bridge0: received packet on veth1_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): P4786/1:b..l rcu: (detected by 0, t=10684 jiffies, g=192109, q=1514 ncpus=2) task:syz.3.7824 state:R running task stack:24360 pid:4786 tgid:4786 ppid:30875 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7270 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7592 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5913 Code: ff ff ff e8 20 29 41 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 72 54 f1 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 cf 2c 44 0a cc 48 8d 3d f7 34 da RSP: 0018:ffffc9000553f400 EFLAGS: 00000296 RAX: f2ca5ef036becc00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000acb1bb44 RSI: ffffffff8e6fd63b RDI: ffffffff8c6d9480 RBP: ffff888035c05dc0 R08: 4b00000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: ffffffff8ed5c6e0 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 save_stack+0x122/0x230 mm/page_owner.c:183 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962 __slab_free+0x274/0x2c0 mm/slub.c:5815 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:350 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+0x2b9/0x600 mm/slub.c:5010 taskstats_tgid_alloc kernel/taskstats.c:563 [inline] taskstats_exit+0x19e/0xe10 kernel/taskstats.c:602 do_exit+0x6ad/0x2360 kernel/exit.c:978 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 get_signal+0x121b/0x12c0 kernel/signal.c:3039 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0b0d19e159 RSP: 002b:00007ffdc7fb5568 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffff92 RBX: 00000000000e944a RCX: 00007f0b0d19e159 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0b0d42645c RBP: 0000000000000226 R08: 3fffffffffffffff R09: 0000000000000000 R10: 00007ffdc7fb5670 R11: 0000000000000246 R12: 00007ffdc7fb5690 R13: 00007f0b0d42645c R14: 00000000000e9670 R15: 00007ffdc7fb5670 rcu: rcu_preempt kthread starved for 6428 jiffies! g192109 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:26848 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1972 Comm: kworker/u8:17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:222 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:233 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4895 [inline] RIP: 0010:__lock_acquire+0x543/0x2e50 kernel/locking/lockdep.c:5204 Code: c7 48 63 8f a0 0b 00 00 48 83 c3 28 41 89 c4 49 39 cf 0f 8d cf 00 00 00 49 83 ff 31 0f 83 8c 00 00 00 48 8b 03 25 ff 1f 00 00 <48> 0f a3 05 95 02 f7 12 73 10 48 69 c0 c8 00 00 00 48 8d 88 d0 24 RSP: 0018:ffffc90000a17b70 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffff8880a3320c70 RCX: 0000000000000006 RDX: 0000000000000003 RSI: 0000000000000003 RDI: ffff8880a3320000 RBP: 0000000000000001 R08: 4400000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: 0000000000000003 R13: 0000000000000000 R14: ffff8880a3320ca0 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888124dd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0b0dfbfff8 CR3: 000000002a0ba000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] net_generic+0x3a/0x240 include/net/netns/generic.h:45 is_pppoe_ip net/bridge/br_netfilter_hooks.c:123 [inline] br_nf_post_routing+0x47d/0xee0 net/bridge/br_netfilter_hooks.c:945 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1165 [inline] br_nf_forward_finish+0xa76/0xea0 net/bridge/br_netfilter_hooks.c:667 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:325 br_nf_forward_ip+0x7eb/0xa30 net/bridge/br_netfilter_hooks.c:721 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_handle_frame_finish+0x1119/0x1950 net/bridge/br_input.c:229 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:291 [inline] br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x989/0x30c0 net/core/dev.c:6151 __netif_receive_skb_one_core net/core/dev.c:6262 [inline] __netif_receive_skb net/core/dev.c:6377 [inline] process_backlog+0x727/0x18b0 net/core/dev.c:6728 __napi_poll+0xaa/0x330 net/core/dev.c:7787 napi_poll net/core/dev.c:7850 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8007 handle_softirqs+0x226/0x860 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:native_irq_enable arch/x86/include/asm/irqflags.h:-1 [inline] RIP: 0010:arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline] RIP: 0010:raw_spin_rq_unlock_irq kernel/sched/sched.h:1698 [inline] RIP: 0010:__schedule+0x1dc9/0x58f0 kernel/sched/core.c:7275 Code: 31 f6 e8 6a ba b0 f5 4c 89 ff e8 32 c9 b1 f5 0f 1f 44 00 00 49 83 c7 48 4c 89 ff e8 a1 c3 01 00 e8 7c c6 ea f5 fb 4c 8b 24 24 15 fa ff ff 90 0f 0b 90 f7 c6 01 01 00 00 0f 85 ff e7 ff ff e9 RSP: 0018:ffffc90004a7f780 EFLAGS: 00000206 RAX: 00000000000a64db RBX: 1ffff9200094ff14 RCX: 8000000000000001 RDX: 0000000000000006 RSI: ffffffff8e474b17 RDI: ffffffff8c6d9480 RBP: ffffc90004a7f980 R08: ffffffff907a177f R09: 1ffffffff20f42ef R10: dffffc0000000000 R11: fffffbfff20f42f0 R12: ffff8880a3320000 R13: dffffc0000000000 R14: ffff8880a3320000 R15: ffff8880b873bb08 preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7449 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:201 [inline] _raw_spin_unlock+0x41/0x50 kernel/locking/spinlock.c:213 spin_unlock include/linux/spinlock.h:401 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report_work+0xa4b/0xb40 drivers/net/netdevsim/dev.c:847 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 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