CVE-2026-52986 netfilter: nf_conntrack_sip: don't use simple_strtoul

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfconntracksip: don't use simplestrtoul Replace unsafe port parsing in epaddrlen, ctsipparseheaderuri, and ctsipparserequest with a new sipparseport helper that validates each digit against the buffer limit, eliminatin...