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): P19121/1:b..l rcu: (detected by 1, t=10503 jiffies, g=73825, q=1989 ncpus=2) task:syz.3.3561 state:R running task stack:25688 pid:19121 tgid:19120 ppid:18007 task_flags:0x40054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872 Code: e9 30 ff ff ff e8 75 26 0d 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 f1 b3 7a 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 56 0c 10 0a cc 48 8d 3d 2e 6c 73 RSP: 0018:ffffc9000d0bf258 EFLAGS: 00000282 RAX: 57ee3a0a2b129000 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 00000000a69b4a9e RSI: ffffffff8e168b06 RDI: ffffffff8c27c200 RBP: 0000000000000000 R08: ffffffff81767e95 R09: ffffffff8e75e520 R10: ffffc9000d0bf3b8 R11: ffffffff81b0c260 R12: 0000000000000002 R13: ffffffff8e75e520 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 slab_free_hook mm/slub.c:2649 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x439/0x630 mm/slub.c:6295 tear_down_vmas+0x312/0x520 mm/mmap.c:1264 exit_mmap+0x4b6/0xa10 mm/mmap.c:1322 __mmput+0x118/0x430 kernel/fork.c:1175 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x6a2/0x23c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbd1879c799 RSP: 002b:00007fbd196d2028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: fffffffffffffe00 RBX: 00007fbd18a15fa0 RCX: 00007fbd1879c799 RDX: 0000000020000811 RSI: 0000200000000fc0 RDI: 0000000000000005 RBP: 00007fbd18832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbd18a16038 R14: 00007fbd18a15fa0 R15: 00007fffa8ba8c88 rcu: rcu_preempt kthread starved for 295 jiffies! g73825 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:27616 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 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+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 15972 Comm: kworker/u8:41 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: krds_cp_wq#13/0 rds_connect_worker RIP: 0010:stack_trace_consume_entry+0xf3/0x280 kernel/stacktrace.c:93 Code: 8b 74 24 08 48 8b 1f 45 8d 79 01 0f b6 44 15 00 84 c0 0f 85 3a 01 00 00 45 89 38 4e 8d 3c cb 4c 89 f8 48 c1 e8 03 80 3c 10 00 <74> 1a 4c 89 ff 48 89 f3 49 89 d4 4c 89 c5 e8 ba 20 7f 00 49 89 e8 RSP: 0018:ffffc90000006bb8 EFLAGS: 00000246 RAX: 1ffff92000000db7 RBX: ffffc90000006d50 RCX: 0000000080000100 RDX: dffffc0000000000 RSI: ffffffff8a794497 RDI: ffffc90000006cc0 RBP: 1ffff92000000d9a R08: ffffc90000006cd0 R09: 000000000000000d R10: ffffc90000006c58 R11: ffffffff81b0c260 R12: 0000000000000000 R13: 1ffff92000000d99 R14: ffffc90000006cc8 R15: ffffc90000006db8 FS: 0000000000000000(0000) GS:ffff88812545c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f940b000218 CR3: 000000007df94000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x10f/0x150 arch/x86/kernel/stacktrace.c:27 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:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4873 skb_ext_maybe_cow net/core/skbuff.c:7092 [inline] skb_ext_add+0x1b6/0x8f0 net/core/skbuff.c:7167 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:169 [inline] br_nf_forward_ip+0xc3/0xa30 net/bridge/br_netfilter_hooks.c:681 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 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 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_handle_frame_finish+0x14c2/0x1bb0 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+0xa3a/0xd70 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:184 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/0x31a0 net/core/dev.c:6063 __netif_receive_skb_one_core net/core/dev.c:6174 [inline] __netif_receive_skb net/core/dev.c:6289 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6640 __napi_poll+0xae/0x340 net/core/dev.c:7704 napi_poll net/core/dev.c:7767 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7924 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 rds_tcp_conn_path_connect+0x6de/0x930 net/rds/tcp_connect.c:204 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 4798 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 veth0_to_bridge with own address as source address (addr:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, vlan:0) net_ratelimit: 6357 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 veth0_to_bridge with own address as source address (addr:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, 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:ae:c1:3a:03:93:e6, vlan:0)