rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=ca5/1/0x4000000000000000 softirq=7272/7273 fqs=0 
	(t=10502 jiffies g=8253 q=95)
rcu: rcu_preempt kthread starved for 10503 jiffies! g8253 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:26712 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: netns cleanup_net
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x1b4/0x200 arch/x86/kernel/kvm.c:918
Code: e0 48 c1 e8 03 42 0f b6 04 28 84 c0 75 42 45 0f b6 34 24 e8 7e d7 4e 00 44 3a 74 24 1c 75 10 66 90 0f 00 2d ce 7c 50 09 fb f4 <e9> c8 fe ff ff fb e9 c2 fe ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 54
RSP: 0000:ffffc90000ce7840 EFLAGS: 00000246
RAX: 4c5912f17a3a8500 RBX: 1ffff9200019cf0c RCX: ffffffff81631ae8
RDX: dffffc0000000000 RSI: ffffffff8a8b2b00 RDI: ffffffff8ad904c0
RBP: ffffc90000ce7910 R08: dffffc0000000000 R09: fffffbfff20e241a
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8ca4f840
R13: dffffc0000000000 R14: 0000000000000003 R15: ffffc90000ce7880
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555c55c3bb40 CR3: 0000000063021000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x6bc/0xc40 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x269/0x370 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:363 [inline]
 unregister_sysctl_table+0x80/0x130 fs/proc/proc_sysctl.c:1715
 unix_sysctl_unregister+0x58/0x70 net/unix/sysctl_net_unix.c:55
 unix_net_exit+0x11/0x50 net/unix/af_unix.c:3372
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x6ce/0xb60 net/core/net_namespace.c:599
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 4171 Comm: syz-executor.2 Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67
Code: c1 0f 8c dc fc ff ff 48 89 df e8 a8 74 91 00 48 ba 00 00 00 00 00 fc ff df e9 c5 fc ff ff 66 0f 1f 84 00 00 00 00 00 48 8b 07 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 31 c0 81 ff 03 00 00 40 0f
RSP: 0000:ffffc900000074e0 EFLAGS: 00000283
RAX: ffffffff81557d45 RBX: ffffc90003057a50 RCX: ffffffff8df87994
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc90003057a50
RBP: ffffc90003058000 R08: 0000000000000001 R09: ffffc90000007690
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1cc2a8a
R13: 1ffffffff1cc2a8a R14: ffffc90003050000 R15: ffffc900000075a0
 deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline]
 unwind_next_frame+0xb35/0x1fa0 arch/x86/kernel/unwind_orc.c:539
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc_node_track_caller+0x195/0x390 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x12c/0x590 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1167 [inline]
 ndisc_alloc_skb+0xee/0x2c0 net/ipv6/ndisc.c:423
 ndisc_send_rs+0x269/0x6a0 net/ipv6/ndisc.c:689
 addrconf_rs_timer+0x357/0x610 net/ipv6/addrconf.c:3959
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 f2 3e 8c f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 87 87 19 f7 65 8b 05 08 8a c4 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0000:ffffc90003057240 EFLAGS: 00000206
RAX: fe5a22c4615ab600 RBX: 1ffff9200060ae4c RCX: ffffffff81631ae8
RDX: dffffc0000000000 RSI: ffffffff8a8b2b00 RDI: 0000000000000001
RBP: ffffc900030572d0 R08: dffffc0000000000 R09: fffffbfff20e241a
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff9200060ae48 R14: ffffc90003057260 R15: 0000000000000246
 debug_object_activate+0x2f4/0x4e0 lib/debugobjects.c:711
 debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline]
 kvfree_call_rcu+0xb6/0x8a0 kernel/rcu/tree.c:3587
 drop_sysctl_table+0x317/0x460 fs/proc/proc_sysctl.c:1678
 drop_sysctl_table+0x329/0x460 fs/proc/proc_sysctl.c:1681
 drop_sysctl_table+0x329/0x460 fs/proc/proc_sysctl.c:1681
 unregister_sysctl_table+0x88/0x130 fs/proc/proc_sysctl.c:1716
 lowpan_frags_ns_sysctl_unregister net/ieee802154/6lowpan/reassembly.c:402 [inline]
 lowpan_frags_exit_net+0x5c/0xb0 net/ieee802154/6lowpan/reassembly.c:475
 ops_exit_list net/core/net_namespace.c:172 [inline]
 setup_net+0x78f/0x9e0 net/core/net_namespace.c:355
 copy_net_ns+0x392/0x5d0 net/core/net_namespace.c:476
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 copy_namespaces+0x365/0x3b0 kernel/nsproxy.c:178
 copy_process+0x1841/0x3ef0 kernel/fork.c:2209
 kernel_clone+0x210/0x960 kernel/fork.c:2604
 __do_sys_clone kernel/fork.c:2721 [inline]
 __se_sys_clone kernel/fork.c:2705 [inline]
 __x64_sys_clone+0x23f/0x290 kernel/fork.c:2705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f34beb87da9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34bdec6078 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f34becb6120 RCX: 00007f34beb87da9
RDX: 0000000000000000 RSI: 0100000000000000 RDI: 0030626f7c2a0000
RBP: 00007f34bebd447a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 000000000000006e R14: 00007f34becb6120 R15: 00007ffea99722e8
 </TASK>