media: cx231xx: reject geometry changes while the VBI queue is busy
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 13 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5, 7.3
Red Hat 3 advisories
- RHSA-2026:89197 Released 2026-10-27 · Red Hat rating CriticalOpenShift Container Platform 4.22.20 bug fix and security update
- Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202610241758-0, rhcos-ppc64le-4.22.9.8.202610241758-0, rhcos-s390x-4.22.9.8.202610241758-0 +1
- RHSA-2026:83207 Released 2026-10-15 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- 10Base-SMTV kernel-modules-internal-6.12.0-211.66.1.el10_2
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.66.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.66.1.el10_2, kernel-64k-devel-6.12.0-211.66.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.66.1.el10_2, kernel-64k-6.12.0-211.66.1.el10_2, kernel-64k-core-6.12.0-211.66.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.66.1.el10_2, libperf-6.12.0-211.66.1.el10_2
- Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.66.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.66.1.el10_2, kernel-rt-64k-6.12.0-211.66.1.el10_2, kernel-rt-64k-core-6.12.0-211.66.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.66.1.el10_2, kernel-rt-core-6.12.0-211.66.1.el10_2, kernel-rt-debug-6.12.0-211.66.1.el10_2 +9
- RHSA-2026:81552 Released 2026-10-13 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.57.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.57.1.el9_8, kernel-64k-devel-5.14.0-687.57.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.57.1.el9_8, kernel-64k-5.14.0-687.57.1.el9_8, kernel-64k-core-5.14.0-687.57.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.57.1.el9_8, libperf-5.14.0-687.57.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.57.1.el9_8, kernel-rt-64k-5.14.0-687.57.1.el9_8, kernel-rt-64k-core-5.14.0-687.57.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.57.1.el9_8, kernel-rt-core-5.14.0-687.57.1.el9_8, kernel-rt-debug-5.14.0-687.57.1.el9_8 +9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
| 10Base-SMTV | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:81552 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:81552 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:81552 |
| Red Hat Enterprise Linux Hidden (v. 10) | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:81552 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:83207 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:81552 |
| Red Hat OpenShift Container Platform 4.22 | Fixed | RHSA-2026:89197 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89894
- 2026-10-03 Alias added: GHSA-c3cf-vcgj-vrgp
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-07 CVSS score added · Red Hat
- 2026-10-13 Fix available: RHSA-2026:81552 · Red Hat
- 2026-10-13 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +2 · Red Hat
- 2026-10-16 Fix available: RHSA-2026:83207 · Red Hat
- 2026-10-16 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +4 · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-28 Fix available: Red Hat OpenShift Container Platform 4.22 · Red Hat
- 2026-10-29 Fix available: RHSA-2026:89197 · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/aa3314506deb9703bcf0e889db08959440228fbf
- https://git.kernel.org/stable/c/90d50648af36a1fbf5dbc99238de6fd0e58a13e0
- https://git.kernel.org/stable/c/a5dd3d7fba358ff9486f3f51b2a9038348c0970a
- https://git.kernel.org/stable/c/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d
- https://git.kernel.org/stable/c/1d1079db8d1807e259a1d2679ed314949797aad9
- https://git.kernel.org/stable/c/7087bef6510c7df5df0b19192633b8ecc0f33a6f
- https://git.kernel.org/stable/c/a636c72c7f522d984fa498fc0631f33a2d0be3fd
- https://git.kernel.org/stable/c/627a121c15fe05a541f44d86016294b80bada75d
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-89894 · CVE Program
- CVE-2026-89894 · NVD
- FIRST EPSS
- GHSA-c3cf-vcgj-vrgp · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89894 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences