ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on vlan2! rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5830/3:b..l rcu: (detected by 1, t=10502 jiffies, g=6121, q=6316 ncpus=2) task:syz-executor state:R running task stack:24200 pid:5830 tgid:5830 ppid:5829 task_flags:0x400100 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x107/0x120 kernel/softirq.c:414 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline] __dev_queue_xmit+0xb06/0x4490 net/core/dev.c:4740 dev_queue_xmit include/linux/netdevice.h:3361 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:235 __ip_finish_output.part.0+0x1b4/0x350 net/ipv4/ip_output.c:313 __ip_finish_output net/ipv4/ip_output.c:301 [inline] ip_finish_output net/ipv4/ip_output.c:323 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x35e/0xa10 net/ipv4/ip_output.c:436 dst_output include/net/dst.h:461 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1d30/0x2620 net/ipv4/ip_output.c:532 __tcp_transmit_skb+0x265f/0x3df0 net/ipv4/tcp_output.c:1479 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline] tcp_write_xmit+0x1274/0x84e0 net/ipv4/tcp_output.c:2833 tcp_sendmsg_locked+0x36cd/0x42a0 net/ipv4/tcp.c:1336 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1393 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] sock_write_iter+0x4aa/0x5b0 net/socket.c:1179 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d0/0x11d0 fs/read_write.c:686 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd51878d660 RSP: 002b:00007ffebb386938 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000050aeada80 RCX: 00007fd51878d660 RDX: 0000000000037058 RSI: 00007fd5135c8fa8 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000007 R09: 00000000005ffde8 R10: 4461394b56a159fc R11: 0000000000000202 R12: 0000000000037058 R13: 000055556f77ae10 R14: 00007ffebb386e40 R15: 00007fd5135c8fa8 rcu: rcu_preempt kthread starved for 8982 jiffies! g6121 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:29136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.17.0-rc1-syzkaller-00224-g8d561baae505 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x41/0xc0 kernel/rcu/tree.c:751 Code: d7 93 89 c5 83 f8 07 0f 87 82 00 00 00 48 8d 3c ed 60 de f5 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <75> 5c 48 03 1c ed 60 de f5 8d 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffffc90000006e80 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffffff93d772a8 RCX: 0000000000000002 RDX: 1ffffffff1bebbcc RSI: ffffffff8c162680 RDI: ffffffff8df5de60 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff922b0000 R11: 00000000000a93a0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881246bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000001ad030 CR3: 000000005c82d000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x2cd/0x350 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:776 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x8d/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26 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:330 [inline] __kasan_slab_alloc+0x89/0x90 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+0x1cb/0x3b0 mm/slub.c:4236 skb_clone+0x190/0x3f0 net/core/skbuff.c:2049 deliver_clone net/bridge/br_forward.c:125 [inline] br_flood+0x37c/0x650 net/bridge/br_forward.c:249 br_handle_frame_finish+0xf2d/0x1ca0 net/bridge/br_input.c:221 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0xad8/0x14b0 net/bridge/br_input.c:434 __netif_receive_skb_core.constprop.0+0xa25/0x48c0 net/core/dev.c:5866 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5977 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 process_backlog+0x442/0x15e0 net/core/dev.c:6444 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494 napi_poll net/core/dev.c:7557 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 7c 62 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 92 16 00 fb f4 4c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c2 RAX: 000000000016f474 RBX: 0000000000000000 RCX: ffffffff8b937c29 RDX: ffffed1017086656 RSI: ffffffff8c162680 RDI: ffffffff819133c1 RBP: fffffbfff1c52ef8 R08: 0000000000000000 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e2977c0 R14: ffffffff90ab3b90 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148 net_ratelimit: 169725 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on vlan2! bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:f9:e4:d6:20:c6, 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:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on vlan2! 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 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:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on vlan2! net_ratelimit: 228990 callbacks suppressed 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on vlan2! 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 veth0_to_bridge 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:ea:f9:e4:d6:20:c6, vlan:0) ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on vlan2! 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:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)