rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=8ff4/1/0x4000000000000000 softirq=16991/17011 fqs=5 rcu: (detected by 0, t=10502 jiffies, g=11417, q=1404 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6195 Comm: kworker/u8:9 Not tainted 6.13.0-syzkaller-04057-g15a901361ec3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:230 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4852 [inline] RIP: 0010:__lock_acquire+0x4b4/0x2100 kernel/locking/lockdep.c:5178 Code: 13 00 00 44 89 3b 44 89 f3 48 89 d8 48 c1 e8 06 48 8d 3c c5 40 58 2f 94 be 08 00 00 00 e8 14 17 8b 00 48 0f a3 1d 1c 6b b4 12 <73> 27 48 69 c3 c8 00 00 00 48 8d 98 00 d7 c6 93 48 ba 00 00 00 00 RSP: 0018:ffffc90000a17270 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000021 RCX: ffffffff817aed1c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff942f5840 RBP: 00000000000a6021 R08: ffffffff942f5847 R09: 1ffffffff285eb08 R10: dffffc0000000000 R11: fffffbfff285eb09 R12: ffff8880274028c4 R13: 000000000000001e R14: 0000000000000021 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c26df83 CR3: 000000005a4ee000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1738 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1802 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1864 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_rdp_cpu_online kernel/rcu/tree.c:3920 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x87/0x120 kernel/rcu/tree.c:3961 Code: 3c 30 00 74 08 48 89 df e8 e6 73 80 00 48 8b 03 48 8d 98 80 f8 03 00 48 8d b8 a0 f8 03 00 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <74> 05 e8 c2 73 80 00 4c 8b 7b 20 48 83 c3 18 48 89 d8 48 c1 e8 03 RSP: 0018:ffffc90000a17910 EFLAGS: 00000246 RAX: 1ffff110170e7f14 RBX: ffff8880b873f880 RCX: 0000000080000101 RDX: ffff888027401e00 RSI: ffffffff8c601480 RDI: ffff8880b873f8a0 RBP: ffffc90000a17ab8 R08: ffffffff8a76e23c R09: ffffc90000a17bf0 R10: ffffc90000a17be0 R11: fffff52000142f4a R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: dffffc0000000000 rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 __find_rr_leaf+0x395/0x8e0 net/ipv6/route.c:800 find_rr_leaf net/ipv6/route.c:856 [inline] rt6_select net/ipv6/route.c:900 [inline] fib6_table_lookup+0x413/0xbb0 net/ipv6/route.c:2195 ip6_pol_route+0x273/0x15d0 net/ipv6/route.c:2231 pol_lookup_func include/net/ip6_fib.h:616 [inline] fib6_rule_lookup+0x286/0x790 net/ipv6/fib6_rules.c:119 ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline] ip6_route_output_flags+0x38e/0x610 net/ipv6/route.c:2651 ip6_route_output include/net/ip6_route.h:93 [inline] __nf_ip6_route+0x42/0xc0 net/ipv6/netfilter.c:113 nf_ip6_route include/linux/netfilter_ipv6.h:111 [inline] synproxy_send_tcp_ipv6+0x2a3/0x7c0 net/netfilter/nf_synproxy_core.c:835 synproxy_send_client_synack_ipv6+0x827/0xcc0 net/netfilter/nf_synproxy_core.c:897 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:90 [inline] nft_synproxy_do_eval+0x739/0xa60 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5828 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5941 process_backlog+0x662/0x15b0 net/core/dev.c:6289 __napi_poll+0xcb/0x490 net/core/dev.c:7106 napi_poll net/core/dev.c:7175 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7297 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 do_softirq+0x11b/0x1e0 kernel/softirq.c:462 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389 wg_socket_send_skb_to_peer+0x176/0x1d0 drivers/net/wireguard/socket.c:184 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x1dd/0x330 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10315 jiffies! g11417 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:25784 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5373 [inline] __schedule+0x186c/0x4be0 kernel/sched/core.c:6760 __schedule_loop kernel/sched/core.c:6837 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6852 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.13.0-syzkaller-04057-g15a901361ec3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1ba4/0x2d30 kernel/smp.c:885 Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 a0 e8 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 50 e4 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00 RSP: 0018:ffffc90000bc7640 EFLAGS: 00000293 RAX: ffffffff81939795 RBX: 1ffff110170e88e9 RCX: ffff88801daebc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000bc7840 R08: ffffffff81939760 R09: 1ffffffff285eb08 R10: dffffc0000000000 R11: fffffbfff285eb09 R12: ffff8880b863fac8 R13: ffff8880b8744748 R14: ffff8880b863fac0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563d62a92198 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x726/0xb30 arch/x86/kernel/alternative.c:2386 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244