FKIE_CVE-2026-80578
Vulnerability from fkie_nvd - Published: 2026-08-26 15:17 - Updated: 2026-10-16 20:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
fbdev: core: Fix pointer desynchronization in fb_io_read()
In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to
a faulty user buffer), the loop adjusts the chunk size 'c' and updates
the remaining 'count'. However, the hardware 'src' pointer has already
been eagerly advanced by the original chunk size.
If the loop is allowed to continue, the read will resume from an
incorrect, over-advanced offset. Since the remaining 'count' was only
decremented by the successful bytes, this desynchronization causes the
next iterations to execute more hardware reads than originally bounded,
eventually leading to out-of-bounds I/O reads.
Fix this by breaking out of the loop immediately upon a partial
copy_to_user(). A partial copy indicates a faulty user buffer, making
subsequent read attempts futile. Breaking out ensures we return the
number of successfully read bytes without risking out-of-bounds hardware
accesses in subsequent mismatched iterations.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/video/fbdev/core/fb_io_fops.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "42bc07b4e5a3c8a02a433388f562a8f46d093e11",
"status": "affected",
"version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
"versionType": "git"
},
{
"lessThan": "42a6d8126c194133eafab2b0fd5c8668ebfcba5b",
"status": "affected",
"version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
"versionType": "git"
},
{
"lessThan": "7ff87a01ae3a8cd0208f7499386998223a8b5dba",
"status": "affected",
"version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
"versionType": "git"
},
{
"lessThan": "7110b7b794a2aac2c5cf8eb06ebf2af724c74d50",
"status": "affected",
"version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
"versionType": "git"
},
{
"lessThan": "81cc73be40c6f028f1ee3f438ace46afe666dbae",
"status": "affected",
"version": "6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/video/fbdev/core/fb_io_fops.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.5"
},
{
"lessThan": "6.5",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.153",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.105",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.10",
"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\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 \u0027c\u0027 and updates\nthe remaining \u0027count\u0027. However, the hardware \u0027src\u0027 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 \u0027count\u0027 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."
}
],
"id": "CVE-2026-80578",
"lastModified": "2026-10-16T20:18:01.013",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.3,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.5,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-80578",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-16T19:17:44.203506Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-26T15:17:13.880",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/42a6d8126c194133eafab2b0fd5c8668ebfcba5b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/42bc07b4e5a3c8a02a433388f562a8f46d093e11"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7110b7b794a2aac2c5cf8eb06ebf2af724c74d50"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7ff87a01ae3a8cd0208f7499386998223a8b5dba"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/81cc73be40c6f028f1ee3f438ace46afe666dbae"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.