CVE-2026-89894

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89894", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.773Z", "datePublished": "2026-09-16T10:31:56.101Z", "dateUpdated": "2026-10-19T08:54:27.208Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:54:27.208Z"}, "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->width / dev->norm but only refuse the change when the *video* queue\n(dev->vidq) is busy. The VBI queue (dev->vbiq) shares that same geometry:\ncx231xx_init_vbi_isoc() latches dma_q->lines_per_field from dev->norm,\nthe VBI videobuf2 plane is sized from dev->width / dev->norm in\nvbi_queue_setup() and vbi_buf_prepare(), and cx231xx_do_vbi_copy() then\nrecomputes the destination offset from the *live* dev->width and the\nlatched lines_per_field on every URB completion:\n\n\toffset = lines_completed * (dev->width << 1) + ...;\n\tif (dma_q->current_field == 2)\n\t\toffset += dev->width * 2 * dma_q->lines_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->width (or switch dev->norm\nto PAL) through the video node while the VBI stream is running -- the\nchange is allowed because only dev->vidq 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's 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."}], "metrics": [{"cvssV3_1": {"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"}, "scenarios": [{"lang": "en", "value": "AV:L - The overflow is reached only through local V4L2 ioctls (VIDIOC_S_FMT/VIDIOC_S_STD plus REQBUFS/QBUF/STREAMON) on the cx231xx /dev/videoN and /dev/vbiN nodes. A USB capture stick being present is a hardware precondition; the attacker does not inject USB packets, so the path is Local rather than Physical.\nAC:L - The attacker fully controls the sequence: shrink width via VIDIOC_S_FMT, allocate a small VBI plane, STREAMON, then enlarge width or switch standard on the video node while only vidq was checked. Subsequent URB completions copy field-2 VBI with the new geometry into the old plane with no race or layout outside the attacker's control.\nPR:L - cx231xx_v4l2_open(), vidioc_s_fmt_vid_cap(), and vidioc_s_std() perform no capability checks. Triggering the bug needs only an unprivileged local user who can open the V4L2 nodes, which udev grants via the video group and uaccess/logind (or the Android camera context), not init-namespace root.\nUI:N - The attacking process opens /dev/videoN and /dev/vbiN and issues the ioctl sequence itself. No separate victim action such as plugging in a device, mounting a filesystem, or running a privileged helper is required.\nS:U - The out-of-bounds memcpy corrupts kernel vmalloc memory belonging to the same host kernel. Impact is local privilege-escalation or denial of service within one security authority, not a VM escape, IOMMU bypass, or other cross-boundary effect.\nC:H - cx231xx_do_vbi_copy() memcpy()s past the undersized VBI plane at an attacker-chosen offset derived from the new width and latched lines_per_field. That heap out-of-bounds write can smash adjacent vmalloc objects and is leverageable for a kernel read primitive.\nI:H - The same attacker-chosen-offset heap out-of-bounds write overwrites kernel memory after the VBI buffer on every field-2 URB completion. An out-of-bounds write of this form is sufficient for control-flow hijacking and an arbitrary write primitive.\nA:H - memcpy() past the allocated VBI plane faults on a vmalloc guard page or corrupts adjacent kernel memory, producing a kernel oops or panic from URB completion context and taking down the host."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/media/usb/cx231xx/cx231xx-video.c"], "versions": [{"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "aa3314506deb9703bcf0e889db08959440228fbf", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "90d50648af36a1fbf5dbc99238de6fd0e58a13e0", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "a5dd3d7fba358ff9486f3f51b2a9038348c0970a", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "1d1079db8d1807e259a1d2679ed314949797aad9", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "7087bef6510c7df5df0b19192633b8ecc0f33a6f", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "a636c72c7f522d984fa498fc0631f33a2d0be3fd", "status": "affected", "versionType": "git"}, {"version": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab", "lessThan": "627a121c15fe05a541f44d86016294b80bada75d", "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/media/usb/cx231xx/cx231xx-video.c"], "versions": [{"version": "5.5", "status": "affected"}, {"version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "5.5", "versionEndExcluding": "5.10.270"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.15.221"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.1.188"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.12.110"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "6.18.51"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.2.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/aa3314506deb9703bcf0e889db08959440228fbf"}, {"url": "https://git.kernel.org/stable/c/90d50648af36a1fbf5dbc99238de6fd0e58a13e0"}, {"url": "https://git.kernel.org/stable/c/a5dd3d7fba358ff9486f3f51b2a9038348c0970a"}, {"url": "https://git.kernel.org/stable/c/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d"}, {"url": "https://git.kernel.org/stable/c/1d1079db8d1807e259a1d2679ed314949797aad9"}, {"url": "https://git.kernel.org/stable/c/7087bef6510c7df5df0b19192633b8ecc0f33a6f"}, {"url": "https://git.kernel.org/stable/c/a636c72c7f522d984fa498fc0631f33a2d0be3fd"}, {"url": "https://git.kernel.org/stable/c/627a121c15fe05a541f44d86016294b80bada75d"}], "title": "media: cx231xx: reject geometry changes while the VBI queue is busy", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"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", "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->width / dev->norm but only refuse the change when the *video* queue\n(dev->vidq) is busy. The VBI queue (dev->vbiq) shares that same geometry:\ncx231xx_init_vbi_isoc() latches dma_q->lines_per_field from dev->norm,\nthe VBI videobuf2 plane is sized from dev->width / dev->norm in\nvbi_queue_setup() and vbi_buf_prepare(), and cx231xx_do_vbi_copy() then\nrecomputes the destination offset from the *live* dev->width and the\nlatched lines_per_field on every URB completion:\n\n\toffset = lines_completed * (dev->width << 1) + ...;\n\tif (dma_q->current_field == 2)\n\t\toffset += dev->width * 2 * dma_q->lines_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->width (or switch dev->norm\nto PAL) through the video node while the VBI stream is running -- the\nchange is allowed because only dev->vidq 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's 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": "2026-10-19T09:18:34.557", "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"}

{}

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