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FKIE_CVE-2026-80792

Vulnerability from fkie_nvd - Published: 2026-09-04 16:18 - Updated: 2026-09-04 16:18
Severity
Summary
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
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/ip6_output.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "75e0a544ebe9af663ef53ca21e9e9185c51fb54a",
              "status": "affected",
              "version": "4132c4ad00ddbf3a175ea0d2c775b662a32f4c85",
              "versionType": "git"
            },
            {
              "lessThan": "c95f01b78266828a57060d754fcbfc92123a98ed",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "d960881b9312e781a3429aabceb223ce6b7c882f",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "087ee0d914aaae929f1660c9ca878e367655ba1a",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "3c770ac4e6f07af7c7b40c474a3efc61ffed7862",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "3dc98e5fe82d069dd29b124ffbdb679331dfea43",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "99219c82804f266189388e8bf1cf5135d10d5515",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "73a187384a8c8b983c7fea046d716b6752a1e7a3",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "lessThan": "d0d48d999b0eee6bb176ef4e39d9be868fa80f7e",
              "status": "affected",
              "version": "e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1598154fd28ffa4a55beae1970475fd6776554b6",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.267",
              "status": "affected",
              "version": "5.10.233",
              "versionType": "semver"
            },
            {
              "lessThan": "5.5",
              "status": "affected",
              "version": "5.4.289",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/ip6_output.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.267",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.218",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.185",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.154",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.106",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.47",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix use-after-free in ip6_finish_output2()\n\nip6_finish_output2() caches a pointer to the IPv6 destination\naddress (daddr) before invoking lwtunnel_xmit().  The LWT-BPF\ntransmit path or other encapsulation operations within\nlwtunnel_xmit() can reallocate the skb head, freeing the memory\nthat daddr points to.  When lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, the function continues to use the stale\ndaddr pointer to compute the nexthop and to look up or create the\nneighbour entry.  This results in a use-after-free read, which can\nleak sensitive kernel data, pollute the neighbour table with\narbitrary values, misdirect traffic, or crash the system.\n\nFix this by re-fetching the IPv6 header and the destination\naddress pointer after lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop\ncomputation and neighbour lookup operate on valid memory."
    }
  ],
  "id": "CVE-2026-80792",
  "lastModified": "2026-09-04T16:18:05.460",
  "metrics": {},
  "published": "2026-09-04T16:18:05.460",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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