ipv6: fix use-after-free in ip6_finish_output2() (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.19 % · percentile 9 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Received
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix use-after-free in ip6_finish_output2() ip6_finish_output2() caches a pointer to the IPv6 destination address (daddr) before invoking lwtunnel_xmit(). The LWT-BPF transmit path or other encapsulation operations within lwtunnel_xmit() can reallocate the skb head, freeing the memory that daddr points to. When lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, the function continues to use the stale daddr pointer to compute the nexthop and to look up or create the neighbour entry. This results in a use-after-free read, which can leak sensitive kernel data, pollute the neighbour table with arbitrary values, misdirect traffic, or crash the system. Fix this by re-fetching the IPv6 header and the destination address pointer after lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop computation and neighbour lookup operate on valid memory.
References
- https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a
- https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed
- https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f
- https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a
- https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862
- https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43
- https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515
- https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3
- https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e
European references
- ENISA EUVD · EUVD-2026-71435
- GCVE · GCVE-0-2026-80792
CERT-FR advisories
- CERTFR-2026-AVI-1431 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1373 — Multiples vulnérabilités dans les produits Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1287 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1232 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1163 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 4132c4ad00ddbf3a175ea0d2c775b662a32f4c85 < 75e0a544ebe9af663ef53ca21e9e9185c51fb54a ; affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 < c95f01b78266828a57060d754fcbfc92123a98ed ; affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 < d960881b9312e781a3429aabceb223ce6b7c882f ; affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 < 087ee0d914aaae929f1660c9ca878e367655ba1a ; affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 < 3c770ac4e6f07af7c7b40c474a3efc61ffed7862 ; affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 < 3dc98e5fe82d069dd29b124ffbdb679331dfea43 |
| Linux · Linux | affected 5.15 ; unaffected 0 < 5.15 ; unaffected 5.10.267 ≤ 5.10.* ; unaffected 5.15.218 ≤ 5.15.* ; unaffected 6.1.185 ≤ 6.1.* ; unaffected 6.6.154 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |