xfrm: esp: avoid in-place decrypt on shared skb frags (CVE-2026-43284)

In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSGSPLICEPAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFLSHAREDFRAG after skbsplicefromiter, so later paths that may modify packet data ca...