CVE-2026-63960 (GCVE-0-2026-63960)
Vulnerability from cvelistv5
Published
2026-07-19 14:55
Modified
2026-07-20 06:41
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: usb: typec: wcove: don't write past struct pd_message in wcove_read_rx_buffer() wcove_read_rx_buffer() copies the PD RX FIFO into the caller's struct pd_message with for (i = 0; i < USBC_RXINFO_RXBYTES(info); i++) regmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i); which has two problems: USBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message is 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed). The byte count latched in RXINFO is the number of bytes the port partner put on the wire, so a malicious partner that transmits a 31-byte frame can drive the loop one byte past the destination if the WCOVE BMC receiver does not enforce the PD object-count limit in hardware. The existing FIXME flagged this as unverified. Independently, regmap_read() takes an unsigned int * and stores a full unsigned int at the destination. Passing the byte pointer msg + i means each iteration writes four bytes; the high three are zero (val_bits is 8) and are normally overwritten by the next iteration, but the final iteration's high bytes are not. With RXBYTES == 30 the i == 29 iteration already writes three zero bytes past msg, which sits on the IRQ thread's stack in wcove_typec_irq(). Clamp the loop to sizeof(struct pd_message) and read each register into a local before storing only its low byte, so the copy can never exceed the destination regardless of what RXINFO reports.
References
Impacted products
Vendor Product Version
Linux Linux Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
Version: 3c4fb9f169214290ec9a943907321e6265b36f65
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/typec/tcpm/wcove.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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            }
          ]
        },
        {
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          "product": "Linux",
          "programFiles": [
            "drivers/usb/typec/tcpm/wcove.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.15"
            },
            {
              "lessThan": "4.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.259",
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                  "vulnerable": true
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                  "vulnerable": true
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                  "vulnerable": true
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                  "vulnerable": true
                },
                {
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                },
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.12",
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                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "7.1",
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                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: wcove: don\u0027t write past struct pd_message in wcove_read_rx_buffer()\n\nwcove_read_rx_buffer() copies the PD RX FIFO into the caller\u0027s\nstruct pd_message with\n\n\tfor (i = 0; i \u003c USBC_RXINFO_RXBYTES(info); i++)\n\t\tregmap_read(wcove-\u003eregmap, USBC_RX_DATA + i, msg + i);\n\nwhich has two problems:\n\nUSBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message\nis 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed).\nThe byte count latched in RXINFO is the number of bytes the port partner\nput on the wire, so a malicious partner that transmits a 31-byte frame\ncan drive the loop one byte past the destination if the WCOVE BMC\nreceiver does not enforce the PD object-count limit in hardware. The\nexisting FIXME flagged this as unverified.\n\nIndependently, regmap_read() takes an unsigned int * and stores a full\nunsigned int at the destination. Passing the byte pointer msg + i means\neach iteration writes four bytes; the high three are zero (val_bits is\n8) and are normally overwritten by the next iteration, but the final\niteration\u0027s high bytes are not. With RXBYTES == 30 the i == 29 iteration\nalready writes three zero bytes past msg, which sits on the IRQ thread\u0027s\nstack in wcove_typec_irq().\n\nClamp the loop to sizeof(struct pd_message) and read each register into\na local before storing only its low byte, so the copy can never exceed\nthe destination regardless of what RXINFO reports."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T06:41:40.389Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3e632098d0521257ea965bbd6fde807d9bee5c8a"
        },
        {
          "url": "https://git.kernel.org/stable/c/f2a1edc0bd142edabc6c85d88713f2bc178dd317"
        },
        {
          "url": "https://git.kernel.org/stable/c/6899f5b6d7b83ce79a3d331dc61dd31bf73f9c22"
        },
        {
          "url": "https://git.kernel.org/stable/c/5cd0e7ac4eefbdb330f8c72694fe74e63df65552"
        },
        {
          "url": "https://git.kernel.org/stable/c/d0e4b8b3c6b7607a16932556eaaca5d5cf69f192"
        },
        {
          "url": "https://git.kernel.org/stable/c/e94933dc41b87503bf585c8c6d53d740620eceb9"
        },
        {
          "url": "https://git.kernel.org/stable/c/3f9d50c8b02b4af0646aa892465080f9061fc89c"
        },
        {
          "url": "https://git.kernel.org/stable/c/4af7ad0e6d7aa4403dbb1dac7b9659b0421efcaa"
        }
      ],
      "title": "usb: typec: wcove: don\u0027t write past struct pd_message in wcove_read_rx_buffer()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63960",
    "datePublished": "2026-07-19T14:55:50.282Z",
    "dateReserved": "2026-07-19T07:54:57.023Z",
    "dateUpdated": "2026-07-20T06:41:40.389Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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