bridge0: received packet on veth0_to_bridge with own address as source address (addr:7a:86:01:9c:d5:9c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5993/1:b..l rcu: (detected by 0, t=10503 jiffies, g=9517, q=703 ncpus=2) task:syz.1.59 state:R running task stack:25552 pid:5993 ppid:5769 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x200f/0x2970 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1316 [inline] nlmsg_new include/net/netlink.h:1010 [inline] netlink_ack+0x376/0x1180 net/netlink/af_netlink.c:2482 netlink_rcv_skb+0x2c5/0x4d0 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648 __sys_sendmsg net/socket.c:2677 [inline] __do_sys_sendmsg net/socket.c:2686 [inline] __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7901b9c819 RSP: 002b:00007f79029cd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7901e16180 RCX: 00007f7901b9c819 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000b RBP: 00007f7901c32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7901e16218 R14: 00007f7901e16180 R15: 00007fffd53f22f8 rcu: rcu_preempt kthread starved for 8689 jiffies! g9517 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:27656 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5987 Comm: syz.1.59 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__update_cpu_freelist_fast mm/slub.c:3050 [inline] RIP: 0010:__slab_alloc_node mm/slub.c:3410 [inline] RIP: 0010:slab_alloc_node mm/slub.c:3485 [inline] RIP: 0010:slab_alloc mm/slub.c:3503 [inline] RIP: 0010:__kmem_cache_alloc_lru mm/slub.c:3510 [inline] RIP: 0010:kmem_cache_alloc+0xb6/0x2d0 mm/slub.c:3519 Code: e7 00 00 00 48 83 78 10 00 0f 84 dc 00 00 00 41 8b 45 28 4a 8b 1c 38 48 8d 4f 08 4d 8b 45 00 48 89 fa 4c 89 f8 65 49 0f c7 08 <0f> 1f 00 48 31 fa 4c 31 f8 48 09 d0 75 b0 41 8b 45 28 0f 0d 0c 03 RSP: 0018:ffffc900001eff80 EFLAGS: 000002c6 RAX: ffff88807f48f700 RBX: ffff88807f48f800 RCX: 00000000000e5419 RDX: 00000000000e5411 RSI: 00000000000000b8 RDI: 00000000000e5411 RBP: 0000000000000820 R08: 0000000000044250 R09: 1ffff1100fe91ea0 R10: dffffc0000000000 R11: ffffed100fe91ea1 R12: 00000000000000b8 R13: ffff888141a653c0 R14: ffff888141a653c0 R15: ffff88807f48f700 FS: 00007f79029ee6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000014000 CR3: 000000007b8f5000 CR4: 00000000003506e0 Call Trace: skb_ext_maybe_cow net/core/skbuff.c:6664 [inline] skb_ext_add+0x1b3/0x8e0 net/core/skbuff.c:6738 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:165 [inline] br_nf_forward_ip+0xc6/0x1110 net/bridge/br_netfilter_hooks.c:709 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:259 [inline] NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302 __br_forward+0x433/0x610 net/bridge/br_forward.c:115 br_handle_frame_finish+0x13c5/0x18f0 net/bridge/br_input.c:215 br_nf_hook_thresh+0x3cd/0x4a0 net/bridge/br_netfilter_hooks.c:1184 br_nf_pre_routing_finish_ipv6+0x9dc/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x349/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x1245/0x14d0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5528 __netif_receive_skb_one_core net/core/dev.c:5632 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5748 process_backlog+0x391/0x6f0 net/core/dev.c:6076 __napi_poll+0xc0/0x460 net/core/dev.c:6638 napi_poll net/core/dev.c:6705 [inline] net_rx_action+0x616/0xc40 net/core/dev.c:6841 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5255 Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 b0 63 32 09 e8 9b 29 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90004e477d8 EFLAGS: 00000286 RAX: 62350791af67f800 RBX: 0000000000000000 RCX: 62350791af67f800 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8de0 RBP: ffffc90004e47830 R08: ffffffff8e8b0c2f R09: 1ffffffff1d16185 R10: dffffc0000000000 R11: fffffbfff1d16186 R12: ffff88802399da00 R13: dffffc0000000000 R14: ffff88807fc05a00 R15: ffff8880b8f3cac8 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x155b/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:task_work_run+0x1d9/0x260 kernel/task_work.c:247 Code: d2 85 00 49 8b 5d 00 49 8d 7d 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 c3 d2 85 00 4c 89 ef 41 ff 55 08 48 89 5c 24 40 <48> c7 c7 80 1e ca 8a be f7 00 00 00 31 d2 e8 f4 c3 04 00 2e 2e 2e RSP: 0018:ffffc90004e47bc0 EFLAGS: 00000246 RAX: 62350791af67f800 RBX: 0000000000000000 RCX: 1ffff920009c8f64 RDX: 0000000000000003 RSI: ffff8880b8f00000 RDI: 0000000000000001 RBP: ffffc90004e47c78 R08: ffffffff8e8b0c2f R09: 1ffffffff1d16185 R10: dffffc0000000000 R11: fffffbfff1d16186 R12: dffffc0000000000 R13: ffff88802399ef80 R14: ffff88802399e400 R15: ffff88802399e368 get_signal+0x1235/0x13f0 kernel/signal.c:2678 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7901b9c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f79029ee028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: fffffffffffffffc RBX: 00007f7901e16090 RCX: 00007f7901b9c819 RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 000000000000000c RBP: 00007f7901c32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7901e16128 R14: 00007f7901e16090 R15: 00007fffd53f22f8 net_ratelimit: 9130 callbacks suppressed 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 veth0_to_bridge with own address as source address (addr:7a:86:01:9c:d5:9c, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, 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 veth0_to_bridge with own address as source address (addr:ba:2a:44:37:cb:67, 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 veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 20811 callbacks suppressed 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ba:2a:44:37:cb:67, 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 veth0_to_bridge with own address as source address (addr:7a:86:01:9c:d5:9c, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:7a:86:01:9c:d5:9c, vlan:0)