rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18160/1:b..l rcu: (detected by 1, t=10503 jiffies, g=78573, q=615 ncpus=2) task:syz.6.1365 state:R running task stack:25336 pid:18160 tgid:18160 ppid:9937 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5290 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6902 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7086 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457 nl80211_netlink_notify+0x46b/0x840 net/wireless/nl80211.c:21517 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x1214/0x1aa0 net/netlink/af_netlink.c:761 __sock_release+0xb9/0x250 net/socket.c:666 sock_close+0x1c/0x30 net/socket.c:1470 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb4d8b8f749 RSP: 002b:00007ffda1170a98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fb4d8de7da0 RCX: 00007fb4d8b8f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fb4d8de7da0 R08: 0000000000000000 R09: 00000008a1170d8f R10: 00007fb4d8de7cb0 R11: 0000000000000246 R12: 000000000007edad R13: 00007fb4d8de6090 R14: ffffffffffffffff R15: 00007ffda1170bb0 rcu: rcu_preempt kthread starved for 2570 jiffies! g78573 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:27680 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5290 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6902 __schedule_loop kernel/sched/core.c:6984 [inline] schedule+0x165/0x360 kernel/sched/core.c:6999 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 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: 9 Comm: kworker/0:0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_long defense_work_handler RIP: 0010:mark_lock+0x9a/0x190 kernel/locking/lockdep.c:4774 Code: 0e 00 75 13 48 8d 3d c5 c7 28 0e 48 c7 c6 e6 b5 b9 8d 67 48 0f b9 3a 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 85 69 60 74 10 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 87 30 cc 09 cc 49 89 fe 49 89 f7 RSP: 0018:ffffc900000069c0 EFLAGS: 00000006 RAX: 0000000000000001 RBX: 0000000000000009 RCX: ffffffff936ff928 RDX: 0000000000000008 RSI: ffff88801d6c8b80 RDI: ffff88801d6c8000 RBP: 0000000000000200 R08: ffffffff81f1723a R09: ffffffff8e344ce0 R10: dffffc0000000000 R11: ffffed10170c757a R12: 0000000000000002 R13: ffff88801d6c8b80 R14: ffff88801d6c8000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881259ad000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe3ede4b2c CR3: 000000007ed90000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4674 [inline] __lock_acquire+0x6b6/0x2cf0 kernel/locking/lockdep.c:5191 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] perf_event_task_tick+0x146/0x390 kernel/events/core.c:4659 sched_tick+0x4c3/0x840 kernel/sched/core.c:5577 update_process_times+0x270/0x2f0 kernel/time/timer.c:2479 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x3e9/0x710 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x453/0x550 kernel/printk/printk.c:2427 Code: 0f 84 44 ff ff ff e8 3c e9 1f 00 fb eb 44 e8 34 e9 1f 00 e8 7f d1 c6 09 4d 85 f6 74 94 e8 25 e9 1f 00 fb 48 c7 c7 e0 8b 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 65 2d RSP: 0018:ffffc90000007100 EFLAGS: 00000246 RAX: ffffffff81a1807b RBX: ffffffff81a17ef5 RCX: ffff88801d6c8000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8e338be0 RBP: ffffc900000071b0 R08: ffffffff8fc479f7 R09: 1ffffffff1f88f3e R10: dffffc0000000000 R11: fffffbfff1f88f3f R12: 000000000000006e R13: 0000000000000000 R14: 0000000000000200 R15: 0000000000000000 _printk+0xcf/0x120 kernel/printk/printk.c:2453 br_fdb_update+0x62d/0x690 net/bridge/br_fdb.c:1003 br_handle_frame_finish+0x587/0x1c90 net/bridge/br_input.c:144 br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 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+0x96e/0x14f0 net/bridge/br_input.c:442 __netif_receive_skb_core+0x95f/0x2f90 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6265 process_backlog+0x54f/0x1340 net/core/dev.c:6617 __napi_poll+0xae/0x320 net/core/dev.c:7681 napi_poll net/core/dev.c:7744 [inline] net_rx_action+0x64a/0xe00 net/core/dev.c:7896 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:626 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] update_defense_level+0x8d2/0xd80 net/netfilter/ipvs/ip_vs_ctl.c:209 defense_work_handler+0x2d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:234 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 9396 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:7b:07:09:46:b3, 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:fe:7b:07:09:46:b3, 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:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:7b:07:09:46:b3, 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:fe:7b:07:09:46:b3, 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:aa:aa:aa:aa:aa:0c, vlan:0)