bridge0: received packet on bridge_slave_0 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): P9999/1:b..l P10000/1:b..l rcu: (detected by 1, t=10502 jiffies, g=39233, q=425 ncpus=2) task:syz.1.1259 state:R running task stack:25792 pid:10000 tgid:9995 ppid:5839 task_flags:0x40044c flags:0x10080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1568/0x5290 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:memset+0x4/0x20 arch/x86/lib/memset_64.S:33 Code: eb 0c 48 83 fa 01 72 06 44 8a 1e 44 88 1f e9 03 c0 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 2a 49 89 f9 40 88 f0 48 89 d1 f3 aa 4c 89 c8 e9 d7 bf 02 00 90 RSP: 0000:ffffc90002ed6bb0 EFLAGS: 00000202 RAX: ffffc90002ed7401 RBX: ffffc90002ed6cc0 RCX: ffffffff8175c07e RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90002ed6cd8 RBP: dffffc0000000000 R08: ffffc90002ed6ce7 R09: 1ffff920005dad9c R10: dffffc0000000000 R11: fffff520005dad9d R12: ffffc90002ed6cd8 R13: 1ffff920005dad93 R14: ffffc90002ed6c88 R15: ffffc90002ed6cd0 unwind_next_frame+0xeae/0x23c0 arch/x86/kernel/unwind_orc.c:607 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xdce/0x1510 mm/page_alloc.c:3035 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:354 __tlb_batch_free_encoded_pages mm/mmu_gather.c:137 [inline] tlb_batch_pages_flush mm/mmu_gather.c:150 [inline] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405 zap_pte_range mm/memory.c:1897 [inline] zap_pmd_range mm/memory.c:1950 [inline] zap_pud_range mm/memory.c:1978 [inline] zap_p4d_range mm/memory.c:1999 [inline] unmap_page_range+0x39a3/0x4030 mm/memory.c:2020 unmap_single_vma mm/memory.c:2062 [inline] unmap_vmas+0x3c0/0x5c0 mm/memory.c:2104 exit_mmap+0x251/0xb30 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2310 kernel/exit.c:959 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: 0023:0xf7fe5f6c RSP: 002b:00000000f54855bc EFLAGS: 00000206 ORIG_RAX: 00000000000000f0 RAX: fffffffffffffe00 RBX: 00000000f74a5020 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f74a5024 RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 task:syz.2.1260 state:R running task stack:26176 pid:9999 tgid:9998 ppid:5837 task_flags:0x400040 flags:0x10080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1568/0x5290 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:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d e4 bb 54 0c 48 89 de 5b e9 13 a4 5d 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d c8 e5 51 11 65 8b 15 e9 e5 51 11 81 e2 00 01 ff 00 74 RSP: 0000:ffffc90002ee74b8 EFLAGS: 00000202 RAX: ffffffff823976f8 RBX: 0000000000000001 RCX: 0000000080000001 RDX: ffff88802eef0000 RSI: ffffffff8c2764e0 RDI: ffffffff8c2764a0 RBP: 0000000000000000 R08: ffffffff823973f2 R09: ffffffff8e75e0a0 R10: dffffc0000000000 R11: fffff940002d4a1f R12: 0000000000000000 R13: 0000000000000000 R14: ffffea00016a50c0 R15: 0000004de5aee0e7 rcu_read_unlock include/linux/rcupdate.h:879 [inline] page_ext_put+0x38/0xc0 mm/page_ext.c:552 __reset_page_owner+0x67/0x1f0 mm/page_owner.c:312 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xbf8/0xd70 mm/page_alloc.c:2973 __slab_free+0x263/0x2b0 mm/slub.c:5490 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 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 vm_area_dup+0x2b/0x680 mm/vma_init.c:123 dup_mmap+0x896/0x1bb0 mm/mmap.c:1773 dup_mm kernel/fork.c:1530 [inline] copy_mm+0x13b/0x4b0 kernel/fork.c:1582 copy_process+0x18b6/0x3cf0 kernel/fork.c:2223 kernel_clone+0x248/0x870 kernel/fork.c:2654 __do_sys_clone3 kernel/fork.c:2956 [inline] __se_sys_clone3+0x33c/0x360 kernel/fork.c:2935 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f37f6c RSP: 002b:00000000f53f63dc EFLAGS: 00000206 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00000000f53f6410 RCX: 0000000000000058 RDX: 0000000000000000 RSI: 0000000080801400 RDI: 0000000000000001 RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 1651 jiffies! g39233 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:28088 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1568/0x5290 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:check_preemption_disabled+0x3/0xe0 lib/smp_processor_id.c:13 Code: 27 8c 48 c7 c6 e0 64 27 8c eb 1c 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 55 41 57 <41> 56 53 65 8b 05 57 13 79 07 65 8b 0d 4c 13 79 07 f7 c1 ff ff ff RSP: 0018:ffffc90000007488 EFLAGS: 00000046 RAX: 0000000080000301 RBX: ffffffff81872111 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: ffffffff8df41fb8 RDI: ffffffff8c276500 RBP: ffffc900000076e0 R08: ffffc9000000764f R09: 0000000000000000 R10: ffffc90000007630 R11: fffff52000000eca R12: ffff88807f4a28f0 R13: dffffc0000000000 R14: ffffffff8a5cd15f R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881254bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f42af5d8 CR3: 0000000034bba000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_off+0x8d/0xd0 kernel/locking/lockdep.c:4495 trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104 __local_bh_enable_ip+0x71/0x130 kernel/softirq.c:432 local_bh_enable include/linux/bottom_half.h:33 [inline] ip6t_do_table+0x137d/0x1560 net/ipv6/netfilter/ip6_tables.c:375 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] br_nf_pre_routing_ipv6+0x59f/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/0x30a0 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb net/core/dev.c:6265 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6617 __napi_poll+0xae/0x340 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7896 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 04 7c 02 c3 cc cc cc cc cc cc cc 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 43 68 2c 00 fb f4 7c e8 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000242 RAX: 00000000012ae40b RBX: ffffffff8199857d RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dedcffb RDI: ffffffff8c276500 RBP: ffffffff8e407eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff90105470 R13: 1ffffffff1c929d8 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1bd/0x500 kernel/sched/idle.c:332 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x380/0x3d0 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 net_ratelimit: 32877 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:72:71:7a:a4:31:03, 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:c2:1b:a9:62:76:e7, 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 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:c2:1b:a9:62:76:e7, 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)