CVE-2026-46244

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nftinner: Fix IPv6 innerthoff desync

In nftinnerparsel2l3(), when processing inner IPv6 packets, ipv6findhdr() correctly computes the transport header offset traversing all extension headers, but the result is immediately overwritten with nhoff + sizeof(ip6h) (40 bytes), which only accounts for the IPv6 base header. This creates a desync between innerthoff (wrong — points to extension header start) and l4proto (correct — e.g., IPPROTOTCP), enabling transport header forgery and potential firewall bypass. This issue affects stable versions from Linux 6.2.

For comparison, the normal (non-inner) IPv6 path correctly preserves ipv6findhdr()'s result. Removing the incorrect overwrite ensures that ipv6findhdr()'s calculated transport header offset is preserved, thereby fixing the desynchronization.