bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12310/2:b..l rcu: (detected by 1, t=10503 jiffies, g=53349, q=1227 ncpus=2) task:syz.0.1615 state:R running task stack:24312 pid:12310 tgid:12310 ppid:5806 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_release+0x183/0x2f0 kernel/locking/lockdep.c:5893 Code: 0f c1 05 38 9e 0b 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 4d 5c 0b 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc90003b2eb40 EFLAGS: 00000206 RAX: 6780fc07fcd4e200 RBX: ffffffff8e3c4460 RCX: ffffc90003b2eb4c RDX: 0000000000000001 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e3c0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000383f2 R12: ffffffff816c4914 R13: 0000000000000202 R14: ffff88803381c900 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20a0 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_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:559 slab_free_hook mm/slub.c:2484 [inline] slab_free mm/slub.c:6611 [inline] kmem_cache_free+0x15e/0x6c0 mm/slub.c:6721 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+0xbbb/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: 0033:0x7fa702f8eec9 RSP: 002b:00007fffb0b08a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa702f8eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffb0b08a9c R08: 0000001db0b08b2f R09: 00000000000927c0 R10: 0000000000043888 R11: 0000000000000246 R12: 0000000000000155 R13: 00000000000927c0 R14: 0000000000087aef R15: 00007fffb0b08af0 rcu: rcu_preempt kthread starved for 216 jiffies! g53349 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:28120 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: CPU: 1 UID: 0 PID: 12116 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: 57 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 a2 14 ea 0e 0f 82 74 02 00 00 8b 35 1a 45 ea 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 b9 56 0b 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90000a07408 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c4460 RCX: 000000003812b9d3 RDX: 0000000000000000 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e3c0 RBP: 0000000000000002 R08: e9efff99835e4d1c R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124ad9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9a55fb12f8 CR3: 000000007376e000 CR4: 00000000003526f0 Call Trace: 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 __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:2523 [inline] slab_free mm/slub.c:6611 [inline] kmem_cache_free+0x2d4/0x6c0 mm/slub.c:6721 __skb_ext_put+0x102/0x2c0 net/core/skbuff.c:7160 skb_ext_put include/linux/skbuff.h:4944 [inline] skb_ext_put include/linux/skbuff.h:4941 [inline] skb_release_head_state+0x1c2/0x290 net/core/skbuff.c:1144 skb_release_all net/core/skbuff.c:1150 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb net/core/skbuff.c:1398 [inline] consume_skb+0x85/0x100 net/core/skbuff.c:1392 dummy_xmit+0x154/0x1c0 drivers/net/dummy.c:65 __netdev_start_xmit include/linux/netdevice.h:5248 [inline] netdev_start_xmit include/linux/netdevice.h:5257 [inline] xmit_one net/core/dev.c:3845 [inline] dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3861 __dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4763 dev_queue_xmit include/linux/netdevice.h:3365 [inline] br_dev_queue_push_xmit+0x272/0x8a0 net/bridge/br_forward.c:53 br_nf_dev_queue_xmit+0x6e0/0x2b20 net/bridge/br_netfilter_hooks.c:920 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_post_routing+0x8e7/0x1190 net/bridge/br_netfilter_hooks.c:966 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook+0x45e/0x780 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] br_forward_finish+0xcd/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167 br_nf_forward_finish+0x66a/0xba0 net/bridge/br_netfilter_hooks.c:662 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_forward_ip.part.0+0x609/0x810 net/bridge/br_netfilter_hooks.c:716 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:676 [inline] br_nf_forward+0xf0f/0x1be0 net/bridge/br_netfilter_hooks.c:773 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook+0x45e/0x780 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xf1/0x180 net/bridge/br_forward.c:191 br_flood+0x17c/0x650 net/bridge/br_forward.c:238 br_handle_frame_finish+0x10e6/0x1ec0 net/bridge/br_input.c:229 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:523 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:510 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:835 [inline] nsim_dev_trap_report_work+0x8b5/0xcf0 drivers/net/netdevsim/dev.c:866 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 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 net_ratelimit: 2 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) net_ratelimit: 6 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:5e:b7:0e:11:4d:36, vlan:0)