rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14664/1:b..l rcu: (detected by 0, t=10503 jiffies, g=72737, q=2719 ncpus=2) task:syz.3.1727 state:R running task stack:26136 pid:14664 tgid:14664 ppid:11039 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 8b 60 00 11 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003d9f470 EFLAGS: 00000206 RAX: 3934f249062bbf00 RBX: 0000000000000202 RCX: 3934f249062bbf00 RDX: 0000000000000001 RSI: ffffffff8db7a779 RDI: ffffffff8be34100 RBP: ffff88802df58b18 R08: ffffc90003d9fc00 R09: 0000000000000000 R10: ffffc90003d9f5f8 R11: fffff520007b3ec1 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e139f20 R15: ffff88802df58000 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 discard_slab mm/slub.c:2753 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3218 put_cpu_partial+0x17c/0x250 mm/slub.c:3293 __slab_free+0x2d5/0x3c0 mm/slub.c:4550 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] __kmalloc_cache_noprof+0x1be/0x3d0 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] audit_log_d_path+0xb5/0x190 kernel/audit.c:2149 audit_log_d_path_exe+0x42/0x70 kernel/audit.c:2219 audit_log_task+0x2b3/0x3c0 kernel/auditsc.c:2957 audit_seccomp+0x86/0x190 kernel/auditsc.c:3004 seccomp_log kernel/seccomp.c:1033 [inline] __seccomp_filter+0x9a0/0x1a30 kernel/seccomp.c:1326 syscall_trace_enter+0xaa/0x160 kernel/entry/syscall-common.c:44 syscall_enter_from_user_mode_work include/linux/entry-common.h:95 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:125 [inline] do_syscall_64+0xd3/0x3b0 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4b6098eb69 RSP: 002b:00007ffc8a2994b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f4b60bb7ba0 RCX: 00007f4b6098eb69 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f4b60bb7ba0 R08: 0000000000003cbc R09: 0000000d8a2997af R10: 00007f4b60bb7ac0 R11: 0000000000000246 R12: 00000000000fedfe R13: 00007ffc8a2995b0 R14: ffffffffffffffff R15: 00007ffc8a2995d0 rcu: rcu_preempt kthread starved for 902 jiffies! g72737 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5925 Comm: kworker/1:5 Not tainted 6.16.0-next-20250731-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: wg-kex-wg1 wg_packet_handshake_receive_worker RIP: 0010:unwind_next_frame+0x116b/0x2390 arch/x86/kernel/unwind_orc.c:-1 Code: 4c 89 ef e8 f7 40 b0 00 48 8b 14 24 4d 89 65 00 41 0f b6 04 2f 84 c0 0f 85 f9 0f 00 00 c6 03 00 4c 8b 64 24 10 4c 8b 7c 24 28 <48> 8b 44 24 40 0f b6 04 28 84 c0 0f 85 8a 0d 00 00 41 0f b6 04 2f RSP: 0018:ffffc90000a07cf8 EFLAGS: 00000246 RAX: ffffc90000a07e18 RBX: ffffc90000a07e00 RCX: 0000000000000000 RDX: ffffffff9086b9ba RSI: 0000000000000000 RDI: ffffc90000a07e28 RBP: dffffc0000000000 R08: ffffc90000a07e27 R09: 0000000000000000 R10: ffffc90000a07e18 R11: fffff52000140fc5 R12: ffffc900046f7320 R13: ffffc90000a07e18 R14: ffffc90000a07dc8 R15: 1ffffffff210d737 FS: 0000000000000000(0000) GS:ffff888125d43000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86b41bdff8 CR3: 0000000031b0a000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4782 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1086 skb_release_all net/core/skbuff.c:1151 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1397 nft_synproxy_eval_v6+0x376/0x560 net/netfilter/nft_synproxy.c:91 nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x409/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:500 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:5979 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6092 process_backlog+0x60e/0x14f0 net/core/dev.c:6444 __napi_poll+0xc7/0x360 net/core/dev.c:7497 napi_poll net/core/dev.c:7560 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7687 handle_softirqs+0x283/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 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+0xd2/0x120 arch/x86/kernel/fpu/core.c:479 blake2s_compress+0x5f/0xd0 lib/crypto/x86/blake2s-glue.c:46 blake2s_final+0x116/0x260 lib/crypto/blake2s.c:55 hmac+0x293/0x330 drivers/net/wireguard/noise.c:333 kdf+0x182/0x270 drivers/net/wireguard/noise.c:375 mix_dh drivers/net/wireguard/noise.c:413 [inline] wg_noise_handshake_consume_initiation+0x242/0x900 drivers/net/wireguard/noise.c:608 wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline] wg_packet_handshake_receive_worker+0x5f2/0xfb0 drivers/net/wireguard/receive.c:213 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245