Linux kernel versions 6.19.5 and 6.18.15 have introduced a performance improvement for users utilizing iptables-compatible firewalls through the new .abort_skip_removal flag, which enhances rule deletion speed. This tweak allows the pipapo set backend to ignore unnecessary element removal during an abort sequence, leading to faster deletions. Users can check if they are running the updated kernel by using the "uname -r" command in the terminal or checking for the flag in the system files. While the optimization benefits those with dynamic nftables configurations, users with static rule sets may not need to rush into updating and should wait for downstream distribution validation if their systems rely on deterministic firewall behavior

Linux Kernel 6.19.5 and 6.18.15: What You Need to Know About Netfilter Tweaks

Linux kernel versions 6.19.5 and 6.18.15 have been released, bringing a tweak to the nf_tables subsystem that improves performance for users who rely on iptables-compatible firewalls. The new .abort_skip_removal flag allows the pipapo set backend to ignore element removal during an abort sequence, resulting in faster rule deletions by up to a few milliseconds. To verify if you're running a patched kernel, type "uname -r" in a terminal and check for specific strings indicating the updated version, or use "grep abort_skip_removal /proc/kallsyms." Users who don't rely on pipapo's performance optimization can consider holding back from updating to these kernel versions until downstream distributions have vetted the change.

Linux Kernel 6.19.5 and 6.18.15: What You Need to Know About Netfilter Tweaks @ Linux Compatible