7478 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605
handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0x109/0x170 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+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: fb 6b 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 03 e9 21 00 fb f4 7c fb 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2
RAX: 0000000001750023 RBX: 0000000000000001 RCX: ffffffff8b882c79
RDX: 0000000000000000 RSI: ffffffff8de3251e RDI: ffffffff8c158f60
RBP: ffffed1003c5c488 R08: 0000000000000001 R09: ffffed10170a6645
R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801e2e2440 R14: ffffffff90a97f50 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:749
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
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148