rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=b8cc/1/0x4000000000000000 softirq=6796/6796 fqs=7 rcu: (detected by 1, t=10503 jiffies, g=8141, q=266 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 782 Comm: kworker/0:2 Not tainted 6.6.0-syzkaller-15494-g6bc986ab839c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:lookup_object_or_alloc lib/debugobjects.c:564 [inline] RIP: 0010:debug_object_activate+0x1aa/0x490 lib/debugobjects.c:719 Code: 95 92 49 8d 84 24 20 45 95 92 48 89 cf 48 89 8d 20 ff ff ff 48 89 85 28 ff ff ff e8 d0 f9 1c 06 49 89 c1 48 8b 85 28 ff ff ff <48> c1 e8 03 80 3c 18 00 0f 85 84 02 00 00 49 8b 9c 24 20 45 95 92 RSP: 0018:ffffc90000006cd0 EFLAGS: 00000092 RAX: ffffffff92990e50 RBX: dffffc0000000000 RCX: ffffffff8169774e RDX: 1ffffffff25321cd RSI: 0000000000000004 RDI: ffffc90000006c40 RBP: ffffc90000006dc0 R08: 0000000000000001 R09: 0000000000000006 R10: 0000000000000003 R11: 000000000000020c R12: 000000000003c930 R13: ffff888050df8340 R14: ffffffff8acf3a20 R15: 1ffff92000000d9e FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3795a756c0 CR3: 000000002956f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_hrtimer_activate kernel/time/hrtimer.c:422 [inline] debug_activate kernel/time/hrtimer.c:477 [inline] enqueue_hrtimer+0x23/0x310 kernel/time/hrtimer.c:1087 __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0xa0a/0xc10 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x3f0 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x42/0xc0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5721 Code: c1 05 dd 7d 99 7e 83 f8 01 0f 85 b0 02 00 00 9c 58 f6 c4 02 0f 85 9b 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90000007088 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000000e13 RCX: 0000000000000001 RDX: 1ffff110038ed8c7 RSI: ffffffff8accbc20 RDI: ffffffff8b2eee80 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff23e41d0 R10: ffffffff91f20e87 R11: 0200000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8cfacfe0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] ip6_rcv_core+0x90/0x1da0 net/ipv6/ip6_input.c:163 ipv6_rcv+0xd5/0x720 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5527 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5641 netif_receive_skb_internal net/core/dev.c:5727 [inline] netif_receive_skb+0x133/0x700 net/core/dev.c:5786 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] br_pass_frame_up+0x310/0x7a0 net/bridge/br_input.c:68 br_handle_frame_finish+0xcab/0x1d80 net/bridge/br_input.c:216 br_nf_hook_thresh+0x2ff/0x410 net/bridge/br_netfilter_hooks.c:1044 br_nf_pre_routing_finish_ipv6+0x683/0xf20 net/bridge/br_netfilter_ipv6.c:148 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x3ce/0x8c0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x85e/0x15a0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x9df/0x1710 net/bridge/br_input.c:417 __netif_receive_skb_core.constprop.0+0x9f7/0x3f40 net/core/dev.c:5421 __netif_receive_skb_one_core+0xaf/0x180 net/core/dev.c:5525 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5641 process_backlog+0x101/0x6b0 net/core/dev.c:5969 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6531 napi_poll net/core/dev.c:6600 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6733 __do_softirq+0x21a/0x968 kernel/softirq.c:553 do_softirq kernel/softirq.c:454 [inline] do_softirq+0xaa/0xe0 kernel/softirq.c:441 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:381 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:817 [inline] __dev_queue_xmit+0xa6f/0x3d10 net/core/dev.c:4371 dev_queue_xmit include/linux/netdevice.h:3112 [inline] neigh_resolve_output net/core/neighbour.c:1556 [inline] neigh_resolve_output+0x58c/0x900 net/core/neighbour.c:1536 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x679/0x1830 net/ipv6/ip6_output.c:137 __ip6_finish_output net/ipv6/ip6_output.c:211 [inline] ip6_finish_output+0x3c7/0xf70 net/ipv6/ip6_output.c:222 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x1e2/0x530 net/ipv6/ip6_output.c:243 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ndisc_send_skb+0xa0c/0x18e0 net/ipv6/ndisc.c:509 ndisc_send_rs+0x133/0x6a0 net/ipv6/ndisc.c:719 addrconf_dad_completed+0x486/0x1030 net/ipv6/addrconf.c:4303 addrconf_dad_work+0x7f6/0x14b0 net/ipv6/addrconf.c:4211 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 7320 jiffies! g8141 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:28672 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xee2/0x59a0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe7/0x270 kernel/sched/core.c:6778 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1830 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.6.0-syzkaller-15494-g6bc986ab839c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x4db/0x1570 kernel/smp.c:855 Code: 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 0c c5 0b 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 3c 0e 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc90000107920 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b98441a0 RCX: ffffffff817cdbaa RDX: ffff888017e43b80 RSI: ffffffff817cdb84 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1017308835 R13: 0000000000000001 R14: ffff8880b993d8c0 R15: ffff8880b98441a8 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000502d50 CR3: 000000000cd77000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2006 [inline] text_poke_bp_batch+0x83a/0x960 arch/x86/kernel/alternative.c:2216 text_poke_flush arch/x86/kernel/alternative.c:2407 [inline] text_poke_flush arch/x86/kernel/alternative.c:2404 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2414 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32e/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:830 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242