Use-after-free in Linux kernel's netfilter: nf_tables component

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation.

The nft_verdict_init() function allows positive values as drop error within the hook verdict, and hence the nf_hook_slow() function can cause a double free vulnerability when NF_DROP is issued with a drop error which resembles NF_ACCEPT.

We recommend upgrading past commit f342de4e2f33e0e39165d8639387aa6c19dff660.