GHSA-5XGR-HPWF-WCM3

Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-19 18:32
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

media: vivid: check for vb2_is_busy() when toggling caps

The vivid_update_format_cap/out() functions must only be called if the capture/output queue are not busy. But for the controls that select the CROP/COMPOSE/SCALE capability that is not checked.

Only when streaming starts will they be set to 'grabbed' and it is impossible to change the control, but between REQBUFS and STREAMON you are still allowed to set these controls. Since vivid_update_format_cap/out will change the format, this can cause unexpected results.

Besides adding these checks, also add a WARN_ON in vivid_update_format_cap/out() if the queue is busy.

I'm 90% certain that this is the cause of this syzbot bug:

https://syzkaller.appspot.com/bug?extid=dac8f5eaa46837e97b89

But since we never have reproducers, it is hard to be certain. In any case, these checks are needed regardless.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-68204"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T13:20:08Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: vivid: check for vb2_is_busy() when toggling caps\n\nThe vivid_update_format_cap/out() functions must only be called if the\ncapture/output queue are not busy. But for the controls that select\nthe CROP/COMPOSE/SCALE capability that is not checked.\n\nOnly when streaming starts will they be set to \u0027grabbed\u0027 and it is\nimpossible to change the control, but between REQBUFS and STREAMON you\nare still allowed to set these controls. Since vivid_update_format_cap/out\nwill change the format, this can cause unexpected results.\n\nBesides adding these checks, also add a WARN_ON in\nvivid_update_format_cap/out() if the queue is busy.\n\nI\u0027m 90% certain that this is the cause of this syzbot bug:\n\nhttps://syzkaller.appspot.com/bug?extid=dac8f5eaa46837e97b89\n\nBut since we never have reproducers, it is hard to be certain. In any case,\nthese checks are needed regardless.",
  "id": "GHSA-5xgr-hpwf-wcm3",
  "modified": "2026-08-19T18:32:10Z",
  "published": "2026-08-10T15:33:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68204"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0a820f03727b509b887f3216a574062948761f34"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/492c97cb50feaa60ccd7792d3d6b904ed8ec61bf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6a5bc8aea111ccbca71ef2b9c868d5c81f2e89de"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a9cd0e8fb0b21faaa71199d9d3feb305c18ff576"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/abaec6747304581f8d4a9936352fa10e13325f07"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bbc96bc75de0fcd9bb6ac48798b206e3b09ec865"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c2d1a2130c93f6d758af58590b86b2254c7a1dec"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/daf2d92669b4a659d805d88d811161c70cd325ee"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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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.

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