ipv6: fix use-after-free in ip6_finish_output2()
Summary
| CVE | CVE-2026-80792 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-04 16:18:05 UTC |
| Updated | 2026-09-04 16:18:05 UTC |
| 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. |
Risk And Classification
EPSS: 0.001950000 probability, percentile 0.092810000 (date 2026-09-07)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 4132c4ad00ddbf3a175ea0d2c775b662a32f4c85 75e0a544ebe9af663ef53ca21e9e9185c51fb54a git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 c95f01b78266828a57060d754fcbfc92123a98ed git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 d960881b9312e781a3429aabceb223ce6b7c882f git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 087ee0d914aaae929f1660c9ca878e367655ba1a git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 3c770ac4e6f07af7c7b40c474a3efc61ffed7862 git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 3dc98e5fe82d069dd29b124ffbdb679331dfea43 git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 99219c82804f266189388e8bf1cf5135d10d5515 git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 73a187384a8c8b983c7fea046d716b6752a1e7a3 git | Not specified |
| CNA | Linux | Linux | affected e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 d0d48d999b0eee6bb176ef4e39d9be868fa80f7e git | Not specified |
| CNA | Linux | Linux | affected 1598154fd28ffa4a55beae1970475fd6776554b6 git | Not specified |
| CNA | Linux | Linux | affected 5.10.233 5.10.267 semver | Not specified |
| CNA | Linux | Linux | affected 5.4.289 5.5 semver | Not specified |
| CNA | Linux | Linux | affected 5.15 | Not specified |
| CNA | Linux | Linux | unaffected 5.15 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.267 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.218 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.185 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.154 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.106 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.47 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.11 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.1 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.