bridge0: received packet on bridge_slave_1 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): P20559/1:b..l.. rcu: (detected by 1, t=10513 jiffies, g=98265, q=2478 ncpus=2) task:syz.3.3616 state:R running task stack:23968 pid:20559 tgid:20556 ppid:18807 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 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:__asan_memset+0x22/0x50 mm/kasan/shadow.c:84 Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 1e e5 ff ff <84> c0 74 11 4c 89 f7 89 ee 48 89 da 5b 41 5e 5d e9 29 e8 c2 09 31 RSP: 0018:ffffc900045bf2c0 EFLAGS: 00000256 RAX: ffffc900045bfd01 RBX: 0000000000000010 RCX: ffffffff81788644 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900045bf3d8 RBP: 0000000000000000 R08: ffffc900045bf3e7 R09: 1ffff920008b7e7c R10: dffffc0000000000 R11: fffff520008b7e7d R12: dffffc0000000000 R13: ffffffff92c19bec R14: ffffc900045bf3d8 R15: ffffc900045bf3d0 unwind_next_frame+0xd04/0x2550 arch/x86/kernel/unwind_orc.c:621 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:183 __reset_page_owner+0x73/0x2a0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1403 [inline] __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2954 __slab_free+0x269/0x2c0 mm/slub.c:5926 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:4720 [inline] slab_alloc_node mm/slub.c:5033 [inline] kmem_cache_alloc_node_noprof+0x34f/0x600 mm/slub.c:5105 kmalloc_reserve net/core/skbuff.c:616 [inline] __alloc_skb+0x27a/0x7a0 net/core/skbuff.c:716 netlink_sendmsg+0x5cd/0xb20 net/netlink/af_netlink.c:1895 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2715 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769 __sys_sendmsg net/socket.c:2801 [inline] __do_sys_sendmsg net/socket.c:2806 [inline] __se_sys_sendmsg net/socket.c:2804 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804 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: 0033:0x7f48ca19fb19 RSP: 002b:00007f48cb0e7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f48ca425fa0 RCX: 00007f48ca19fb19 RDX: 0000000004000000 RSI: 0000200000000200 RDI: 0000000000000003 RBP: 00007f48ca237b70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f48ca426038 R14: 00007f48ca425fa0 R15: 00007ffdb5499218 rcu: rcu_preempt kthread starved for 423 jiffies! g98265 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 42 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_wait_context kernel/locking/lockdep.c:4921 [inline] RIP: 0010:__lock_acquire+0x598/0x2de0 kernel/locking/lockdep.c:5238 Code: 00 00 4c 63 fb 4b 8d 04 bf 49 8d 1c c6 48 81 c3 d0 0b 00 00 eb 1d 44 89 e0 49 ff c7 49 63 8e a0 0b 00 00 48 83 c3 28 41 89 c4 <49> 39 cf 0f 8d c5 00 00 00 49 83 ff 31 0f 83 84 00 00 00 48 8b 03 RSP: 0018:ffffc90000006a98 EFLAGS: 00000086 RAX: 0000000000000003 RBX: ffff88801f6f2bd8 RCX: 0000000000000006 RDX: 0000000000000003 RSI: 0000000000000003 RDI: 7100000000000000 RBP: ffff88801f6f2be0 R08: ffffffff817879cf R09: 0000000000000000 R10: ffffc90000006d78 R11: ffffffff81b3a880 R12: 0000000000000003 R13: 0000000000000000 R14: ffff88801f6f1f40 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff88812361f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558c7d64e8 CR3: 0000000061dc8000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 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:4720 [inline] slab_alloc_node mm/slub.c:5033 [inline] kmem_cache_alloc_noprof+0x2b4/0x600 mm/slub.c:5047 skb_ext_maybe_cow net/core/skbuff.c:7269 [inline] skb_ext_add+0x1b6/0x8e0 net/core/skbuff.c:7344 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:171 [inline] br_nf_forward_ip+0xc3/0xa30 net/bridge/br_netfilter_hooks.c:687 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:633 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323 __br_forward+0x41e/0x5d0 net/bridge/br_forward.c:130 br_flood+0x402/0x650 net/bridge/br_forward.c:352 br_handle_frame_finish+0x11fc/0x1ae0 net/bridge/br_input.c:231 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:325 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_bridge_pre net/bridge/br_input.c:293 [inline] br_handle_frame+0x1329/0x1600 net/bridge/br_input.c:453 __netif_receive_skb_core+0x989/0x30f0 net/core/dev.c:6312 __netif_receive_skb_one_core net/core/dev.c:6431 [inline] __netif_receive_skb net/core/dev.c:6546 [inline] process_backlog+0x727/0x18b0 net/core/dev.c:6897 __napi_poll+0xaa/0x330 net/core/dev.c:7977 napi_poll net/core/dev.c:8040 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8197 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 spin_unlock_bh include/linux/spinlock.h:407 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:816 [inline] nsim_dev_trap_report_work+0x7a4/0xb30 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