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): P24928/1:b..l rcu: (detected by 1, t=10503 jiffies, g=137045, q=1959 ncpus=2) task:syz.4.5040 state:R running task stack:24936 pid:24928 tgid:24920 ppid:17736 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: ec 97 11 00 00 00 00 eb b5 e8 55 5c 07 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 45 a7 97 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 62 4d 92 RSP: 0018:ffffc9000e3671e0 EFLAGS: 00000282 RAX: aa3ff170296a0000 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000004 RSI: ffffffff8e22040c RDI: ffffffff8c28b660 RBP: ffff888032e18c30 R08: ffffc9000e367e90 R09: 0000000000000000 R10: ffffc9000e367338 R11: fffff52001c6ce69 R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff8e95cca0 R15: ffff888032e18000 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1bba/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 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5612 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_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6832 allocate_hook_entries_size net/netfilter/core.c:54 [inline] __nf_hook_entries_try_shrink+0x328/0x700 net/netfilter/core.c:253 __nf_unregister_net_hook+0x4cc/0x6f0 net/netfilter/core.c:513 nf_unregister_net_hook net/netfilter/core.c:-1 [inline] nf_unregister_net_hooks+0xcb/0x140 net/netfilter/core.c:606 nf_defrag_ipv4_disable+0x95/0xe0 net/ipv4/netfilter/nf_defrag_ipv4.c:177 nf_ct_netns_do_put net/netfilter/nf_conntrack_proto.c:531 [inline] nf_ct_netns_put+0x3c1/0x520 net/netfilter/nf_conntrack_proto.c:614 cleanup_match net/ipv4/netfilter/ip_tables.c:459 [inline] find_check_entry net/ipv4/netfilter/ip_tables.c:563 [inline] translate_table+0x1a72/0x2110 net/ipv4/netfilter/ip_tables.c:716 do_replace net/ipv4/netfilter/ip_tables.c:1137 [inline] do_ipt_set_ctl+0x9f5/0xe00 net/ipv4/netfilter/ip_tables.c:1635 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2381 __sys_setsockopt net/socket.c:2406 [inline] __do_sys_setsockopt net/socket.c:2412 [inline] __se_sys_setsockopt net/socket.c:2409 [inline] __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2409 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1ed799ce59 RSP: 002b:00007f1ed8774028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f1ed7c16090 RCX: 00007f1ed799ce59 RDX: 0000000000000040 RSI: 0004000000000000 RDI: 0000000000000004 RBP: 00007f1ed7a32d6f R08: 0000000000000448 R09: 0000000000000000 R10: 0000200000000b40 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ed7c16128 R14: 00007f1ed7c16090 R15: 00007ffe7eb62388 rcu: rcu_preempt kthread starved for 2992 jiffies! g137045 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x389/0x470 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: 5738 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events ovs_dp_masks_rebalance RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5598 [inline] RIP: 0010:lock_is_held_type+0x8d/0x150 kernel/locking/lockdep.c:5940 Code: bd 88 0b 00 00 00 7e 48 4c 89 eb 48 81 c3 90 0b 00 00 45 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 f7 01 00 00 85 c0 75 2a <49> ff c7 49 63 85 88 0b 00 00 48 83 c3 28 49 39 c7 7c d8 eb 11 48 RSP: 0018:ffffc90000006c48 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88801ff22aa0 RCX: 0000000080000101 RDX: ffff88801ff21ec0 RSI: ffffffff8e95cca0 RDI: ffff88801ff22aa0 RBP: 00000000ffffffff R08: ffffffff8a85854e R09: ffffffff8e95cca0 R10: 0000000000000003 R11: ffffffff8a85d190 R12: 0000000000000246 R13: ffff88801ff21ec0 R14: ffffffff8e95cca0 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888125287000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555570f684e8 CR3: 000000007e10e000 CR4: 00000000003526f0 Call Trace: net_generic+0x101/0x240 include/net/netns/generic.h:46 is_pppoe_ip net/bridge/br_netfilter_hooks.c:123 [inline] br_nf_post_routing+0x4fa/0xfe0 net/bridge/br_netfilter_hooks.c:945 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+0x23e/0x3f0 include/linux/netfilter.h:316 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+0xa5e/0xe90 net/bridge/br_netfilter_hooks.c:667 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_forward_ip+0x7ef/0xa30 net/bridge/br_netfilter_hooks.c:721 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+0x23e/0x3f0 include/linux/netfilter.h:316 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_handle_frame_finish+0x1521/0x1c80 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+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 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+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6089 __netif_receive_skb_one_core net/core/dev.c:6200 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6666 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/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:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 2d 6b f6 f5 f7 c3 00 02 00 00 74 05 e8 50 02 22 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e4 e9 e7 f5 65 8b 05 0d a0 8d 07 85 c0 74 18 5b 41 5e c3 cc cc RSP: 0018:ffffc90004a3f760 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000286 RCX: 0000000080000001 RDX: 0000000000000007 RSI: ffffffff8dface83 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff9030d4f7 R09: 1ffffffff2061a9e R10: dffffc0000000000 R11: fffffbfff2061a9f R12: ffff888073aa0000 R13: ffff888073a98000 R14: ffffffff9a711cb8 R15: 0000000000000003 __debug_check_no_obj_freed lib/debugobjects.c:1125 [inline] debug_check_no_obj_freed+0x52e/0x550 lib/debugobjects.c:1146 __free_pages_prepare mm/page_alloc.c:1409 [inline] __free_frozen_pages+0x593/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5612 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:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_noprof+0x316/0x760 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] ovs_flow_masks_rebalance+0xf9/0xc30 net/openvswitch/flow_table.c:1112 ovs_dp_masks_rebalance+0x56/0xe0 net/openvswitch/datapath.c:2593 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 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 net_ratelimit: 12329 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 14048 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)