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): P5771/1:b..l rcu: (detected by 1, t=10503 jiffies, g=11409, q=790 ncpus=2) task:syz-executor state:R running task stack:21488 pid:5771 ppid:5768 flags:0x00004000 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 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1107 [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+0x2ba0/0x3670 mm/memory.c:1323 dup_mmap kernel/fork.c:768 [inline] dup_mm kernel/fork.c:1693 [inline] copy_mm+0x1281/0x1d80 kernel/fork.c:1742 copy_process+0x16f7/0x3d80 kernel/fork.c:2507 kernel_clone+0x24b/0x8a0 kernel/fork.c:2915 __do_sys_clone kernel/fork.c:3058 [inline] __se_sys_clone kernel/fork.c:3042 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3042 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: 0033:0x7f08e8bc5292 RSP: 002b:00007ffd5f7326a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd5f7326a0 RCX: 00007f08e8bc5292 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd5f73282c R08: 0000000000000000 R09: 0000000000000001 R10: 000055555d4297d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000001a5d6 R15: 00007ffd5f732880 rcu: rcu_preempt kthread starved for 1520 jiffies! g11409 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6196 Comm: syz.2.115 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__lock_acquire+0xde1/0x7d40 kernel/locking/lockdep.c:5110 Code: 00 00 00 fc ff df 48 0f a3 1d ab 17 b4 0f 0f 83 c5 50 00 00 49 8d 9d d0 0a 00 00 48 89 d8 48 c1 e8 03 48 89 84 24 b8 00 00 00 <42> 80 3c 00 00 74 12 48 89 df e8 20 1c 77 00 49 b8 00 00 00 00 00 RSP: 0018:ffffc90000006880 EFLAGS: 00000802 RAX: 1ffff1100fccc51a RBX: ffff88807e6628d0 RCX: ffffffff81683d43 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911c5508 RBP: ffffc90000006ac8 R08: dffffc0000000000 R09: 1ffffffff2238aa1 R10: dffffc0000000000 R11: fffffbfff2238aa2 R12: 0000000000000000 R13: ffff88807e661e00 R14: ffff88807e662958 R15: ffff88807e662978 FS: 00007f4ba9e456c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc1ba7f0700 CR3: 000000005d8d5000 CR4: 00000000003506f0 Call Trace: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162 hrtimer_interrupt+0xfc/0x9c0 kernel/time/hrtimer.c:1857 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:216 Code: 89 fb e8 13 00 00 00 48 8b 3d 1c f5 03 0d 48 89 de 5b e9 e3 67 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d b0 93 7c 7e <65> 8b 15 b1 93 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90000006ed8 EFLAGS: 00000246 RAX: ffffffff893a0b0d RBX: ffff88807f284b40 RCX: ffff88807e661e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffff88807e661e00 R09: 0000000000000002 R10: 0000000000000011 R11: 0000000000000100 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100fe50973 skb_valid_dst include/net/dst_metadata.h:96 [inline] ip6_rcv_finish_core+0x21d/0x420 net/ipv6/ip6_input.c:65 ip6_rcv_finish+0x143/0x230 net/ipv6/ip6_input.c:77 ip_sabotage_in+0x1f4/0x280 net/bridge/br_netfilter_hooks.c:1001 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+0x21d/0x3b0 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5646 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5760 netif_receive_skb_internal net/core/dev.c:5846 [inline] netif_receive_skb+0x1bc/0x720 net/core/dev.c:5905 NF_HOOK+0x9e/0x3a0 include/linux/netfilter.h:304 br_handle_frame_finish+0x13e5/0x18f0 net/bridge/br_input.c:221 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:5540 __netif_receive_skb_one_core net/core/dev.c:5644 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5760 process_backlog+0x391/0x6f0 net/core/dev.c:6088 __napi_poll+0xc0/0x460 net/core/dev.c:6650 napi_poll net/core/dev.c:6717 [inline] net_rx_action+0x616/0xc40 net/core/dev.c:6853 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:__schedule+0x0/0x45a0 kernel/sched/core.c:6579 Code: cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa be 01 00 00 00 48 c7 c7 80 66 73 8e e8 1b f4 50 f7 c3 cc cc cc cc cc cc cc cc cc cc 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 RSP: 0018:ffffc9000bbf7958 EFLAGS: 00000286 RAX: 5810105073f2de00 RBX: ffff88807e661e00 RCX: 5810105073f2de00 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001 RBP: ffffc9000bbf7a10 R08: ffffffff8e8b14ef R09: 1ffffffff1d1629d R10: dffffc0000000000 R11: fffffbfff1d1629e R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200177ef2c 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:preempt_count_add+0x23/0x1a0 kernel/sched/core.c:5841 Code: 84 00 00 00 00 00 90 f3 0f 1e fa 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 80 c4 2c 97 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 eb 00 00 00 83 3d 6e 3d d0 15 00 75 07 65 8b 05 ad 2e RSP: 0018:ffffc9000bbf7ad8 EFLAGS: 00000a06 RAX: 0000000000000004 RBX: ffff88807e661e00 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001 RBP: ffff88807e663568 R08: ffffffff8e8b14ef R09: 1ffffffff1d1629d R10: dffffc0000000000 R11: fffffbfff1d1629e R12: ffffc9000bbf7c68 R13: ffffc90000a2c788 R14: 1ffff1100fccc3c0 R15: dffffc0000000000 schedule+0xb6/0x170 kernel/sched/core.c:6773 futex_wait_queue+0x138/0x1b0 kernel/futex/waitwake.c:355 futex_wait+0x1ec/0x5e0 kernel/futex/waitwake.c:656 do_futex+0x2ff/0x3e0 kernel/futex/syscalls.c:134 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192 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: 0033:0x7f4ba8f9c819 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:00007f4ba9e450e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f4ba9215fa8 RCX: 00007f4ba8f9c819 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f4ba9215fa8 RBP: 00007f4ba9215fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4ba9216038 R14: 00007ffeca860eb0 R15: 00007ffeca860f98 net_ratelimit: 1882 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:02:c7:c7:81:be:54, 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 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: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) net_ratelimit: 2876 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: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 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)