rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5495/1:b..l rcu: (detected by 1, t=10503 jiffies, g=23289, q=485978 ncpus=2) task:dhcpcd state:R running task stack:24856 pid:5495 tgid:5495 ppid:1 task_flags:0x400140 flags:0x00000002 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:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x4e/0x350 kernel/locking/lockdep.c:5829 Code: 48 8b 05 8d b1 0e 12 48 89 44 24 30 31 c0 66 90 65 8b 05 a9 b1 0e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 72 34 ee 0e <0f> 82 74 02 00 00 8b 35 ea 63 ee 0e 85 f6 0f 85 8d 00 00 00 48 8b RSP: 0018:ffffc900033c7668 EFLAGS: 00000297 RAX: 0000000000000000 RBX: ffffffff8e3c1580 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e3c1580 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 000000000000a702 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 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:2680 discard_slab mm/slub.c:2720 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3189 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_kmalloc+0x8a/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4331 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4343 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x245/0x580 security/tomoyo/file.c:723 security_file_ioctl+0x9b/0x240 security/security.c:2913 __do_sys_ioctl fs/ioctl.c:900 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0xb7/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f18b47c8d49 RSP: 002b:00007ffdc9b3d398 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00005633057bbb60 RCX: 00007f18b47c8d49 RDX: 00007ffdc9b3d3a0 RSI: 0000000000008921 RDI: 0000000000000011 RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000035 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc9b3d3a0 R13: 00005632d6952f88 R14: 00005633057bbb60 R15: 00005633057a61e0 rcu: rcu_preempt kthread starved for 944 jiffies! g23289 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:27704 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1102 Comm: kworker/u8:6 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:unwind_next_frame+0x4f3/0x20a0 arch/x86/kernel/unwind_orc.c:505 Code: 44 24 28 48 8b 74 24 20 48 8b 44 24 18 8b 90 b8 03 00 00 4c 89 f9 4c 89 c7 e8 19 f1 ff ff 48 89 c1 48 85 c0 0f 84 05 fe ff ff <48> b8 00 00 00 00 00 fc ff df 4c 8d 79 05 4c 89 fa 48 c1 ea 03 0f RSP: 0018:ffffc90000007088 EFLAGS: 00000286 RAX: ffffffff911a3f9a RBX: 0000000000000002 RCX: ffffffff911a3f9a RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff90970944 RBP: ffffc90000007190 R08: ffffffff911a3fa0 R09: 0000000000000000 R10: 0000000000000006 R11: 00000000000069ff R12: ffffc90000007198 R13: ffffc90000007148 R14: ffffc9000000717d R15: ffffffff8169ff43 FS: 0000000000000000(0000) GS:ffff8881249b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000032000 CR3: 0000000030b56000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 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 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4748 skb_kfree_head net/core/skbuff.c:1056 [inline] skb_kfree_head net/core/skbuff.c:1053 [inline] skb_free_head+0x18a/0x1d0 net/core/skbuff.c:1070 skb_release_data+0x7a5/0x960 net/core/skbuff.c:1097 skb_release_all net/core/skbuff.c:1162 [inline] __kfree_skb net/core/skbuff.c:1176 [inline] consume_skb net/core/skbuff.c:1408 [inline] consume_skb+0xbf/0x100 net/core/skbuff.c:1402 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline] nft_synproxy_do_eval+0xa6b/0xd80 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e6/0x1920 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:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [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:447 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:567 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5894 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6007 process_backlog+0x442/0x15e0 net/core/dev.c:6359 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7331 napi_poll net/core/dev.c:7395 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7517 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end+0x5e/0x70 arch/x86/kernel/fpu/core.c:460 blake2s_compress+0x7f/0xe0 arch/x86/crypto/blake2s-glue.c:49 blake2s_final+0xc9/0x150 lib/crypto/blake2s.c:54 hmac.constprop.0+0x252/0x420 drivers/net/wireguard/noise.c:325 kdf.constprop.0+0x14b/0x280 drivers/net/wireguard/noise.c:367 message_ephemeral+0x5f/0x70 drivers/net/wireguard/noise.c:493 wg_noise_handshake_create_initiation+0x2c6/0x650 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation+0x19a/0x360 drivers/net/wireguard/send.c:34 wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51 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