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): P5766/1:b..l rcu: (detected by 0, t=10503 jiffies, g=11081, q=1032 ncpus=2) task:syz-executor state:R running task stack:21704 pid:5766 ppid:1 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:1154 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35a/0x400 mm/slub.c:3736 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] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 ptlock_alloc+0x20/0x70 mm/memory.c:6177 ptlock_init include/linux/mm.h:2964 [inline] pagetable_pte_ctor include/linux/mm.h:2987 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:71 [inline] pte_alloc_one+0xcc/0x530 arch/x86/mm/pgtable.c:33 __pte_alloc+0x22/0x2a0 mm/memory.c:438 copy_pte_range mm/memory.c:1029 [inline] copy_pmd_range mm/memory.c:1168 [inline] copy_pud_range mm/memory.c:1205 [inline] copy_p4d_range mm/memory.c:1229 [inline] copy_page_range+0x2d96/0x3670 mm/memory.c:1323 dup_mmap kernel/fork.c:764 [inline] dup_mm kernel/fork.c:1692 [inline] copy_mm+0x11cb/0x1d50 kernel/fork.c:1741 copy_process+0x16f7/0x3d80 kernel/fork.c:2506 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 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: 0033:0x7f4ab75c3752 RSP: 002b:00007ffd718ea0f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd718ea0f0 RCX: 00007f4ab75c3752 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd718ea27c R08: 0000000000000000 R09: 0000000000000001 R10: 000055558786b7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000017aaa R15: 00007ffd718ea2d0 rcu: rcu_preempt kthread starved for 575 jiffies! g11081 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: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: CPU: 0 PID: 6067 Comm: syz.3.81 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90000006898 EFLAGS: 00000206 RAX: b1cff16a0febc000 RBX: ffff8880238bbc00 RCX: b1cff16a0febc000 RDX: 0000000000000100 RSI: ffffffff8acada80 RDI: ffffffff8b1c80e0 RBP: 0000000000000001 R08: ffffffff911be52f R09: 1ffffffff2237ca5 R10: dffffc0000000000 R11: fffffbfff2237ca6 R12: 0000000000000004 R13: 0000000000000246 R14: ffffffff8d131fe0 R15: ffff8880238bc780 FS: 00007f6b3c82f6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc5a6b0fe80 CR3: 00000000744a8000 CR4: 00000000003506f0 Call Trace: skb_dst include/linux/skbuff.h:1119 [inline] br_drop_fake_rtable include/linux/netfilter_bridge.h:21 [inline] br_dev_queue_push_xmit+0x106/0x870 net/bridge/br_forward.c:39 NF_HOOK+0x66e/0x700 include/linux/netfilter.h:304 br_nf_post_routing+0xb41/0xfb0 net/bridge/br_netfilter_hooks.c:977 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_finish+0xd3/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1184 [inline] br_nf_forward_finish+0xa51/0xe80 net/bridge/br_netfilter_hooks.c:684 NF_HOOK+0x66e/0x700 include/linux/netfilter.h:304 br_nf_forward_ip+0xcc1/0x1110 net/bridge/br_netfilter_hooks.c:754 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 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb5/0x150 net/bridge/br_forward.c:191 br_flood+0x31b/0x670 net/bridge/br_forward.c:237 br_handle_frame_finish+0x149b/0x19b0 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+0x96b/0x14e0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5532 __netif_receive_skb_one_core net/core/dev.c:5636 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5752 process_backlog+0x396/0x700 net/core/dev.c:6080 __napi_poll+0xc0/0x460 net/core/dev.c:6642 napi_poll net/core/dev.c:6709 [inline] net_rx_action+0x616/0xc50 net/core/dev.c:6846 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:slab_update_freelist mm/slub.c:617 [inline] RIP: 0010:__slab_free+0x22f/0x400 mm/slub.c:3682 Code: 75 33 48 89 f7 4c 89 d6 4c 89 ea 48 89 d9 4d 89 f8 e8 b5 df ff ff 41 89 c7 eb 55 4c 89 f9 4c 89 d0 4c 89 ea f0 48 0f c7 4e 20 <0f> 84 86 00 00 00 e9 9f fe ff ff 48 89 6c 24 08 48 89 f5 4c 89 64 RSP: 0018:ffffc9000bbe7250 EFLAGS: 00000242 RAX: ffff88802e4bda50 RBX: ffff88802e4bd2d0 RCX: 0000000000220008 RDX: 0000000000220009 RSI: ffffea0000b92f40 RDI: 0000000000000000 RBP: ffff888019e4d280 R08: 0000000000000001 R09: 0000000000000000 R10: ffff88802e4bda50 R11: fffffbfff2237ca6 R12: ffff888019e4d280 R13: 0000000000220009 R14: 0000000000220008 R15: 0000000000220008 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] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 ptlock_alloc+0x20/0x70 mm/memory.c:6177 ptlock_init include/linux/mm.h:2964 [inline] pagetable_pte_ctor include/linux/mm.h:2987 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:71 [inline] pte_alloc_one+0xcc/0x530 arch/x86/mm/pgtable.c:33 __pte_alloc+0x22/0x2a0 mm/memory.c:438 copy_pte_range mm/memory.c:1029 [inline] copy_pmd_range mm/memory.c:1168 [inline] copy_pud_range mm/memory.c:1205 [inline] copy_p4d_range mm/memory.c:1229 [inline] copy_page_range+0x2d96/0x3670 mm/memory.c:1323 dup_mmap kernel/fork.c:764 [inline] dup_mm kernel/fork.c:1692 [inline] copy_mm+0x11cb/0x1d50 kernel/fork.c:1741 copy_process+0x16f7/0x3d80 kernel/fork.c:2506 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 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: 0033:0x7f6b3b99acb9 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:00007f6b3c82efd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f6b3bc15fa0 RCX: 00007f6b3b99acb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6b3ba08bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6b3bc16038 R14: 00007f6b3bc15fa0 R15: 00007ffd53b994f8 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: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:06:7d:9a:1c:f0:98, 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:06:7d:9a:1c:f0:98, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:06:7d:9a:1c:f0:98, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)