FKIE_CVE-2026-89894
Vulnerability from fkie_nvd - Published: 2026-09-16 11:16 - Updated: 2026-09-16 15:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
media: cx231xx: reject geometry changes while the VBI queue is busy
vidioc_s_fmt_vid_cap() and vidioc_s_std() change the device-wide
dev->width / dev->norm but only refuse the change when the *video* queue
(dev->vidq) is busy. The VBI queue (dev->vbiq) shares that same geometry:
cx231xx_init_vbi_isoc() latches dma_q->lines_per_field from dev->norm,
the VBI videobuf2 plane is sized from dev->width / dev->norm in
vbi_queue_setup() and vbi_buf_prepare(), and cx231xx_do_vbi_copy() then
recomputes the destination offset from the *live* dev->width and the
latched lines_per_field on every URB completion:
offset = lines_completed * (dev->width << 1) + ...;
if (dma_q->current_field == 2)
offset += dev->width * 2 * dma_q->lines_per_field;
memcpy(plane + offset, p_buffer, lencopy);
Because the VBI node shares video_ioctl_ops with the video node, an
application can size a small VBI plane (REQBUFS/QBUF with a small width,
or with the NTSC standard), then enlarge dev->width (or switch dev->norm
to PAL) through the video node while the VBI stream is running -- the
change is allowed because only dev->vidq is checked -- and let the device
deliver a field-2 VBI payload. cx231xx_do_vbi_copy() now computes the
offset with the larger geometry and memcpy()s past the end of the smaller
plane that was already allocated, a heap out-of-bounds write whose offset
is attacker-chosen and whose contents come from the device. The
per-field guard in cx231xx_copy_vbi_line() does not help: it bounds the
copy against the latched lines_per_field, not the plane's real capacity,
and vb2 does not re-run buf_prepare() for an already prepared buffer.
Refuse the format/standard change when the VBI queue is busy as well, so
the geometry cannot change underneath an allocated VBI buffer.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/media/usb/cx231xx/cx231xx-video.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "aa3314506deb9703bcf0e889db08959440228fbf",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "90d50648af36a1fbf5dbc99238de6fd0e58a13e0",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "a5dd3d7fba358ff9486f3f51b2a9038348c0970a",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "1d1079db8d1807e259a1d2679ed314949797aad9",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "7087bef6510c7df5df0b19192633b8ecc0f33a6f",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "a636c72c7f522d984fa498fc0631f33a2d0be3fd",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
},
{
"lessThan": "627a121c15fe05a541f44d86016294b80bada75d",
"status": "affected",
"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/media/usb/cx231xx/cx231xx-video.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.5"
},
{
"lessThan": "5.5",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"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\nmedia: cx231xx: reject geometry changes while the VBI queue is busy\n\nvidioc_s_fmt_vid_cap() and vidioc_s_std() change the device-wide\ndev-\u003ewidth / dev-\u003enorm but only refuse the change when the *video* queue\n(dev-\u003evidq) is busy. The VBI queue (dev-\u003evbiq) shares that same geometry:\ncx231xx_init_vbi_isoc() latches dma_q-\u003elines_per_field from dev-\u003enorm,\nthe VBI videobuf2 plane is sized from dev-\u003ewidth / dev-\u003enorm in\nvbi_queue_setup() and vbi_buf_prepare(), and cx231xx_do_vbi_copy() then\nrecomputes the destination offset from the *live* dev-\u003ewidth and the\nlatched lines_per_field on every URB completion:\n\n\toffset = lines_completed * (dev-\u003ewidth \u003c\u003c 1) + ...;\n\tif (dma_q-\u003ecurrent_field == 2)\n\t\toffset += dev-\u003ewidth * 2 * dma_q-\u003elines_per_field;\n\tmemcpy(plane + offset, p_buffer, lencopy);\n\nBecause the VBI node shares video_ioctl_ops with the video node, an\napplication can size a small VBI plane (REQBUFS/QBUF with a small width,\nor with the NTSC standard), then enlarge dev-\u003ewidth (or switch dev-\u003enorm\nto PAL) through the video node while the VBI stream is running -- the\nchange is allowed because only dev-\u003evidq is checked -- and let the device\ndeliver a field-2 VBI payload. cx231xx_do_vbi_copy() now computes the\noffset with the larger geometry and memcpy()s past the end of the smaller\nplane that was already allocated, a heap out-of-bounds write whose offset\nis attacker-chosen and whose contents come from the device. The\nper-field guard in cx231xx_copy_vbi_line() does not help: it bounds the\ncopy against the latched lines_per_field, not the plane\u0027s real capacity,\nand vb2 does not re-run buf_prepare() for an already prepared buffer.\n\nRefuse the format/standard change when the VBI queue is busy as well, so\nthe geometry cannot change underneath an allocated VBI buffer."
}
],
"id": "CVE-2026-89894",
"lastModified": "2026-09-16T15:18:15.790",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-09-16T11:16:58.127",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1d1079db8d1807e259a1d2679ed314949797aad9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/627a121c15fe05a541f44d86016294b80bada75d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7087bef6510c7df5df0b19192633b8ecc0f33a6f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/90d50648af36a1fbf5dbc99238de6fd0e58a13e0"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a5dd3d7fba358ff9486f3f51b2a9038348c0970a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a636c72c7f522d984fa498fc0631f33a2d0be3fd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/aa3314506deb9703bcf0e889db08959440228fbf"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
Loading…
Loading…
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.
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.
Loading…