bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P30056/1:b..l.. rcu: (detected by 1, t=10509 jiffies, g=146417, q=2702 ncpus=2) task:syz.0.6184 state:R running task stack:25576 pid:30056 tgid:30056 ppid:28073 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5820 kernel/sched/core.c:7382 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline] irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947 Code: ff ff ff e8 e0 ca 50 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 e2 d4 f7 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 7f d2 53 0a cc 48 8d 3d c7 d3 db RSP: 0018:ffffc90002e6eea0 EFLAGS: 00000296 RAX: 426673dc1772b000 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000ceaf9763 RSI: ffffffff8e70fdbc RDI: ffffffff8c6e1780 RBP: ffff888084445dc0 R08: ffffffff8178699f R09: 0000000000000000 R10: ffffc90002e6efd8 R11: ffffffff81b301f0 R12: ffffffff8fd59ca0 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:351 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:377 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_noprof+0x2b4/0x600 mm/slub.c:5010 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x163/0x610 lib/debugobjects.c:420 debug_objects_fill_pool lib/debugobjects.c:780 [inline] debug_object_activate+0x38d/0x420 lib/debugobjects.c:869 debug_rcu_head_queue kernel/rcu/rcu.h:245 [inline] rcu_do_enqueue+0x2a/0x870 kernel/rcu/tree.c:3164 __call_rcu_common kernel/rcu/tree.c:3300 [inline] call_rcu+0x20e/0x300 kernel/rcu/tree.c:3395 __slab_free+0x274/0x2c0 mm/slub.c:5823 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kvmalloc_node_noprof+0x49a/0x820 mm/slub.c:7015 futex_hash_allocate+0x48f/0xe70 kernel/futex/core.c:1885 copy_process+0x29d8/0x44b0 kernel/fork.c:2444 kernel_clone+0x2d7/0x940 kernel/fork.c:2785 __do_sys_clone3 kernel/fork.c:3088 [inline] __se_sys_clone3+0x33c/0x360 kernel/fork.c:3067 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f78ce7a0349 RSP: 002b:00007fff194dc428 EFLAGS: 00000202 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007f78ce75b8e0 RCX: 00007f78ce7a0349 RDX: 00007f78ce75b8e0 RSI: 0000000000000058 RDI: 00007fff194dc480 RBP: 00007f78cf6f46c0 R08: 00007f78cf6f46c0 R09: 00007fff194dc567 R10: 0000000000000008 R11: 0000000000000202 R12: ffffffffffffffe8 R13: 000000000000000b R14: 00007fff194dc480 R15: 00007fff194dc568 rcu: rcu_preempt kthread starved for 3335 jiffies! g146417 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27696 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5820 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: CPU: 1 UID: 0 PID: 8321 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__ipv6_prefix_equal64_half include/net/ipv6.h:607 [inline] RIP: 0010:ipv6_prefix_equal include/net/ipv6.h:624 [inline] RIP: 0010:fib6_node_lookup_1+0x544/0x8b0 net/ipv6/ip6_fib.c:1654 Code: f7 e9 a2 01 00 00 31 ff 44 89 f6 e8 36 f5 28 f7 4d 85 f6 0f 84 b8 00 00 00 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 be e7 99 f7 4c 8b 7d 00 4c 89 e0 48 RSP: 0018:ffffc90000a083b8 EFLAGS: 00000a06 RAX: 1ffff1100ad6930a RBX: ffff888036378500 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffff888056b49850 R08: 0000000000000100 R09: 0000000000000000 R10: ffffc90000a08480 R11: fffff52000141092 R12: ffffc90000a089a8 R13: ffffc90000a08460 R14: 0000000000000008 R15: ffffc90000a08468 FS: 0000000000000000(0000) GS:ffff888123b6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555562674e8 CR3: 000000000fb48000 CR4: 00000000003526f0 Call Trace: fib6_node_lookup+0xe4/0x1d0 net/ipv6/ip6_fib.c:1702 fib6_table_lookup+0xbc/0xae0 net/ipv6/route.c:2229 ip6_pol_route+0x229/0x14d0 net/ipv6/route.c:2270 pol_lookup_func include/net/ip6_fib.h:672 [inline] fib6_rule_lookup+0x512/0x6e0 net/ipv6/fib6_rules.c:123 ip6_route_input_lookup net/ipv6/route.c:2341 [inline] ip6_route_input+0x78d/0xb20 net/ipv6/route.c:2644 ip6_rcv_finish+0x141/0x280 net/ipv6/ip6_input.c:117 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325 __netif_receive_skb_one_core net/core/dev.c:6405 [inline] __netif_receive_skb net/core/dev.c:6518 [inline] process_backlog+0x795/0x18b0 net/core/dev.c:6869 __napi_poll+0xaa/0x330 net/core/dev.c:7938 napi_poll net/core/dev.c:8001 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8158 handle_softirqs+0x265/0x8d0 kernel/softirq.c:669 do_softirq+0x77/0xd0 kernel/softirq.c:569 __local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1b1/0x7a0 net/core/skbuff.c:700 alloc_skb include/linux/skbuff.h:1390 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline] nsim_dev_trap_report_work+0x25f/0xb30 drivers/net/netdevsim/dev.c:847 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 15209 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)