CVE-2026-64036
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: cgroup/rstat: validate cpu before css_rstat_cpu() access css_rstat_updated() is exposed as a BPF kfunc and accepts a caller-provided cpu argument. The function uses cpu for per-cpu rstat lookups without checking whether it refers to a valid possible CPU. A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu == 0x7fffffff triggers: UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9 index 2147483647 is out of range for type 'long unsigned int [64]' Call Trace: css_rstat_updated bpf_iter_run_prog cgroup_iter_seq_show bpf_seq_read Add cpu validation to the BPF-facing css_rstat_updated() kfunc and move the common implementation to __css_rstat_updated() for in-kernel callers.
Severity
HIGH
CVSS score
7.8
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 16:17:43.847000
Last modified
2026-10-30 13:19:29.250000
View original CVE JSON
{
"id": "CVE-2026-64036",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-07-19T16:17:43.847",
"lastModified": "2026-10-30T13:19:29.250",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/rstat: validate cpu before css_rstat_cpu() access\n\ncss_rstat_updated() is exposed as a BPF kfunc and accepts a\ncaller-provided cpu argument. The function uses cpu for per-cpu rstat\nlookups without checking whether it refers to a valid possible CPU.\n\nA BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an\ninvalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==\n0x7fffffff triggers:\n\n UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9\n index 2147483647 is out of range for type 'long unsigned int [64]'\n Call Trace:\n css_rstat_updated\n bpf_iter_run_prog\n cgroup_iter_seq_show\n bpf_seq_read\n\nAdd cpu validation to the BPF-facing css_rstat_updated() kfunc and\nmove the common implementation to __css_rstat_updated() for in-kernel\ncallers."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"block/blk-cgroup.c",
"include/linux/cgroup.h",
"kernel/cgroup/rstat.c",
"mm/memcontrol.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "ee5afb74688aa6f1f16d8c7e7b6bfaf803fb62fc",
"versionType": "git",
"status": "affected"
},
{
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "b28b862b07257219755d0b0a7fbe5d23b7c9ea91",
"versionType": "git",
"status": "affected"
},
{
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "3d595affbe00a2e8bf43b9f2947a8efcdc1c059e",
"versionType": "git",
"status": "affected"
},
{
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6",
"versionType": "git",
"status": "affected"
},
{
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "fd2bd9fa7700ddf28296486b2598cff2f80cc819",
"versionType": "git",
"status": "affected"
},
{
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "8817005efbdfdf5d4e4814cb5dc52b53d12917d7",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"block/blk-cgroup.c",
"include/linux/cgroup.h",
"kernel/cgroup/rstat.c",
"mm/memcontrol.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.1",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.1",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.114",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.34",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.0.11",
"lessThanOrEqual": "7.0.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T15:35:47.371867Z",
"id": "CVE-2026-64036",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-129"
}
]
},
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-125"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.1",
"versionEndExcluding": "6.18.34",
"matchCriteriaId": "3AFEE574-58CB-4E6A-967F-E74EA0FF1F9F"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19",
"versionEndExcluding": "7.0.11",
"matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
"matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
"matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
"matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
"matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/3d595affbe00a2e8bf43b9f2947a8efcdc1c059e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/8817005efbdfdf5d4e4814cb5dc52b53d12917d7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/b28b862b07257219755d0b0a7fbe5d23b7c9ea91",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ee5afb74688aa6f1f16d8c7e7b6bfaf803fb62fc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fd2bd9fa7700ddf28296486b2598cff2f80cc819",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
}
]
}