bridge0: received packet on veth0_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): P20248/2:b..l rcu: (detected by 1, t=10503 jiffies, g=118921, q=2223 ncpus=2) task:syz.0.2940 state:R running task stack:25272 pid:20248 tgid:20246 ppid:19543 task_flags:0x2040054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_release+0x85/0x3c0 kernel/locking/lockdep.c:5882 Code: 84 1c 02 00 00 65 8b 05 c9 50 ca 11 85 c0 0f 85 0d 02 00 00 65 4c 8b 3d d1 0b ca 11 41 83 bf 9c 0b 00 00 00 0f 85 f7 01 00 00 <49> 81 3e 20 25 30 94 0f 84 ea 01 00 00 9c 5b fa 48 c7 c7 2b 3f 24 RSP: 0018:ffffc9000422e898 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000422e9b8 RCX: 0000000080000001 RDX: ffffc9000422e901 RSI: ffffffff8c4bd260 RDI: ffffffff8c4bd220 RBP: 1ffffffff224a201 R08: ffffc9000422f600 R09: 0000000000000000 R10: ffffc9000422e9f8 R11: fffff52000845d41 R12: ffffc90004228000 R13: ffffffff8176f21f R14: ffffffff8eb59c20 R15: ffff8880347f9f00 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 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:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x165/0x610 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:236 [inline] __call_rcu_common kernel/rcu/tree.c:3144 [inline] call_rcu+0x43/0x8b0 kernel/rcu/tree.c:3279 slab_free_hook mm/slub.c:2669 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x462/0x650 mm/slub.c:6532 mempool_free+0xec/0x130 mm/mempool.c:704 bio_endio_bh fs/buffer.c:151 [inline] bh_end_async_write+0x99/0x3b0 fs/buffer.c:430 blk_update_request+0x57b/0xe50 block/blk-mq.c:1016 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1147 nullb_complete_cmd drivers/block/null_blk/main.c:1412 [inline] null_handle_cmd drivers/block/null_blk/main.c:1464 [inline] null_queue_rq+0xc2a/0xe70 drivers/block/null_blk/main.c:1703 null_queue_rqs+0x158/0x260 drivers/block/null_blk/main.c:1717 __blk_mq_flush_list block/blk-mq.c:2827 [inline] blk_mq_dispatch_queue_requests+0x426/0x800 block/blk-mq.c:2872 blk_mq_flush_plug_list+0x428/0x540 block/blk-mq.c:2960 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1266 blk_finish_plug+0x5d/0x80 block/blk-core.c:1293 blkdev_writepages+0x12c/0x1b0 block/fops.c:486 do_writepages+0x338/0x560 mm/page-writeback.c:2571 filemap_writeback mm/filemap.c:387 [inline] filemap_fdatawrite_range mm/filemap.c:412 [inline] filemap_write_and_wait_range+0x335/0x3f0 mm/filemap.c:684 filemap_write_and_wait include/linux/pagemap.h:65 [inline] sync_blockdev block/bdev.c:276 [inline] bdev_release+0x1a0/0x690 block/bdev.c:1129 blkdev_release+0x15/0x20 block/fops.c:680 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3038 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+0x104/0x730 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:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1e9719de59 RSP: 002b:00007f1e97fd8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000008 RBX: 00007f1e97425fa0 RCX: 00007f1e9719de59 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000007 RBP: 00007f1e97233e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1e97426038 R14: 00007f1e97425fa0 R15: 00007f1e9754fa48 rcu: rcu_preempt kthread starved for 525 jiffies! g118921 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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:unwind_next_frame+0xd09/0x2550 arch/x86/kernel/unwind_orc.c:645 Code: 18 74 08 48 89 df e8 c6 f8 bc 00 48 8b 04 24 48 89 03 ba 10 00 00 00 49 8d 5e 50 48 89 df 31 f6 e8 8c fa bc 00 48 8b 54 24 08 c7 04 00 00 48 89 5c 24 48 49 8d 7e 08 48 89 fb 48 c1 eb 03 42 RSP: 0018:ffffc90000006a60 EFLAGS: 00000246 RAX: ffffc90000006b58 RBX: ffffc90000006b58 RCX: 0000000000000000 RDX: ffffffff91777de8 RSI: 0000000000000000 RDI: ffffc90000006b68 RBP: 1ffffffff22eefbd R08: ffffc90000006b67 R09: 0000000000000000 R10: ffffc90000006b58 R11: fffff52000000d6d R12: dffffc0000000000 R13: ffffffff91777de4 R14: ffffc90000006b08 R15: ffffc90000006b50 FS: 0000000000000000(0000) GS:ffff888124f5a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000325030 CR3: 000000007c942000 CR4: 00000000003526f0 Call Trace: 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 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6532 skb_ext_reset include/linux/skbuff.h:5117 [inline] skb_release_head_state+0x270/0x360 net/core/skbuff.c:1183 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x24/0x210 net/core/skbuff.c:1205 kfree_skb_reason include/linux/skbuff.h:1323 [inline] kfree_skb include/linux/skbuff.h:1332 [inline] ip6_mc_input+0x909/0xbc0 net/ipv6/ip6_input.c:638 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] netif_receive_skb_internal net/core/dev.c:6405 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6464 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x1192/0x1990 net/bridge/br_input.c:-1 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:318 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [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+0x989/0x30b0 net/core/dev.c:6093 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6670 __napi_poll+0xaa/0x330 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7949 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 3c 81 02 e9 13 05 03 00 cc cc cc 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 f3 29 1b 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e807de0 EFLAGS: 00000246 RAX: 0000000000ca7dcf RBX: ffffffff819ab25c RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8e22949e RDI: ffffffff8c4bd280 RBP: ffffffff8e807eb8 R08: ffff8880b86338db R09: 1ffff110170c671b R10: dffffc0000000000 R11: ffffed10170c671c R12: 0000000000000000 R13: 1ffffffff1d11de8 R14: 1ffffffff1d00fc4 R15: dffffc0000000000 arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x1cc/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 rest_init+0x2de/0x300 init/main.c:717 start_kernel+0x392/0x3e0 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x157 net_ratelimit: 15864 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:ce:59:c0:d2:6a:ca, 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 veth0_to_bridge with own address as source address (addr:ce:59:c0:d2:6a:ca, 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:ce:59:c0:d2:6a:ca, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)