CVE-2026-93079

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: cxl/features: Reject Get Feature count larger than the output buffer cxlctl_get_feature() sizes its output buffer from the user's fwctl_rpc.out_len, but the device is told to write cxl_mbox_get_feat_in.count bytes into rpc_out->payload, which is a separate user-controlled value. Nothing bounds count against out_len, so a small out_len with a large count overflows the kvzalloc()'d buffer. A heap OOB write reachable from FWCTL_RPC. Reject requests where count exceeds the available payload room, before allocating.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-17 17:18:01.850000

Last modified

2026-10-19 10:16:57.850000

View original CVE JSON

{
  "id": "CVE-2026-93079",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-17T17:18:01.850",
  "lastModified": "2026-10-19T10:16:57.850",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/features: Reject Get Feature count larger than the output buffer\n\ncxlctl_get_feature() sizes its output buffer from the user's\nfwctl_rpc.out_len, but the device is told to write\ncxl_mbox_get_feat_in.count bytes into rpc_out->payload, which is a\nseparate user-controlled value. Nothing bounds count against out_len, so\na small out_len with a large count overflows the kvzalloc()'d buffer.\nA heap OOB write reachable from FWCTL_RPC.\n\nReject requests where count exceeds the available payload room, before\nallocating."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/cxl/core/features.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5908f3ed6dc209e5c824e63afda7545805f75a7e",
              "lessThan": "3f02031a0a53de0d3ef066c92d0486b2b11be40c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5908f3ed6dc209e5c824e63afda7545805f75a7e",
              "lessThan": "329ea475581c647a680a6937e353c1a6e2534b40",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5908f3ed6dc209e5c824e63afda7545805f75a7e",
              "lessThan": "4bf6bac375076ced2fa4b3fef8739bd985f93456",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/cxl/core/features.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.15",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.15",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.52",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.6",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/329ea475581c647a680a6937e353c1a6e2534b40",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3f02031a0a53de0d3ef066c92d0486b2b11be40c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4bf6bac375076ced2fa4b3fef8739bd985f93456",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}