CVE-2026-98241

/// Technical description

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

ipv6: xfrm: use full sockets in local error paths

xfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it

always pointed at a full IPv6 socket.

That is not guaranteed. TCP SYN-ACK skbs can be owned by a

TCP_NEW_SYN_RECV request_sock while the output path itself is driven by the

full listener. If rerouting selects an IPv6 XFRM tunnel route with a lower

MTU, the local PMTU/error handling path can reach these callbacks with that

mini-socket still attached to the skb.

The callbacks then miscast the request socket as a full inet/IPv6 socket and

can read beyond the request_sock allocation when they access inet_sock or

ipv6_pinfo state.

Resolve the owner with skb_to_full_sk() in both callbacks and bail out when

no full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error

logic, which already reasons about full sockets with skb_to_full_sk().

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References