{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "456a8a646b2563438c16a9b27decf9aa717f1ebb"
            },
            {
              "fixed": "e7c99348b0612b2bc02d5ce6ff9873261cc7605f"
            },
            {
              "fixed": "999ca48d55a8a46da21519db7e834e5867200379"
            },
            {
              "fixed": "a025283d7f7404c739225e457fb99db2368bb544"
            },
            {
              "fixed": "54ecdf76a55e75c1f5085e440f8ab671a3283ef5"
            },
            {
              "fixed": "c4e8eaa75fa0b6bcbfa5356d6195c4ad0e05e57a"
            },
            {
              "fixed": "84f8b76d24273175a22713e83e90874e1880d801"
            },
            {
              "fixed": "66b689efd08227da2c5ca49b58b30a95d23c695a"
            },
            {
              "fixed": "b9c310d72783cc2f30d103eed83920a5a29c671a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.4.0"
            },
            {
              "fixed": "5.10.253"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.203"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.168"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.131"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.80"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.21"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31570.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: gw: fix OOB heap access in cgw_csum_crc8_rel()\n\ncgw_csum_crc8_rel() correctly computes bounds-safe indices via calc_idx():\n\n    int from = calc_idx(crc8-\u003efrom_idx, cf-\u003elen);\n    int to   = calc_idx(crc8-\u003eto_idx,   cf-\u003elen);\n    int res  = calc_idx(crc8-\u003eresult_idx, cf-\u003elen);\n\n    if (from \u003c 0 || to \u003c 0 || res \u003c 0)\n        return;\n\nHowever, the loop and the result write then use the raw s8 fields directly\ninstead of the computed variables:\n\n    for (i = crc8-\u003efrom_idx; ...)        /* BUG: raw negative index */\n    cf-\u003edata[crc8-\u003eresult_idx] = ...;    /* BUG: raw negative index */\n\nWith from_idx = to_idx = result_idx = -64 on a 64-byte CAN FD frame,\ncalc_idx(-64, 64) = 0 so the guard passes, but the loop iterates with\ni = -64, reading cf-\u003edata[-64], and the write goes to cf-\u003edata[-64].\nThis write might end up to 56 (7.0-rc) or 40 (\u003c= 6.19) bytes before the\nstart of the canfd_frame on the heap.\n\nThe companion function cgw_csum_xor_rel() uses `from`/`to`/`res`\ncorrectly throughout; fix cgw_csum_crc8_rel() to match.\n\nConfirmed with KASAN on linux-7.0-rc2:\n  BUG: KASAN: slab-out-of-bounds in cgw_csum_crc8_rel+0x515/0x5b0\n  Read of size 1 at addr ffff8880076619c8 by task poc_cgw_oob/62\n\nTo configure the can-gw crc8 checksums CAP_NET_ADMIN is needed.",
  "id": "CVE-2026-31570",
  "modified": "2026-07-08T05:36:41.212231895Z",
  "published": "2026-04-24T14:35:49.435Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/54ecdf76a55e75c1f5085e440f8ab671a3283ef5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/66b689efd08227da2c5ca49b58b30a95d23c695a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/84f8b76d24273175a22713e83e90874e1880d801"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/999ca48d55a8a46da21519db7e834e5867200379"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a025283d7f7404c739225e457fb99db2368bb544"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b9c310d72783cc2f30d103eed83920a5a29c671a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c4e8eaa75fa0b6bcbfa5356d6195c4ad0e05e57a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e7c99348b0612b2bc02d5ce6ff9873261cc7605f"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31570.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31570"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "can: gw: fix OOB heap access in cgw_csum_crc8_rel()"
}