CVE-2026-98027

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

• https://git.kernel.org/stable/c/44cd4674d9aa5bdf793b8a8b481c9e8536ed6070 416baaa9-dc9f-4396-8d5f-8c081fb06d67
• https://git.kernel.org/stable/c/7a683c2b062810bca203e41866389daf387c235b 416baaa9-dc9f-4396-8d5f-8c081fb06d67
• https://git.kernel.org/stable/c/b1fffc273112e7284c5b705e186b43b5770cd3d5 416baaa9-dc9f-4396-8d5f-8c081fb06d67
• https://git.kernel.org/stable/c/cda5ac8fe8ac8e80b1703ebb8c4250726fc19739 416baaa9-dc9f-4396-8d5f-8c081fb06d67

The full cvelistV5 record. Download as CVE-2026-98027.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/dsa/mv88e6xxx/chip.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "44cd4674d9aa5bdf793b8a8b481c9e8536ed6070",
              "status": "affected",
              "version": "da7dc87553046a43be1620a783ce3d9f6583d322",
              "versionType": "git"
            },
            {
              "lessThan": "7a683c2b062810bca203e41866389daf387c235b",
              "status": "affected",
              "version": "da7dc87553046a43be1620a783ce3d9f6583d322",
              "versionType": "git"
            },
            {
              "lessThan": "cda5ac8fe8ac8e80b1703ebb8c4250726fc19739",
              "status": "affected",
              "version": "da7dc87553046a43be1620a783ce3d9f6583d322",
              "versionType": "git"
            },
            {
              "lessThan": "b1fffc273112e7284c5b705e186b43b5770cd3d5",
              "status": "affected",
              "version": "da7dc87553046a43be1620a783ce3d9f6583d322",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/dsa/mv88e6xxx/chip.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.4"
            },
            {
              "lessThan": "5.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.7",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc3",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size\n\nmv88e6xxx_get_rxnfc() uses rxnfc->rule_cnt as the write index while\ndumping the policy IDR, clobbering the input value before it has been\nlooked at.  That input is the number of entries the caller had room for.\nETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the\nbuffer from the rule_cnt userspace passes in, so once an admin has\ninstalled policy rules any user can ask for fewer slots than there are\nrules and run off the end of the allocation.  A rule_cnt of 0 leaves the\nbuffer pointer NULL and the walk dereferences it.\n\nCount into a local so the caller's limit survives the walk, and stop with\n-EMSGSIZE once it is reached."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The overflow is reached only through the local SIOCETHTOOL ioctl: dev_ethtool() -> ethtool_get_rxnfc() -> dsa_user_get_rxnfc() -> mv88e6xxx_get_rxnfc(ETHTOOL_GRXCLSRLALL). The bad input is the rule_cnt field of the ethtool_rxnfc struct the user passes in. No network packet reaches this path.\nAC:H - The OOB write only happens if policy rules already exist in chip->policies for that DSA port. Those are installed by an admin via ETHTOOL_SRXCLSRLINS, which needs CAP_NET_ADMIN over the hardware port. The attacker can't create that state. Once rules exist, a small rule_cnt triggers it deterministically.\nPR:L - dev_ethtool() lists ETHTOOL_GRXCLSRLALL among the commands exempt from the ns_capable(CAP_NET_ADMIN) check. Any unprivileged local user who can see the mv88e6xxx user port in their netns can issue the ioctl.\nUI:N - The attacker makes the ioctl call and picks rule_cnt themselves. No other user has to do anything.\nS:U - The corruption hits the kernel heap in the same kernel that runs the attacker's ioctl. No VM, IOMMU or other authority boundary is crossed.\nC:H - ethtool_get_rxnfc() sizes rule_buf with kcalloc(rule_cnt, 4) from the user's value. The driver then overwrites rxnfc->rule_cnt with the real rule count, so ethtool_rxnfc_copy_to_user() copies that many u32s from the undersized buffer, reading past the slab object into userspace. The same heap corruption can also be groomed to leak more.\nI:H - mv88e6xxx_get_rxnfc() writes rule_locs[rxnfc->rule_cnt++] = id for every rule on the port with no bound, so u32 IDs go past a kmalloc object whose size and cache the attacker chose via rule_cnt. That heap OOB write can corrupt neighbouring objects.\nA:H - With rule_cnt=0, ethtool_get_rxnfc() passes a NULL rule_buf and the IDR walk writes through it, oopsing the kernel on demand. Larger overflows corrupt slab memory and can panic the system. Either can be repeated."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-25T14:41:52.813Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/44cd4674d9aa5bdf793b8a8b481c9e8536ed6070"
        },
        {
          "url": "https://git.kernel.org/stable/c/7a683c2b062810bca203e41866389daf387c235b"
        },
        {
          "url": "https://git.kernel.org/stable/c/cda5ac8fe8ac8e80b1703ebb8c4250726fc19739"
        },
        {
          "url": "https://git.kernel.org/stable/c/b1fffc273112e7284c5b705e186b43b5770cd3d5"
        }
      ],
      "title": "net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98027",
    "datePublished": "2026-09-25T10:23:45.123Z",
    "dateReserved": "2026-09-25T10:19:56.070Z",
    "dateUpdated": "2026-09-25T14:41:52.813Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}