bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13949/1:b..l rcu: (detected by 1, t=10503 jiffies, g=63241, q=1092 ncpus=2) task:syz.2.3017 state:R running task stack:25232 pid:13949 tgid:13948 ppid:12850 task_flags:0x40044c 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:unwind_next_frame+0x1166/0x2390 arch/x86/kernel/unwind_orc.c:-1 Code: 6c 24 50 74 0c 4c 89 ef e8 27 90 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 RSP: 0018:ffffc900001f6b58 EFLAGS: 00000246 RAX: ffffc900001f6c78 RBX: ffffc900001f6c60 RCX: 0000000000000000 RDX: ffffffff907414d6 RSI: 0000000000000000 RDI: ffffc900001f6c88 RBP: dffffc0000000000 R08: ffffc900001f6c87 R09: 0000000000000000 R10: ffffc900001f6c78 R11: fffff5200003ed91 R12: ffffc900001f7ed0 R13: ffffc900001f6c78 R14: ffffc900001f6c28 R15: ffffc900001f6c70 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_unref_folios+0xdbd/0x1520 mm/page_alloc.c:2952 folios_put_refs+0x559/0x640 mm/swap.c:997 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404 zap_pte_range mm/memory.c:1893 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x3b37/0x4370 mm/memory.c:2017 unmap_single_vma mm/memory.c:2060 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2104 exit_mmap+0x248/0xb50 mm/mmap.c:1280 __mmput+0x118/0x420 kernel/fork.c:1133 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6c34b8ebe9 RSP: 002b:00007f6c32dee0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6c34db5fa8 RCX: 00007f6c34b8ebe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6c34db5fa8 RBP: 00007f6c34db5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6c34db6038 R14: 00007ffcc50d3270 R15: 00007ffcc50d3358 rcu: rcu_preempt kthread starved for 2853 jiffies! g63241 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:27496 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+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: CPU: 1 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.17.0-rc2-next-20250818-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:debug_lockdep_rcu_enabled+0x2d/0x40 kernel/rcu/update.c:320 Code: fa 31 c0 83 3d f7 f9 60 04 00 74 1e 83 3d 1a 2a 61 04 00 74 15 65 48 8b 0c 25 08 00 e5 92 31 c0 83 b9 ec 0a 00 00 00 0f 94 c0 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 RSP: 0018:ffffc90000a07c50 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8169eaa4 RCX: af2d2c9ef4f90300 RDX: 0000000000000000 RSI: ffffffff8c04e6e0 RDI: ffffffff8c04e6a0 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000a07dd8 R11: fffff52000140fbd R12: 1ffff92000140fb1 R13: ffffc90000a07dc0 R14: ffffc90000a07d88 R15: ffffffff81731195 FS: 0000000000000000(0000) GS:ffff8881258d0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff554c00218 CR3: 00000000633da000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:842 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xcb/0x2390 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 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 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 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] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236 skb_clone+0x212/0x3a0 net/core/skbuff.c:2049 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x414/0x6a0 net/bridge/br_forward.c:250 br_handle_frame_finish+0x14b4/0x19b0 net/bridge/br_input.c:221 br_nf_hook_thresh+0x3c3/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:434 __netif_receive_skb_core+0x10b9/0x4020 net/core/dev.c:5866 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6092 process_backlog+0x60e/0x14f0 net/core/dev.c:6444 __napi_poll+0xc7/0x360 net/core/dev.c:7494 napi_poll net/core/dev.c:7557 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7684 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 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:42 [inline] wg_packet_handshake_send_worker+0x1e3/0x320 drivers/net/wireguard/send.c:51 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+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:56:d0:68:10:36:aa, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:56:d0:68:10:36:aa, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)