{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab"
            },
            {
              "fixed": "aa3314506deb9703bcf0e889db08959440228fbf"
            },
            {
              "fixed": "90d50648af36a1fbf5dbc99238de6fd0e58a13e0"
            },
            {
              "fixed": "a5dd3d7fba358ff9486f3f51b2a9038348c0970a"
            },
            {
              "fixed": "54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d"
            },
            {
              "fixed": "1d1079db8d1807e259a1d2679ed314949797aad9"
            },
            {
              "fixed": "7087bef6510c7df5df0b19192633b8ecc0f33a6f"
            },
            {
              "fixed": "a636c72c7f522d984fa498fc0631f33a2d0be3fd"
            },
            {
              "fixed": "627a121c15fe05a541f44d86016294b80bada75d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.5.0"
            },
            {
              "fixed": "5.10.270"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.221"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.188"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.51"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89894.json"
  },
  "details": "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'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",
  "modified": "2026-09-18T03:30:46.358485861Z",
  "published": "2026-09-16T10:31:56.101Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1d1079db8d1807e259a1d2679ed314949797aad9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/627a121c15fe05a541f44d86016294b80bada75d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7087bef6510c7df5df0b19192633b8ecc0f33a6f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/90d50648af36a1fbf5dbc99238de6fd0e58a13e0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5dd3d7fba358ff9486f3f51b2a9038348c0970a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a636c72c7f522d984fa498fc0631f33a2d0be3fd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aa3314506deb9703bcf0e889db08959440228fbf"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89894.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89894"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "media: cx231xx: reject geometry changes while the VBI queue is busy"
}