GHSA-5MFQ-X364-3H2R
Vulnerability from github – Published: 2026-10-06 09:31 – Updated: 2026-10-07 09:32In 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().
{
"affected": [],
"aliases": [
"CVE-2026-98241"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-10-06T09:18:12Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: xfrm: use full sockets in local error paths\n\nxfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb-\u003esk as if it\nalways pointed at a full IPv6 socket.\n\nThat is not guaranteed. TCP SYN-ACK skbs can be owned by a\nTCP_NEW_SYN_RECV request_sock while the output path itself is driven by the\nfull listener. If rerouting selects an IPv6 XFRM tunnel route with a lower\nMTU, the local PMTU/error handling path can reach these callbacks with that\nmini-socket still attached to the skb.\n\nThe callbacks then miscast the request socket as a full inet/IPv6 socket and\ncan read beyond the request_sock allocation when they access inet_sock or\nipv6_pinfo state.\n\nResolve the owner with skb_to_full_sk() in both callbacks and bail out when\nno full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error\nlogic, which already reasons about full sockets with skb_to_full_sk().",
"id": "GHSA-5mfq-x364-3h2r",
"modified": "2026-10-07T09:32:14Z",
"published": "2026-10-06T09:31:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98241"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4c030a0400ebfd2318361c923a88103b2c67c49f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/60459c670329d586a58db5d8f811fa5accfe4862"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/675919e08ce266b8cac11fd9af29170e762a480f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6973a21ee73c5567f883813c8ef414774b45892f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/904a0e827d0d7189271a3a2eb648293809f25efc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b1a88633c36d2cbc3831382f3846754d344276fd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c21f3f7fbfeda7c5794f606cb0ffcc2d9001eef8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ca3d68c3213475b53db6647e159dc73bd1af5ab1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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