FKIE_CVE-2026-72142

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-23 13:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: i2c: imx: fix locked bus on SMBus block-read of 0 (atomic) SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the atomic (polling) path rejects it as -EPROTO. Worse, it returns without a NACK+STOP: the next receive cycle has already started, so the target keeps holding SDA and the bus stays stuck until a power cycle for this i2c controller. Reading I2DR to obtain the count likewise arms the next byte on the count > I2C_SMBUS_BLOCK_MAX path, which also returned -EPROTO directly and left the bus held. Handle both: NACK the in-flight dummy byte (TXAK) and extend msgs->len so the existing last-byte handling emits STOP; the dummy byte is discarded. A count of 0 is a valid empty block read; a count above I2C_SMBUS_BLOCK_MAX is still reported as -EPROTO, but only after the bus has been released. The interrupt-driven path has the same flaw from a later commit and is fixed separately, as it carries a different Fixes: tag and stable range.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/016ef0f6ca4bc9bf0330ac41bd2ea349759643e3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0f29df3c3d607a9dbc14aed0e45504ced4d2e7ec
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/38d4947431b2410850409fda016b2ac9f640a4dd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/60ed00d46616a9232e42ea7a3e3c0273d7cf7543
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6d2c973926d0612360693bc559be2ffde836151b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c882e8cc68fb993700dc21fd6e754001e6297934
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cb2fc37857693b55909fb77dc2c87cfbc1cdc476
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e3e8b02d4773cfc5ad561d2e5505efde36c6927a
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/i2c/busses/i2c-imx.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0f29df3c3d607a9dbc14aed0e45504ced4d2e7ec",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "38d4947431b2410850409fda016b2ac9f640a4dd",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "e3e8b02d4773cfc5ad561d2e5505efde36c6927a",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "016ef0f6ca4bc9bf0330ac41bd2ea349759643e3",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "c882e8cc68fb993700dc21fd6e754001e6297934",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "6d2c973926d0612360693bc559be2ffde836151b",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "60ed00d46616a9232e42ea7a3e3c0273d7cf7543",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            },
            {
              "lessThan": "cb2fc37857693b55909fb77dc2c87cfbc1cdc476",
              "status": "affected",
              "version": "8e8782c71595a5ad29e234ce6b3d2fce787fb07a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/i2c/busses/i2c-imx.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.16"
            },
            {
              "lessThan": "3.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.266",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "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": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "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\ni2c: imx: fix locked bus on SMBus block-read of 0 (atomic)\n\nSMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the atomic\n(polling) path rejects it as -EPROTO. Worse, it returns without a\nNACK+STOP: the next receive cycle has already started, so the target\nkeeps holding SDA and the bus stays stuck until a power cycle for\nthis i2c controller.\n\nReading I2DR to obtain the count likewise arms the next byte on the\ncount \u003e I2C_SMBUS_BLOCK_MAX path, which also returned -EPROTO directly\nand left the bus held.\n\nHandle both: NACK the in-flight dummy byte (TXAK) and extend msgs-\u003elen so\nthe existing last-byte handling emits STOP; the dummy byte is discarded.\nA count of 0 is a valid empty block read; a count above\nI2C_SMBUS_BLOCK_MAX is still reported as -EPROTO, but only after the bus\nhas been released.\n\nThe interrupt-driven path has the same flaw from a later commit and is\nfixed separately, as it carries a different Fixes: tag and stable range."
    }
  ],
  "id": "CVE-2026-72142",
  "lastModified": "2026-08-23T13:16:40.440",
  "metrics": {},
  "published": "2026-08-15T06:21:31.827",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/016ef0f6ca4bc9bf0330ac41bd2ea349759643e3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0f29df3c3d607a9dbc14aed0e45504ced4d2e7ec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/38d4947431b2410850409fda016b2ac9f640a4dd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/60ed00d46616a9232e42ea7a3e3c0273d7cf7543"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6d2c973926d0612360693bc559be2ffde836151b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c882e8cc68fb993700dc21fd6e754001e6297934"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cb2fc37857693b55909fb77dc2c87cfbc1cdc476"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e3e8b02d4773cfc5ad561d2e5505efde36c6927a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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