bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:e3:bd:6e:4f:c9, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23817/1:b..l.. P23814/1:b..l.. rcu: (detected by 1, t=10510 jiffies, g=112777, q=1794 ncpus=2) task:syz.3.4466 state:R running task stack:26120 pid:23814 tgid:23814 ppid:18295 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5820 kernel/sched/core.c:7382 preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7561 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:201 [inline] _raw_spin_unlock+0x41/0x50 kernel/locking/spinlock.c:213 spin_unlock include/linux/spinlock.h:401 [inline] zap_pte_range mm/memory.c:2095 [inline] zap_pmd_range mm/memory.c:2151 [inline] zap_pud_range mm/memory.c:2179 [inline] zap_p4d_range mm/memory.c:2200 [inline] __zap_vma_range+0x40e1/0x4f70 mm/memory.c:2240 unmap_vmas+0x38b/0x550 mm/memory.c:2309 exit_mmap+0x293/0x9f0 mm/mmap.c:1315 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x18e/0x240 kernel/exit.c:586 do_exit+0x6a8/0x2360 kernel/exit.c:967 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 kernel/signal.c:3112 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+0x10e/0x770 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:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff757d9f2c2 RSP: 002b:00007ffcc74bd1f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: 0000001b32e64000 RBX: 0000001b32e64000 RCX: 00007ff757d9f2c2 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b32e64000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 0000000000000112 R13: 00000000000927c0 R14: 0000000000088e63 R15: 00007ffcc74bd4d0 task:syz-executor state:R running task stack:28168 pid:23817 tgid:23817 ppid:17369 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5820 kernel/sched/core.c:7382 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline] irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947 Code: ff ff ff e8 e0 ca 50 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 e2 d4 f7 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 7f d2 53 0a cc 48 8d 3d c7 d3 db RSP: 0018:ffffc900061b7640 EFLAGS: 00000292 RAX: 39b46a92d4f3c500 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000009a5da58a RSI: ffffffff8e70fdbc RDI: ffffffff8c6e1780 RBP: ffff88803e760000 R08: ffffffff8178699f R09: 0000000000000000 R10: ffffc900061b7778 R11: ffffffff81b301f0 R12: ffffffff8fd59ca0 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0xac/0x2550 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 save_stack+0x122/0x230 mm/page_owner.c:183 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962 __slab_free+0x274/0x2c0 mm/slub.c:5823 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:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_lru_noprof+0x29e/0x5f0 mm/slub.c:5029 __d_alloc+0x37/0x820 fs/dcache.c:1923 d_alloc+0x4b/0x190 fs/dcache.c:2009 lookup_one_qstr_excl+0xd8/0x360 fs/namei.c:1806 __start_dirop fs/namei.c:2920 [inline] start_dirop fs/namei.c:2942 [inline] filename_create+0x20e/0x370 fs/namei.c:5102 filename_symlinkat+0xf7/0x410 fs/namei.c:5823 __do_sys_symlinkat fs/namei.c:5849 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5844 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3f9eb9e617 RSP: 002b:00007ffe9d6d1c08 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3f9eb9e617 RDX: 00007f3f9ec37b03 RSI: 00000000ffffff9c RDI: 00007ffe9d6d1ca0 RBP: 00007ffe9d6d1c4c R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000138 R13: 00000000000927c0 R14: 0000000000088e81 R15: 00007ffe9d6d1ca0 rcu: rcu_preempt kthread starved for 274 jiffies! g112777 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5820 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330 kthread+0x38b/0x480 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: CPU: 1 UID: 0 PID: 7050 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Workqueue: krds_cp_wq#3/7 rds_connect_worker RIP: 0010:dev_get_by_index_rcu+0x9/0x110 net/core/dev.c:1043 Code: 5e 41 5f 5d c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 <41> 54 53 89 f3 49 89 fe 49 bc 00 00 00 00 00 fc ff df e8 f0 32 0b RSP: 0018:ffffc90000a07ec0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880aa9d6614 RCX: dffffc0000000000 RDX: 8000000000000100 RSI: 000000000000001d RDI: ffff888076ac27c0 RBP: ffffc90000a08010 R08: 0000000000000100 R09: 0000000000000000 R10: 0000000000000003 R11: ffffffff8acbaf50 R12: 1ffff92000140fe8 R13: dffffc0000000000 R14: 1ffff110155a4b06 R15: 1ffff110155a4b0d FS: 0000000000000000(0000) GS:ffff888123b6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555803da38 CR3: 0000000077784000 CR4: 00000000003526f0 Call Trace: nf_bridge_get_physindev include/linux/netfilter_bridge.h:63 [inline] br_nf_forward_finish+0x7f6/0xea0 net/bridge/br_netfilter_hooks.c:653 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:325 br_nf_forward_ip+0x7e7/0xa30 net/bridge/br_netfilter_hooks.c:722 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:633 nf_hook include/linux/netfilter.h:280 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323 __br_forward+0x41e/0x5d0 net/bridge/br_forward.c:130 deliver_clone net/bridge/br_forward.c:146 [inline] maybe_deliver+0x373/0x5b0 net/bridge/br_forward.c:212 br_flood+0x142/0x650 net/bridge/br_forward.c:345 br_handle_frame_finish+0x11fc/0x1ae0 net/bridge/br_input.c:231 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:325 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_bridge_pre net/bridge/br_input.c:293 [inline] br_handle_frame+0x1329/0x1600 net/bridge/br_input.c:453 __netif_receive_skb_core+0x989/0x30c0 net/core/dev.c:6292 __netif_receive_skb_one_core net/core/dev.c:6403 [inline] __netif_receive_skb net/core/dev.c:6518 [inline] process_backlog+0x727/0x18b0 net/core/dev.c:6869 __napi_poll+0xaa/0x330 net/core/dev.c:7938 napi_poll net/core/dev.c:8001 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8158 handle_softirqs+0x265/0x8d0 kernel/softirq.c:669 do_softirq+0x77/0xd0 kernel/softirq.c:569 __local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473 lock_sock include/net/sock.h:1717 [inline] __inet6_bind+0x301/0xf30 net/ipv6/af_inet6.c:292 kernel_bind+0x13e/0x1c0 net/socket.c:3677 rds_tcp_conn_path_connect+0x53b/0x920 net/rds/tcp_connect.c:175 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 kthread+0x38b/0x480 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