rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5178/1:b..l P5489/1:b..l rcu: (detected by 1, t=10503 jiffies, g=20705, q=1838420 ncpus=2) task:dhcpcd state:R running task stack:26264 pid:5489 tgid:5489 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: <TASK> 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:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870 Code: b2 0e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 12 36 ee 0e 0f 82 74 02 00 00 8b 35 aa 65 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 e9 b1 0e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90003e0f370 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c15c0 RCX: 000000007568e256 RDX: 0000000000000000 RSI: ffffffff8dbc9fb7 RDI: ffffffff8bf46340 RBP: 0000000000000002 R08: a0d9e9811d6e44ec R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 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] __page_table_check_zero+0x13d/0x5b0 mm/page_table_check.c:138 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1263 [inline] __free_frozen_pages+0x704/0xff0 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_node_track_caller_noprof+0x221/0x510 mm/slub.c:4350 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599 __alloc_skb+0x166/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1340 [inline] alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6639 sock_alloc_send_pskb+0x7fb/0x990 net/core/sock.c:2954 unix_dgram_sendmsg+0x463/0x1910 net/unix/af_unix.c:2007 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] sock_write_iter+0x4fc/0x5b0 net/socket.c:1131 do_iter_readv_writev+0x654/0x950 fs/read_write.c:825 vfs_writev+0x353/0xdc0 fs/read_write.c:1055 do_writev+0x295/0x330 fs/read_write.c:1101 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: 0033:0x7fee73fefe03 RSP: 002b:00007ffda6ea16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007ffda6ea19e8 RCX: 00007fee73fefe03 RDX: 0000000000000005 RSI: 00007ffda6ea16c0 RDI: 000000000000000a RBP: 0000000000004801 R08: 000000000000000a R09: 00007ffda6ea1700 R10: 00007ffda6ea1708 R11: 0000000000000246 R12: 000055638b1d3460 R13: 000055636c11ef88 R14: 00000000ffffffff R15: 000055638b1dfea0 </TASK> task:syslogd state:R running task stack:25160 pid:5178 tgid:5178 ppid:1 task_flags:0x400000 flags:0x00000002 Call Trace: <TASK> context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 preempt_schedule_notrace+0x62/0xe0 kernel/sched/core.c:7040 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:737 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x2cd/0x350 kernel/locking/lockdep.c:5829 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_check_open_permission+0x2ab/0x3c0 security/tomoyo/file.c:771 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334 security_file_open+0x84/0x1e0 security/security.c:3114 do_dentry_open+0x596/0x1c10 fs/open.c:933 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3845 [inline] path_openat+0x1e5e/0x2d40 fs/namei.c:4004 do_filp_open+0x20b/0x470 fs/namei.c:4031 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 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: 0033:0x7fd695a179a4 RSP: 002b:00007fff5b8557d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000555a0e5932c0 RCX: 00007fd695a179a4 RDX: 0000000000000d41 RSI: 00007fd695bb6443 RDI: 00000000ffffff9c RBP: 00007fd695bb6443 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000d41 R13: 0000000067fb4e44 R14: 0000000000000004 R15: 0000555a0e593410 </TASK> rcu: rcu_preempt kthread starved for 6855 jiffies! g20705 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:27192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: <TASK> 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 </TASK> 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: 8119 Comm: kworker/u8:11 Not tainted 6.15.0-rc1-syzkaller-00308-gecd5d67ad602 #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:task_irq_context kernel/locking/lockdep.c:4684 [inline] RIP: 0010:__lock_acquire+0x17b/0x1ba0 kernel/locking/lockdep.c:5172 Code: 20 48 8b 84 24 b0 00 00 00 48 89 43 08 41 8b 8e d4 0a 00 00 31 c0 65 8b 15 8a 0f 0f 12 85 c9 44 89 e9 44 8b ac 24 c8 00 00 00 <0f> 95 c0 85 d2 0f 95 c2 41 c1 e2 0f c1 e1 10 0f b6 d2 45 0f b7 d2 RSP: 0018:ffffc90000006b90 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff888031f58c08 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff888031f58be0 RDI: ffff888031f58c08 RBP: ffff888031f58af0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff8e3c15c0 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888031f58000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff320c9c3d4 CR3: 000000004120c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 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 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:4151 [inline] slab_alloc_node mm/slub.c:4200 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4207 dst_alloc+0x99/0x1a0 net/core/dst.c:89 rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1638 __mkroute_output net/ipv4/route.c:2632 [inline] ip_route_output_key_hash_rcu+0x87a/0x28f0 net/ipv4/route.c:2854 ip_route_output_key_hash+0x137/0x2e0 net/ipv4/route.c:2683 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2911 ip_route_output_key include/net/route.h:179 [inline] ip_route_me_harder+0x565/0x12f0 net/ipv4/netfilter.c:53 synproxy_send_tcp.isra.0+0x2fa/0x630 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x6f6/0x8f0 net/netfilter/nf_synproxy_core.c:484 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+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:5885 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5998 process_backlog+0x442/0x15e0 net/core/dev.c:6350 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7322 napi_poll net/core/dev.c:7386 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7508 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 </IRQ> <TASK> __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] wg_index_hashtable_insert+0x108/0x9f0 drivers/net/wireguard/peerlookup.c:126 wg_noise_handshake_create_initiation+0x4a0/0x650 drivers/net/wireguard/noise.c:569 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 </TASK>