CVE-2026-68426 xfrm: fix stale skb->prev after async crypto steals a GSO segment

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix stale skb-prev after async crypto steals a GSO segment skbgsosegment leaves the segment list head with -prev pointing at the last segment, an invariant validatexmitskblist relies on when it sets its tail pointer tail =...