CVE-2026-98241

ipv6: xfrm: use full sockets in local error paths

State: Published
Severity: 7.8 High
Published: Oct 6, 2026
Updated: Oct 19, 2026
Reserved: Sep 25, 2026

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().

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	dd767856a36e00b631d65ebc4bb81b19915532d6 to before b1a88633c36d2cbc3831382f3846754d344276fdAffected dd767856a36e00b631d65ebc4bb81b19915532d6 to before 904a0e827d0d7189271a3a2eb648293809f25efcAffected dd767856a36e00b631d65ebc4bb81b19915532d6 to before 675919e08ce266b8cac11fd9af29170e762a480fAffected dd767856a36e00b631d65ebc4bb81b19915532d6 to before 60459c670329d586a58db5d8f811fa5accfe4862Affected dd767856a36e00b631d65ebc4bb81b19915532d6 to before ca3d68c3213475b53db6647e159dc73bd1af5ab1Affected dd767856a36e00b631d65ebc4bb81b19915532d6 to before 4c030a0400ebfd2318361c923a88103b2c67c49fAffected dd767856a36e00b631d65ebc4bb81b19915532d6 to before c21f3f7fbfeda7c5794f606cb0ffcc2d9001eef8Affected dd767856a36e00b631d65ebc4bb81b19915532d6 to before 6973a21ee73c5567f883813c8ef414774b45892fAffected
LinuxLinux	3.2Affected before 3.2Not affected 5.10.271 through 5.10.Not affected 5.15.222 through 5.15.Not affected 6.1.189 through 6.1.Not affected 6.6.158 through 6.6.Not affected 6.12.112 through 6.12.Not affected 6.18.54 through 6.18.Not affected 7.2.8 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

dd767856a36e00b631d65ebc4bb81b19915532d6 to before b1a88633c36d2cbc3831382f3846754d344276fdAffected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before 904a0e827d0d7189271a3a2eb648293809f25efcAffected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before 675919e08ce266b8cac11fd9af29170e762a480fAffected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before 60459c670329d586a58db5d8f811fa5accfe4862Affected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before ca3d68c3213475b53db6647e159dc73bd1af5ab1Affected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before 4c030a0400ebfd2318361c923a88103b2c67c49fAffected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before c21f3f7fbfeda7c5794f606cb0ffcc2d9001eef8Affected
dd767856a36e00b631d65ebc4bb81b19915532d6 to before 6973a21ee73c5567f883813c8ef414774b45892fAffected

LinuxLinux

3.2Affected
before 3.2Not affected
5.10.271 through 5.10.*Not affected
5.15.222 through 5.15.*Not affected
6.1.189 through 6.1.*Not affected
6.6.158 through 6.6.*Not affected
6.12.112 through 6.12.*Not affected
6.18.54 through 6.18.*Not affected
7.2.8 through 7.2.*Not affected
7.3 and laterNot affected

References

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