CVE-2026-64253
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: kernel/fork: clear PF_BLOCK_TS in copy_process() PF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is non-NULL, and blk_finish_plug() clears it via __blk_flush_plug() before NULLing the plug pointer. copy_process() breaks the invariant by inheriting PF_BLOCK_TS from the parent while resetting the child's plug to NULL. Clear PF_BLOCK_TS alongside that assignment so callers can rely on "PF_BLOCK_TS set implies current->plug != NULL" and dereference current->plug unguarded.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-24 16:16:55.017000
Last modified
2026-11-06 17:18:44.167000
View original CVE JSON
{
"id": "CVE-2026-64253",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-07-24T16:16:55.017",
"lastModified": "2026-11-06T17:18:44.167",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkernel/fork: clear PF_BLOCK_TS in copy_process()\n\nPF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is\nnon-NULL, and blk_finish_plug() clears it via __blk_flush_plug()\nbefore NULLing the plug pointer. copy_process() breaks the\ninvariant by inheriting PF_BLOCK_TS from the parent while resetting\nthe child's plug to NULL.\n\nClear PF_BLOCK_TS alongside that assignment so callers can rely on\n\"PF_BLOCK_TS set implies current->plug != NULL\" and dereference\ncurrent->plug unguarded."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"kernel/fork.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "06b23f92af87a84d70881b2ecaa72e00f7838264",
"lessThan": "ee0801aceabdf583392477baf69a290b09448b8f",
"versionType": "git",
"status": "affected"
},
{
"version": "06b23f92af87a84d70881b2ecaa72e00f7838264",
"lessThan": "99e6c712cc300883b8cbf03347d5359ec1a4d6dd",
"versionType": "git",
"status": "affected"
},
{
"version": "06b23f92af87a84d70881b2ecaa72e00f7838264",
"lessThan": "77bba61a20f1b3d206f4f90e10a7bb3cd90b9619",
"versionType": "git",
"status": "affected"
},
{
"version": "06b23f92af87a84d70881b2ecaa72e00f7838264",
"lessThan": "fd38b75c4b43295b10d69772a46d1c74dbd6fc81",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"kernel/fork.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.9",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.9",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.95",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.38",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.3",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T16:33:07.473767Z",
"id": "CVE-2026-64253",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.9",
"versionEndExcluding": "6.12.95",
"matchCriteriaId": "E08F80D6-87F6-4B96-A3A9-F172D7A2E3AA"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.13",
"versionEndExcluding": "6.18.38",
"matchCriteriaId": "FA591B28-5D62-449E-BDBE-3C9391BF070A"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "7.1.3",
"matchCriteriaId": "9526B150-E2B3-4C6F-8AE5-1AF92B75AD9E"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/77bba61a20f1b3d206f4f90e10a7bb3cd90b9619",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/99e6c712cc300883b8cbf03347d5359ec1a4d6dd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/ee0801aceabdf583392477baf69a290b09448b8f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/fd38b75c4b43295b10d69772a46d1c74dbd6fc81",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
}
]
}