bridge0: received packet on veth0_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): P27744/1:b.el rcu: (detected by 1, t=10503 jiffies, g=196141, q=1874 ncpus=2) task:syz.1.6128 state:R running task stack:24472 pid:27744 tgid:27739 ppid:27025 task_flags:0x40054c flags:0x08080001 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x157c/0x52b0 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:748 [inline] RIP: 0010:rcu_is_watching+0x4/0xb0 kernel/rcu/tree.c:751 Code: 76 8e e8 2f e0 38 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 41 56 53 65 ff 05 e0 7a 6e 11 e8 4b 87 f6 09 89 c3 83 f8 08 RSP: 0000:ffffc9000b8ef7c8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88806de48000 RDX: 0000000000000000 RSI: ffffffff8239d69a RDI: ffffffff8e75e3e0 RBP: dffffc0000000000 R08: ffff88801de5ccdf R09: 1ffff11003bcb99b R10: dffffc0000000000 R11: ffffed1003bcb99c R12: ffffffff8239d69a R13: ffffffff8239d69a R14: ffffffff8e75e3e0 R15: ffff88801de5cce0 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3a0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] __page_table_check_zero+0x397/0x3e0 mm/page_table_check.c:145 page_table_check_free include/linux/page_table_check.h:46 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc10/0xd80 mm/page_alloc.c:2972 vfree+0x25a/0x400 mm/vmalloc.c:3479 kcov_put kernel/kcov.c:442 [inline] kcov_close+0x28/0x50 kernel/kcov.c:543 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x69b/0x2310 kernel/exit.c:971 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] __do_fast_syscall_32+0x415/0x640 arch/x86/entry/syscall_32.c:310 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf705ef6c RSP: 002b:00000000f540b5bc EFLAGS: 00000206 ORIG_RAX: 00000000000000f0 RAX: fffffffffffffe00 RBX: 00000000f74550b8 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f74550bc RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 429 jiffies! g196141 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:27976 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x157c/0x52b0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 7703 Comm: kworker/0:10 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:-1 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x2a8/0x23c0 arch/x86/kernel/unwind_orc.c:510 Code: 18 04 00 00 45 39 e8 48 bd 00 00 00 00 00 fc ff df 0f 84 1c 04 00 00 4a 8d 14 ad 04 3b 23 90 45 29 e8 4a 8d 1c 82 48 83 c3 fc <49> 89 d5 48 39 da 0f 86 21 02 00 00 49 29 d5 49 c1 fd 02 4a 8d 04 RSP: 0018:ffffc90000006dd8 EFLAGS: 00000293 RAX: ffffffff912b784e RBX: ffffffff9082d764 RCX: 0000000080000100 RDX: ffffffff9082d764 RSI: ffffffff912b7848 RDI: ffffffff8c2798a0 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8e75e3e0 R10: ffffc90000006ef8 R11: ffffffff81af8200 R12: ffffffff8974b8f6 R13: 000000000017e718 R14: ffffc90000006ea8 R15: 00000000000874b8 FS: 0000000000000000(0000) GS:ffff8881254a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f51c9de3 CR3: 000000000e54a000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4459 [inline] slab_alloc_node mm/slub.c:4788 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4795 skb_clone+0x212/0x3a0 net/core/skbuff.c:2120 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x8cf/0xb80 net/bridge/br_forward.c:250 br_handle_frame_finish+0x1492/0x1b40 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 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:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3150 net/core/dev.c:6036 __netif_receive_skb_one_core net/core/dev.c:6147 [inline] __netif_receive_skb net/core/dev.c:6262 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6614 __napi_poll+0xae/0x340 net/core/dev.c:7678 napi_poll net/core/dev.c:7741 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7893 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:395 [inline] ptr_ring_consume_bh include/linux/ptr_ring.h:377 [inline] wg_packet_handshake_receive_worker+0x2e6/0x10c0 drivers/net/wireguard/receive.c:212 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 18861 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c6:28:17:35:fc:9f, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c6:28:17:35:fc:9f, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) net_ratelimit: 20775 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c6:28:17:35:fc:9f, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c6:28:17:35:fc:9f, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)