100% CPU utilization when running iptables (nft interface) as non-root user

[Amish <anon.amish@xxxxxxxxx>]

Hello,

I am using pure nftables. (via nft tool)

But my system also has iptables binaries installed (nft interface)

If I run iptables -nvL as root, it works fine. i.e. it shows empty tables

# iptables -nvL
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out source               
destination

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out source               
destination

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out source               destination


But if I run it as any non-root user. It outputs nothing but uses 100% 
CPU till I kill it with Ctrl-C

$ iptables -nvL
^C
iptables -nvL  51.74s user 81.30s system 99% cpu 2:13.92 total

$ iptables -A INPUT -j ACCEPT
^C
iptables -A INPUT -j ACCEPT  8.19s user 12.65s system 99% cpu 20.897 total


iptables without arguments does not hang. It hangs only when a command 
is specified.

How to find the root cause? Is it iptables bug or kernel bug?

# iptables --version
iptables v1.8.3 (nf_tables)

# nft --version
nftables v0.9.1 (Headless Horseman)

# uname -r
5.2.0-arch2-1-ARCH

Thanks and regards,

Amish