CVE-2026-72142
Full vulnerability record from the local CVENow database.
Description
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.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-15 06:21:31.827000
Last modified
2026-11-06 17:19:38.030000
View original CVE JSON
{
"id": "CVE-2026-72142",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-15T06:21:31.827",
"lastModified": "2026-11-06T17:19:38.030",
"vulnStatus": "Received",
"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 > 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->len 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."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/i2c/busses/i2c-imx.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
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"versionType": "git",
"status": "affected"
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"status": "affected"
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.16",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.16",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.266",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.217",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.184",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.148",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.101",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.40",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.5",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T16:51:58.347338Z",
"id": "CVE-2026-72142",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
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