CVE-2026-72137
In the Linux kernel, the following vulnerability has been resolved: xfrm: nat_keepalive: avoid double free on send error nat_keepalive_send() frees the keepalive skb whenever the IPv4 or IPv6 send helper reports an error. That cleanup is only correct before the skb is handed to the output path. Once ip_build_and_send_pkt() or ip6_xmit() takes ownership, the networking stack may already have consumed the skb before returning an error, so freeing it again is unsafe. Handle the pre-handoff failure cases inside nat_keepalive_send_ipv4() and nat_keepalive_send_ipv6(), where the caller still owns the skb, and keep nat_keepalive_send() responsible only for family dispatch and the unsupported-family cleanup path.
- Score
- CVSS 3.1 9.8 Critical
- Status
- Received - 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- Published
- 2026-08-15
- Last modified
- 2026-08-17
Affected products
References
- https://git.kernel.org/stable/c/226f4a490d1a938fc838d8f8c46a4eca864c0d78
- https://git.kernel.org/stable/c/5b0c4c916f202b8fd13d12afb6af62b385622f81
- https://git.kernel.org/stable/c/a8a7e6a9ff8a4c1f067694ddbd44be67fdf36693
- https://git.kernel.org/stable/c/d0a4dc7efa825bce60a8da8f7d43c864a159abde
