{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "f748be531d7012c456b97f66091d86b3675c5fef"
            },
            {
              "fixed": "ffa6d2481bc1c87f822ecd626561484e4ee24cef"
            },
            {
              "fixed": "c28175220f808c867d5618de8ecc6dbcc815c773"
            },
            {
              "fixed": "65820fc743eae322f7f94f6a64d07861211d4b21"
            },
            {
              "fixed": "5e38d732ec67a5b1f9a56e6c73add480c4b6030a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.7.0"
            },
            {
              "fixed": "6.12.111"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97953.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: fix TX descriptor availability check for TSO traffic\n\nstmmac_tso_xmit() estimates the number of free TX descriptors required by\na TSO skb as:\n\n\t(skb-\u003elen - proto_hdr_len) / TSO_MAX_BUFF_SIZE + 1\n\nwhich assumes the payload is split into TSO_MAX_BUFF_SIZE chunks. This\nunderestimates the descriptors actually consumed by stmmac_tso_allocator(),\nsince each fragment is mapped individually and so it needs at least one\ndescriptor regardless of its size. Moreover, one descriptor is used for\nthe L2/L3/L4 headers and, when the MSS changes, one more is consumed for\nthe MSS context descriptor.\nFor a highly fragmented TSO skb the check can therefore pass even when the\nring has too few free slots. stmmac_tso_allocator() then writes past the\navailable descriptors, overwriting descriptors still owned by the DMA\nengine, corrupting the TX ring.\nAdd stmmac_tso_get_num_desc() to compute the exact number of descriptors\nneeded for the header, the linear payload and each fragment, plus the MSS\ncontext descriptor when required, and use it in the availability check.",
  "id": "CVE-2026-97953",
  "modified": "2026-09-27T03:30:47.072633981Z",
  "published": "2026-09-25T10:23:00.758Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e38d732ec67a5b1f9a56e6c73add480c4b6030a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/65820fc743eae322f7f94f6a64d07861211d4b21"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c28175220f808c867d5618de8ecc6dbcc815c773"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ffa6d2481bc1c87f822ecd626561484e4ee24cef"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97953.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97953"
    },
    {
      "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:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "net: stmmac: fix TX descriptor availability check for TSO traffic"
}