GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29686/1:b..l rcu: (detected by 1, t=10503 jiffies, g=129941, q=2141 ncpus=2) task:syz-executor state:R running task stack:22216 pid:29686 tgid:29686 ppid:29670 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3d0 kernel/locking/lockdep.c:5893 Code: c8 7a 11 00 00 00 00 eb b5 e8 35 f5 0c 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 b5 82 7a 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 1a db 0f 0a cc 48 8d 3d 62 3e 73 RSP: 0018:ffffc900055e7738 EFLAGS: 00000282 RAX: 22c28fc4a4fde500 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000001 RSI: ffffffff8e168b06 RDI: ffffffff8c27c200 RBP: ffff888057304880 R08: ffffffff81d547c6 R09: ffffffff8e75e520 R10: ffffc900055e7858 R11: ffffffff81b0c260 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e75e520 R15: ffff888057303d00 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] is_bpf_text_address+0x28d/0x2b0 kernel/bpf/core.c:750 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5573 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_noprof+0x316/0x760 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] lsm_blob_alloc security/security.c:192 [inline] lsm_sock_alloc security/security.c:4375 [inline] security_sk_alloc+0x52/0x360 security/security.c:4391 sk_prot_alloc+0x101/0x210 net/core/sock.c:2248 sk_alloc+0x3a/0x390 net/core/sock.c:2301 inet_create+0x7a0/0x1000 net/ipv4/af_inet.c:334 __sock_create+0x4b2/0x9d0 net/socket.c:1605 sock_create net/socket.c:1663 [inline] __sys_socket_create net/socket.c:1700 [inline] __sys_socket+0xd6/0x1b0 net/socket.c:1747 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f64dc19e007 RSP: 002b:00007ffceb501ec8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f64dc19e007 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 00007ffceb5025fc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f64dc3e9fc0 R13: 00000000000927c0 R14: 00000000000b698e R15: 00007f64dc3ec180 rcu: rcu_preempt kthread starved for 571 jiffies! g129941 f0x0 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:26760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1117 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:122 [inline] RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:431 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x622/0xbc0 kernel/locking/qspinlock.c:325 Code: 00 41 c6 07 00 43 0f b6 04 26 84 c0 0f 85 7c 01 00 00 c6 01 01 41 bc 00 80 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 28 44 01 06 02 66 c7 84 24 90 00 00 00 00 01 48 8b 4c 24 48 0f b6 RSP: 0018:ffffc90000007520 EFLAGS: 00000286 RAX: dffffc0000000000 RBX: ffffc900000075c0 RCX: 1ffff92000000eb0 RDX: 0000000000000100 RSI: ffffffff8def8008 RDI: ffff8880b863bcc0 RBP: ffffc90000007630 R08: ffffffff9011a4b7 R09: 1ffffffff2023496 R10: dffffc0000000000 R11: fffffbfff2023497 R12: 00000000ffffcf56 R13: 0000000000000000 R14: 1ffff11016713460 R15: ffff8880b863bcd4 FS: 0000000000000000(0000) GS:ffff88812545c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555659aea28 CR3: 000000007e0e4000 CR4: 00000000003526f0 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline] queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x26c/0x2f0 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:341 [inline] __netif_tx_lock include/linux/netdevice.h:4746 [inline] __dev_queue_xmit+0x12de/0x3890 net/core/dev.c:4843 dev_queue_xmit include/linux/netdevice.h:3385 [inline] can_send+0x921/0xd20 net/can/af_can.c:279 can_can_gw_rcv+0xcb0/0xf70 net/can/gw.c:569 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0x126/0x7a0 net/can/af_can.c:602 can_receive+0x2c6/0x440 net/can/af_can.c:674 can_rcv+0x1f9/0x330 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6176 [inline] __netif_receive_skb net/core/dev.c:6289 [inline] process_backlog+0xc66/0x1950 net/core/dev.c:6640 __napi_poll+0xae/0x340 net/core/dev.c:7704 napi_poll net/core/dev.c:7767 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7924 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 blake2s_compress+0xf9/0x1eb0 lib/crypto/x86/blake2s.h:42 blake2s_final+0x116/0x270 lib/crypto/blake2s.c:142 mix_hash drivers/net/wireguard/noise.c:439 [inline] message_ephemeral+0x1b2/0x310 drivers/net/wireguard/noise.c:492 wg_noise_handshake_create_initiation+0x257/0x830 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog