rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P31955/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=177393, q=1229 ncpus=1)
task:syz.2.12569     state:R  running task     stack:27304 pid:31955 tgid:31954 ppid:6205   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6908
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235
 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xf4/0x1ea0 arch/x86/kernel/unwind_orc.c:498
Code: 7e 8e e8 0f ac 2c 00 e8 7a 34 d5 09 5a 85 c0 0f 85 16 06 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8d 65 50 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 08 17 00 00 4d 8b 75 50 4d 85 f6 74 36 49 8d be
RSP: 0018:ffffc900063571f0 EFLAGS: 00000a06
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 1ffff92000c6ae56 RSI: ffffffff8c1af720 RDI: ffffffff8e12b8e0
RBP: ffffc900063572a8 R08: 00000000f8eba1fd R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: ffffc900063572b0
R13: ffffc90006357260 R14: 0000000000000000 R15: ffff888068f41e80
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5263 [inline]
 __kmalloc_noprof+0x301/0x850 mm/slub.c:5275
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 new_dir fs/proc/proc_sysctl.c:966 [inline]
 get_subdir fs/proc/proc_sysctl.c:1010 [inline]
 sysctl_mkdir_p fs/proc/proc_sysctl.c:1320 [inline]
 __register_sysctl_table+0xbe4/0x1650 fs/proc/proc_sysctl.c:1395
 neigh_sysctl_register+0x326/0x660 net/core/neighbour.c:3922
 devinet_sysctl_register+0xb6/0x210 net/ipv4/devinet.c:2714
 inetdev_init+0x2b8/0x570 net/ipv4/devinet.c:291
 inetdev_event+0x7fa/0x17f0 net/ipv4/devinet.c:1590
 notifier_call_chain+0x99/0x420 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x16e6/0x2210 net/core/dev.c:11462
 __ip_tunnel_create+0x52b/0x670 net/ipv4/ip_tunnel.c:268
 ip_tunnel_init_net+0x230/0x780 net/ipv4/ip_tunnel.c:1147
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3174
 __do_sys_unshare kernel/fork.c:3245 [inline]
 __se_sys_unshare kernel/fork.c:3243 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3243
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc1219c799
RSP: 002b:00007fbc130b1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fbc12415fa0 RCX: 00007fbc1219c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080
RBP: 00007fbc12232bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc12416038 R14: 00007fbc12415fa0 R15: 00007fffc94b9568
 </TASK>