rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=22fc/1/0x4000000000000000 softirq=20556/20557 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=28993, q=1138 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc1-syzkaller-00377-ga5ea26536e89 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:advance_sched+0x378/0xc60 net/sched/sch_taprio.c:975 Code: 44 8b 74 24 28 4c 89 6c 24 60 4c 89 7c 24 08 48 89 54 24 70 eb 71 e8 e7 5d 22 f9 48 8b 04 24 49 83 fd 0f 48 8b 80 50 01 00 00 <0f> 87 6b 07 00 00 48 01 c3 49 83 fd 0f 0f 87 7c 07 00 00 e8 c0 5d RSP: 0018:ffffc90000007d90 EFLAGS: 00000093 RAX: 1786133b10a2b539 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888016a75940 RSI: ffffffff88657a69 RDI: 0000000000000006 RBP: ffff888021a43c00 R08: 0000000000000006 R09: 0000000000000000 R10: 00000000000007ff R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: 00000000000007ff FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6103977978 CR3: 000000001d046000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x203/0xc10 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1063 [inline] __sysvec_apic_timer_interrupt+0x105/0x3f0 arch/x86/kernel/apic/apic.c:1080 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x20 kernel/kcov.c:310 Code: 00 00 f3 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 9a fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 8b 0c 24 <48> 89 f2 48 89 fe bf 07 00 00 00 e9 78 fe ff ff 0f 1f 84 00 00 00 RSP: 0018:ffffc900000d7610 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc900000d7698 RCX: ffffffff813a4925 RDX: ffff888016a75940 RSI: ffffffff882acc75 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8880b9829418 R12: ffffffff882acc75 R13: 0000000000000000 R14: ffffc900000d7758 R15: ffffc900000d76cd orc_find arch/x86/kernel/unwind_orc.c:202 [inline] unwind_next_frame+0x1b5/0x2390 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x185/0x3f0 mm/slub.c:3523 kmalloc_reserve+0x166/0x260 net/core/skbuff.c:559 __alloc_skb+0x12b/0x330 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] nlmsg_new include/net/netlink.h:999 [inline] __neigh_notify+0x83/0x160 net/core/neighbour.c:3502 neigh_cleanup_and_release+0x8f/0x280 net/core/neighbour.c:101 neigh_periodic_work+0x672/0xb60 net/core/neighbour.c:994 process_one_work+0x887/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8bb/0x1290 kernel/workqueue.c:2784 kthread+0x33a/0x430 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:304 rcu: rcu_preempt kthread starved for 10487 jiffies! g28993 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:29056 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1613 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1812 kthread+0x33a/0x430 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:304 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 2836 Comm: kworker/u4:9 Not tainted 6.6.0-rc1-syzkaller-00377-ga5ea26536e89 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:queued_write_lock_slowpath+0x176/0x330 kernel/locking/qrwlock.c:85 Code: 00 00 8b 03 3d 00 01 00 00 74 37 48 b8 00 00 00 00 00 fc ff df 48 89 d9 48 89 da 48 c1 e9 03 83 e2 07 48 01 c1 83 c2 03 f3 90 <0f> b6 01 38 c2 7c 08 84 c0 0f 85 59 01 00 00 8b 03 3d 00 01 00 00 RSP: 0018:ffffc900001f0460 EFLAGS: 00000206 RAX: 00000000000001ff RBX: ffffffff8e7d9a80 RCX: fffffbfff1cfb350 RDX: 0000000000000003 RSI: 0000000000000004 RDI: ffffffff8e7d9a80 RBP: 1ffff9200003e08e R08: 0000000000000001 R09: fffffbfff1cfb350 R10: ffffffff8e7d9a83 R11: 0200000000000000 R12: ffffffff8e7d9a84 R13: 0000000000000003 R14: fffffbfff1cfb350 R15: ffffc900001f04a0 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd7907c5d58 CR3: 000000000c976000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: queued_write_lock include/asm-generic/qrwlock.h:101 [inline] do_raw_write_lock+0x1d2/0x3b0 kernel/locking/spinlock_debug.c:210 ___neigh_create+0x9c2/0x2a50 net/core/neighbour.c:674 ip6_finish_output2+0x10a5/0x1b20 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:196 [inline] ip6_finish_output+0x485/0x1250 net/ipv6/ip6_output.c:207 NF_HOOK_COND include/linux/netfilter.h:293 [inline] ip6_output+0x23a/0x880 net/ipv6/ip6_output.c:228 dst_output include/net/dst.h:458 [inline] NF_HOOK.constprop.0+0xfd/0x540 include/linux/netfilter.h:304 ndisc_send_skb+0x9f6/0x1440 net/ipv6/ndisc.c:509 ndisc_send_rs+0x133/0x690 net/ipv6/ndisc.c:719 addrconf_rs_timer+0x412/0x840 net/ipv6/addrconf.c:3973 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x764/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:csd_lock_wait kernel/smp.c:300 [inline] RIP: 0010:smp_call_function_many_cond+0x4d6/0x1570 kernel/smp.c:844 Code: 0b 00 85 ed 74 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 dc 8c 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 RSP: 0018:ffffc9000a7b7928 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9844180 RCX: 0000000000000000 RDX: ffff8880275bbb80 RSI: ffffffff817c4b74 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1017308831 R13: 0000000000000001 R14: ffff8880b993d8c0 R15: ffff8880b9844188 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1012 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1998 [inline] text_poke_bp_batch+0x83a/0x960 arch/x86/kernel/alternative.c:2208 text_poke_flush arch/x86/kernel/alternative.c:2399 [inline] text_poke_flush arch/x86/kernel/alternative.c:2396 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2406 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+0x887/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8bb/0x1290 kernel/workqueue.c:2784 kthread+0x33a/0x430 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:304