bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5992/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9413, q=2665 ncpus=2) task:syz.2.13 state:R running task stack:25512 pid:5992 tgid:5991 ppid:5864 task_flags:0x20400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__call_rcu_common.constprop.0+0x400/0xa10 kernel/rcu/tree.c:3149 Code: 05 95 31 bb 0c 48 03 83 20 01 00 00 49 39 c5 0f 8f e8 02 00 00 e8 90 67 21 00 9c 58 f6 c4 02 0f 85 9b 02 00 00 fb 48 83 c4 18 <5b> 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc be 04 00 00 00 48 c7 RSP: 0018:ffffc900044ef018 EFLAGS: 00000286 RAX: 0000000000000046 RBX: ffff8880b843b440 RCX: ffffffff81c2f26f RDX: 0000000000000000 RSI: ffffffff8c162c80 RDI: ffffffff81a18be0 RBP: ffff88802fe67180 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff90ab7697 R11: 0000000000000001 R12: ffff8880b843b560 R13: 000000000000034b R14: ffff8880b843b530 R15: ffff8880b843b4e8 slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x16d/0x4d0 mm/slub.c:4782 mempool_free+0x102/0x750 mm/mempool.c:576 bio_put_percpu_cache block/bio.c:801 [inline] bio_put+0x355/0x5b0 block/bio.c:820 bio_endio+0x70a/0x850 block/bio.c:1651 blk_update_request+0x93e/0x15f0 block/blk-mq.c:989 blk_mq_end_request+0x5b/0x630 block/blk-mq.c:1151 blk_mq_complete_request block/blk-mq.c:1329 [inline] blk_mq_complete_request+0x88/0xb0 block/blk-mq.c:1326 nullb_complete_cmd drivers/block/null_blk/main.c:1402 [inline] null_handle_cmd drivers/block/null_blk/main.c:1454 [inline] null_queue_rq+0xb69/0xfd0 drivers/block/null_blk/main.c:1693 null_queue_rqs+0xe9/0x2f0 drivers/block/null_blk/main.c:1707 __blk_mq_flush_list block/blk-mq.c:2828 [inline] __blk_mq_flush_list+0x97/0xc0 block/blk-mq.c:2824 blk_mq_dispatch_queue_requests+0x184/0x7b0 block/blk-mq.c:2873 blk_mq_flush_plug_list+0x1f2/0x600 block/blk-mq.c:2961 blk_add_rq_to_plug+0x1ca/0x540 block/blk-mq.c:1390 blk_mq_submit_bio+0x1a1c/0x2880 block/blk-mq.c:3212 __submit_bio+0x3cf/0x690 block/blk-core.c:635 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0xb49/0x1eb0 block/blk-core.c:874 __block_write_full_folio+0x735/0xe00 fs/buffer.c:1933 block_write_full_folio+0x341/0x400 fs/buffer.c:2753 blkdev_writepages+0xb8/0x140 block/fops.c:483 do_writepages+0x27a/0x600 mm/page-writeback.c:2634 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:376 __filemap_fdatawrite_range+0xb9/0x100 mm/filemap.c:419 filemap_write_and_wait_range mm/filemap.c:691 [inline] filemap_write_and_wait_range+0xa3/0x130 mm/filemap.c:682 filemap_write_and_wait include/linux/pagemap.h:68 [inline] sync_blockdev block/bdev.c:260 [inline] sync_blockdev block/bdev.c:256 [inline] bdev_release+0x4d3/0x6d0 block/bdev.c:1126 blkdev_release+0x15/0x20 block/fops.c:699 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f091d98ebe9 RSP: 002b:00007f091e829038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f091dbb5fa0 RCX: 00007f091d98ebe9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000002 RBP: 00007f091da11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f091dbb6038 R14: 00007f091dbb5fa0 R15: 00007ffc65ef3818 rcu: rcu_preempt kthread starved for 6352 jiffies! g9413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27888 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:lock_acquire+0x19/0x350 kernel/locking/lockdep.c:5828 Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 4d 89 cf 41 56 41 89 f6 41 55 41 89 d5 41 54 45 89 c4 55 <89> cd 53 48 89 fb 48 83 ec 38 65 48 8b 05 7d 5f 3e 12 48 89 44 24 RSP: 0018:ffffc90000a07a70 EFLAGS: 00000246 RAX: ffffffff816ab56d RBX: 0000000000000001 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e5c1060 RBP: ffffc90000a07b60 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000a07b18 R11: 00000000000a90a2 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881247c4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f091e808990 CR3: 0000000077e6e000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4782 __skb_ext_put+0x102/0x2c0 net/core/skbuff.c:7153 skb_ext_put include/linux/skbuff.h:4892 [inline] skb_ext_put include/linux/skbuff.h:4889 [inline] skb_release_head_state+0x1c2/0x290 net/core/skbuff.c:1143 skb_release_all net/core/skbuff.c:1149 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] sk_skb_reason_drop+0xeb/0x1a0 net/core/skbuff.c:1203 kfree_skb_reason include/linux/skbuff.h:1275 [inline] kfree_skb include/linux/skbuff.h:1284 [inline] ip6_mc_input+0x774/0xeb0 net/ipv6/ip6_input.c:593 dst_input include/net/dst.h:471 [inline] dst_input include/net/dst.h:469 [inline] ip6_rcv_finish+0x3df/0x580 net/ipv6/ip6_input.c:79 ip_sabotage_in+0x21b/0x290 net/bridge/br_netfilter_hooks.c:993 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ipv6_rcv+0xa4/0x650 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 netif_receive_skb_internal net/core/dev.c:6178 [inline] netif_receive_skb+0x137/0x7b0 net/core/dev.c:6237 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_pass_frame_up+0x346/0x490 net/bridge/br_input.c:70 br_handle_frame_finish+0xf5a/0x1ca0 net/bridge/br_input.c:227 br_nf_hook_thresh+0x304/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0xad8/0x14b0 net/bridge/br_input.c:434 __netif_receive_skb_core.constprop.0+0xa25/0x48c0 net/core/dev.c:5866 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5977 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 process_backlog+0x442/0x15e0 net/core/dev.c:6444 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494 napi_poll net/core/dev.c:7557 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 0c 65 02 c3 cc cc cc cc 0f 1f 00 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 63 81 19 00 fb f4 3c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000000033e34 RBX: 0000000000000001 RCX: ffffffff8b908bf9 RDX: ffffed10170a6656 RSI: ffffffff8c162c80 RDI: ffffffff8190cca1 RBP: ffffed1003c55b40 R08: 0000000000000000 R09: ffffed10170a6655 R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e2ada00 R14: ffffffff90ab7690 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 net_ratelimit: 16205 callbacks suppressed 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:ba:48:43:1e:df:cf, 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 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)