{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-80578",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-26T14:34:25.769Z",
        "datePublished": "2026-08-26T14:37:36.722Z",
        "dateUpdated": "2026-08-26T14:37:36.722Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-26T14:37:36.722Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: core: Fix pointer desynchronization in fb_io_read()\n\nIn fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to\na faulty user buffer), the loop adjusts the chunk size 'c' and updates\nthe remaining 'count'. However, the hardware 'src' pointer has already\nbeen eagerly advanced by the original chunk size.\n\nIf the loop is allowed to continue, the read will resume from an\nincorrect, over-advanced offset. Since the remaining 'count' was only\ndecremented by the successful bytes, this desynchronization causes the\nnext iterations to execute more hardware reads than originally bounded,\neventually leading to out-of-bounds I/O reads.\n\nFix this by breaking out of the loop immediately upon a partial\ncopy_to_user(). A partial copy indicates a faulty user buffer, making\nsubsequent read attempts futile. Breaking out ensures we return the\nnumber of successfully read bytes without risking out-of-bounds hardware\naccesses in subsequent mismatched iterations."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/video/fbdev/core/fb_io_fops.c"
                    ],
                    "versions": [
                        {
                            "version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
                            "lessThan": "42bc07b4e5a3c8a02a433388f562a8f46d093e11",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
                            "lessThan": "42a6d8126c194133eafab2b0fd5c8668ebfcba5b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
                            "lessThan": "7ff87a01ae3a8cd0208f7499386998223a8b5dba",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
                            "lessThan": "7110b7b794a2aac2c5cf8eb06ebf2af724c74d50",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
                            "lessThan": "81cc73be40c6f028f1ee3f438ace46afe666dbae",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/video/fbdev/core/fb_io_fops.c"
                    ],
                    "versions": [
                        {
                            "version": "6.5",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.5",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.153",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.105",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.46",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.10",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.5",
                                    "versionEndExcluding": "6.6.153"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.5",
                                    "versionEndExcluding": "6.12.105"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.5",
                                    "versionEndExcluding": "6.18.46"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.5",
                                    "versionEndExcluding": "7.1.10"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.5",
                                    "versionEndExcluding": "7.2"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/42bc07b4e5a3c8a02a433388f562a8f46d093e11"
                },
                {
                    "url": "https://git.kernel.org/stable/c/42a6d8126c194133eafab2b0fd5c8668ebfcba5b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/7ff87a01ae3a8cd0208f7499386998223a8b5dba"
                },
                {
                    "url": "https://git.kernel.org/stable/c/7110b7b794a2aac2c5cf8eb06ebf2af724c74d50"
                },
                {
                    "url": "https://git.kernel.org/stable/c/81cc73be40c6f028f1ee3f438ace46afe666dbae"
                }
            ],
            "title": "fbdev: core: Fix pointer desynchronization in fb_io_read()",
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    }
}