rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9009/1:b..l rcu: (detected by 1, t=10502 jiffies, g=24873, q=896 ncpus=2) task:syz.4.899 state:R running task stack:26984 pid:9009 tgid:9008 ppid:5628 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319 Code: 48 8d 3d a3 cf 8c 04 48 c7 c6 96 65 fa 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 31 c0 83 3d 93 3e 89 04 00 74 1d 83 3d 6a 70 89 04 00 RSP: 0018:ffffc900032cf318 EFLAGS: 00000206 RAX: ffffc900032d0000 RBX: ffffc900032cf3d8 RCX: ffffc900032cf7f0 RDX: ffffffff90d3b901 RSI: 0000000000000000 RDI: ffffc900032cf3d0 RBP: 1ffffffff21a7701 R08: ffffc900032cf7e8 R09: 0000000000000000 R10: ffffc900032cf418 R11: fffff52000659e85 R12: ffffc900032c8000 R13: ffffffff8176a21f R14: ffffc900032cf3c8 R15: ffffc900032cf7e8 rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x1b5d/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 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:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5672 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kvmalloc_node_noprof+0x520/0x890 mm/slub.c:6833 bpf_compute_postorder+0x131/0x970 kernel/bpf/cfg.c:663 bpf_check+0x1648/0x4c30 kernel/bpf/verifier.c:20037 bpf_prog_load+0x1419/0x1a10 kernel/bpf/syscall.c:3082 __sys_bpf+0x618/0x950 kernel/bpf/syscall.c:6274 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline] __se_sys_bpf kernel/bpf/syscall.c:6385 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcde279ce59 RSP: 002b:00007fcde09ee028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fcde2a15fa0 RCX: 00007fcde279ce59 RDX: 0000000000000021 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007fcde2832e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcde2a16038 R14: 00007fcde2a15fa0 R15: 00007ffca580cfb8 rcu: rcu_preempt kthread starved for 5742 jiffies! g24873 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:28520 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: CPU: 1 UID: 0 PID: 5722 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: wg-crypt-wg1 wg_packet_tx_worker RIP: 0010:__in6_dev_get include/net/addrconf.h:348 [inline] RIP: 0010:ip6_ignore_linkdown+0x5f/0x140 include/net/addrconf.h:452 Code: 1b e8 95 71 51 01 89 c5 31 ff 89 c6 e8 6a 91 6f f7 85 ed 74 10 e8 91 ff 2a ff 84 c0 74 0e e8 18 8d 6f f7 eb 20 e8 11 8d 6f f7 19 e8 1a 8d 53 f7 89 c5 31 ff 89 c6 e8 3f 91 6f f7 85 ed 74 44 RSP: 0018:ffffc90000a082d8 EFLAGS: 00000246 RAX: ffffffff8a56690f RBX: ffff888078fcf000 RCX: ffff88802a4f3e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffc90000a08600 R09: ffffc90000a08610 R10: ffffc90000a08460 R11: fffff5200014108e R12: 0000000000000003 R13: ffff8880558310c8 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003ff6 CR3: 000000007c0dc000 CR4: 00000000003526f0 Call Trace: find_match+0x9c/0xb40 net/ipv6/route.c:783 __find_rr_leaf+0x243/0x740 net/ipv6/route.c:872 find_rr_leaf net/ipv6/route.c:893 [inline] rt6_select net/ipv6/route.c:937 [inline] fib6_table_lookup+0x3c6/0xae0 net/ipv6/route.c:2255 ip6_pol_route+0x229/0x14d0 net/ipv6/route.c:2292 pol_lookup_func include/net/ip6_fib.h:669 [inline] fib6_rule_lookup+0x556/0x730 net/ipv6/fib6_rules.c:123 ip6_route_input_lookup net/ipv6/route.c:2363 [inline] ip6_route_input+0x78d/0xb20 net/ipv6/route.c:2666 ip6_rcv_finish+0x141/0x280 net/ipv6/ip6_input.c:117 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x774/0x1860 net/core/dev.c:6670 __napi_poll+0xaa/0x330 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7949 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:preempt_schedule_irq+0x48/0xa0 kernel/sched/core.c:7552 Code: 49 be 00 00 00 00 00 fc ff df eb 09 48 f7 03 10 00 00 00 74 53 bf 01 00 00 00 e8 e3 72 ea f5 e8 8e 19 25 f6 fb bf 01 00 00 00 d3 a2 ff ff 9c 58 fa a9 00 02 00 00 74 05 e8 54 1b 25 f6 bf 01 RSP: 0018:ffffc900047ef918 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff903117f7 R09: 1ffffffff20622fe R10: dffffc0000000000 R11: fffffbfff20622ff R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0xd8/0x130 kernel/softirq.c:457 Code: 8b e8 3c 64 20 0a 65 66 8b 05 5c b1 b2 11 66 85 c0 75 32 bf 01 00 00 00 e8 f5 ee 0b 00 e8 00 94 46 00 fb 65 8b 05 38 b1 b2 11 <85> c0 75 05 e8 3f e0 ab ff 5b 41 5e e9 97 45 23 0a cc 90 0f 0b 90 RSP: 0018:ffffc900047efa30 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000201 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: ffffffff81878ef0 RBP: 0000000000000000 R08: ffffffff903117f7 R09: 1ffffffff20622fe R10: dffffc0000000000 R11: fffffbfff20622ff R12: ffff88802b908b08 R13: dffffc0000000000 R14: ffffffff8679a51b R15: ffff88804fcd1dc0 wg_socket_send_skb_to_peer+0x16b/0x1d0 drivers/net/wireguard/socket.c:183 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline] wg_packet_tx_worker+0x1c8/0x7e0 drivers/net/wireguard/send.c:276 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245