CVE-2026-98802 seg6: ensure packet data is writable before modifying SRH and IPv6 DA

In the Linux kernel, the following vulnerability has been resolved: seg6: ensure packet data is writable before modifying SRH and IPv6 DA advancenextseg modifies the SRH Segments Left field and the IPv6 destination address without ensuring the packet data is writable. seg6nextcsidadvancearg has t...