{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "753f1ca4e1e50248a1b760c9774d6d6b354562cc"
            },
            {
              "fixed": "2359264f377cdbdef2d95868cc8fb572949e48d3"
            },
            {
              "fixed": "69a768c12398cada8528080332c822623fa7064d"
            },
            {
              "fixed": "6508304ac2c8cdafca2f4ab915df8c707893e134"
            },
            {
              "fixed": "6cab554f2c0f28773f712ed3a5479103f42ce844"
            },
            {
              "fixed": "0d0845ee61c5df47cc68bc446501f48f71e8dcc6"
            },
            {
              "fixed": "f89416eb3db151170a6f3c6dfc5239d26cdce4d2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.1.189"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.158"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.54"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98368.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nesp: downgrade zerocopy managed frags before mutating skb frags\n\nOn the out-of-place output path (esp-\u003einplace == false) ESP rewrites the\nskb frag array: esp_output_head() appends a trailer frag and\nesp_output_tail() replaces the frags with a destination page, both\nreferenced with get_page().\n\nWhen the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the\npayload frags are owned by the ubuf and must not be referenced or\nunreferenced individually, but ESP mutates the frag array without ever\ndowngrading the skb.  This breaks the managed-frag invariant two ways:\n\n  - esp_ssg_unref() walks the source scatterlist and drops a page\n    reference for every frag, including the ubuf-owned payload frags,\n    pushing their refcount below the GUP pin bias while the pages are\n    still pinned, i.e. a use-after-free of the zerocopy pages;\n\n  - esp_output_tail() installs its destination page as frag 0 with\n    get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so\n    skb_release_data() takes the skip_unref branch and never drops that\n    reference, leaking the x-\u003exfrag page at packet rate.\n\nFix this the way every other frag-mutating site does (__ip_append_data(),\n__ip6_append_data(), tcp_sendmsg_locked()) and call\nskb_zcopy_downgrade_managed() before ESP touches the frag array: it takes\na real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS,\nso the per-frag unref in esp_ssg_unref() and the frag release in\nskb_release_data() are both balanced and no mixed-ownership frag array is\nleft behind.",
  "id": "CVE-2026-98368",
  "modified": "2026-10-08T02:30:44.881612993Z",
  "published": "2026-10-06T08:46:53.292Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98368.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98368"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "esp: downgrade zerocopy managed frags before mutating skb frags"
}