FKIE_CVE-2026-68279

Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-19 17:20
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw message and then unconditionally does: memcpy(bytes, &raw->msg[idx], num_bytes); without checking that idx + num_bytes <= raw->curlen. raw->msg[] is 256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger than the remaining payload, the memcpy reads past the received data into whatever follows in raw->msg[]. drm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted with a /* TODO check */ comment since the code was introduced). Fix both functions by using a single combined check (idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8, it is always >= 0, so this strictly subsumes the simpler idx > curlen form and no separate step is needed. [added missing fixes tag]
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/04d953f50d61e542e94a5977822cc53735f8c0ce
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1a8f537f5a1eeac941f262fe73078d6b08ba83c0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/533d9e2bede4aeefdc2a0561d7071cfede95958f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c2fbda0fe0163c55ba3820ee6cea0c6b43622eda
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e6ef5455b06cb4e5d181aabcd723791587c79f12
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/display/drm_dp_mst_topology.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c2fbda0fe0163c55ba3820ee6cea0c6b43622eda",
              "status": "affected",
              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "versionType": "git"
            },
            {
              "lessThan": "22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2",
              "status": "affected",
              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "versionType": "git"
            },
            {
              "lessThan": "04d953f50d61e542e94a5977822cc53735f8c0ce",
              "status": "affected",
              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "versionType": "git"
            },
            {
              "lessThan": "533d9e2bede4aeefdc2a0561d7071cfede95958f",
              "status": "affected",
              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "versionType": "git"
            },
            {
              "lessThan": "e6ef5455b06cb4e5d181aabcd723791587c79f12",
              "status": "affected",
              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "versionType": "git"
            },
            {
              "lessThan": "1a8f537f5a1eeac941f262fe73078d6b08ba83c0",
              "status": "affected",
              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/display/drm_dp_mst_topology.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.17"
            },
            {
              "lessThan": "3.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers\n\ndrm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw\nmessage and then unconditionally does:\n\n  memcpy(bytes, \u0026raw-\u003emsg[idx], num_bytes);\n\nwithout checking that idx + num_bytes \u003c= raw-\u003ecurlen. raw-\u003emsg[] is\n256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger\nthan the remaining payload, the memcpy reads past the received data\ninto whatever follows in raw-\u003emsg[].\n\ndrm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted\nwith a /* TODO check */ comment since the code was introduced).\n\nFix both functions by using a single combined check\n(idx + num_bytes \u003e curlen) before each memcpy. Since num_bytes is u8,\nit is always \u003e= 0, so this strictly subsumes the simpler idx \u003e curlen\nform and no separate step is needed.\n\n[added missing fixes tag]"
    }
  ],
  "id": "CVE-2026-68279",
  "lastModified": "2026-08-19T17:20:40.453",
  "metrics": {},
  "published": "2026-08-10T13:20:17.047",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/04d953f50d61e542e94a5977822cc53735f8c0ce"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1a8f537f5a1eeac941f262fe73078d6b08ba83c0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/533d9e2bede4aeefdc2a0561d7071cfede95958f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c2fbda0fe0163c55ba3820ee6cea0c6b43622eda"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e6ef5455b06cb4e5d181aabcd723791587c79f12"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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