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): P6126/2:b..l rcu: (detected by 1, t=10502 jiffies, g=11173, q=5935 ncpus=2) task:syz.1.48 state:R running task stack:25096 pid:6126 tgid:6126 ppid:5829 task_flags:0x2040004c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256 irqentry_exit+0x36/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: 9b 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 92 d4 e9 0e 0f 82 74 02 00 00 8b 35 ea 04 ea 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 a9 9a 08 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90004fceaf0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c45a0 RCX: 00000000c639c71c RDX: 0000000000000000 RSI: ffffffff8da0240a RDI: ffffffff8bf075c0 RBP: 0000000000000002 R08: f501fefe41178ce3 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [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:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] slab_free_hook mm/slub.c:2491 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x147/0x6c0 mm/slub.c:6740 mempool_free+0x102/0x750 mm/mempool.c:576 bio_put_percpu_cache block/bio.c:805 [inline] bio_put+0x355/0x5b0 block/bio.c:824 bio_endio+0x713/0x860 block/bio.c:1672 blk_update_request+0x93e/0x15f0 block/blk-mq.c:998 blk_mq_end_request+0x4f/0x90 block/blk-mq.c:1160 blk_mq_complete_request block/blk-mq.c:1338 [inline] blk_mq_complete_request+0x8b/0xb0 block/blk-mq.c:1335 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:2837 [inline] __blk_mq_flush_list+0x9a/0xc0 block/blk-mq.c:2833 blk_mq_dispatch_queue_requests+0x184/0x7b0 block/blk-mq.c:2882 blk_mq_flush_plug_list+0x1f2/0x600 block/blk-mq.c:2970 blk_add_rq_to_plug+0x1ca/0x540 block/blk-mq.c:1399 blk_mq_submit_bio+0x1ecc/0x3380 block/blk-mq.c:3222 __submit_bio+0x3cf/0x690 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x53d/0xc10 block/blk-core.c:755 submit_bio_noacct+0x5bd/0x1f60 block/blk-core.c:879 __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:491 do_writepages+0x27a/0x600 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:379 __filemap_fdatawrite_range+0xb9/0x100 mm/filemap.c:422 filemap_write_and_wait_range mm/filemap.c:694 [inline] filemap_write_and_wait_range+0xa3/0x130 mm/filemap.c:685 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:709 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:966 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 __do_sys_exit_group kernel/exit.c:1118 [inline] __se_sys_exit_group kernel/exit.c:1116 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1116 x64_sys_call+0x150b/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f109c98efc9 RSP: 002b:00007ffc89c0b548 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f109c98efc9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc89c0b5ac R08: 0000001d89c0b63f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000000a R13: 00000000000927c0 R14: 0000000000017fc5 R15: 00007ffc89c0b600 rcu: rcu_preempt kthread starved for 4671 jiffies! g11173 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:28440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:398 [inline] RIP: 0010:__rcu_read_unlock+0x7c/0x550 kernel/rcu/tree_plugin.h:435 Code: 04 00 00 8b 9d 84 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 83 eb 01 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 <38> d0 7c 08 84 d2 0f 85 f3 01 00 00 41 89 9c 24 84 04 00 00 85 db RSP: 0018:ffffc90000006ad0 EFLAGS: 00000202 RAX: 0000000000000007 RBX: 0000000000000003 RCX: ffffc90000006ac4 RDX: 0000000000000000 RSI: ffffffff8da0240a RDI: ffffffff8e097e84 RBP: ffffffff8e097a00 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000831c8 R12: ffffffff8e097a00 R13: ffffc90000006b70 R14: ffffc90000007c70 R15: ffffc90000006ba4 FS: 0000000000000000(0000) GS:ffff888124a10000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000143f000 CR3: 000000007ee1c000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:899 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3fe/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:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kmem_cache_free+0x2d4/0x6c0 mm/slub.c:6740 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1110 __kfree_skb net/core/skbuff.c:1167 [inline] sk_skb_reason_drop+0x136/0x1a0 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ip6_mc_input+0x82c/0xf60 net/ipv6/ip6_input.c:593 dst_input include/net/dst.h:474 [inline] dst_input include/net/dst.h:472 [inline] ip6_rcv_finish+0x3df/0x580 net/ipv6/ip6_input.c:79 ip_sabotage_in+0x21e/0x290 net/bridge/br_netfilter_hooks.c:990 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x424/0x750 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:6079 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192 netif_receive_skb_internal net/core/dev.c:6278 [inline] netif_receive_skb+0x137/0x7b0 net/core/dev.c:6337 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+0x10b7/0x1ec0 net/bridge/br_input.c:235 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x76a/0xfc0 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:291 [inline] br_handle_frame+0xad8/0x14b0 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0xa25/0x4bd0 net/core/dev.c:5966 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6077 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192 process_backlog+0x439/0x15e0 net/core/dev.c:6544 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x97f/0xef0 net/core/dev.c:7784 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: b7 6f 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 a3 e4 2c 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 00000000009fc5df RBX: 0000000000000000 RCX: ffffffff8b5d42a9 RDX: 0000000000000000 RSI: ffffffff8da27d51 RDI: ffffffff8bf075c0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff908239d0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 net_ratelimit: 12730 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, 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 veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, 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 veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, 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 veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, 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:8e:d4:99:bb:fe:ce, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 11794 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, 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:8e:d4:99:bb:fe:ce, 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 veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, 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:8e:d4:99:bb:fe:ce, 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 veth0_to_bridge with own address as source address (addr:8e:d4:99:bb:fe:ce, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)