{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "030a07e441296c372f946cd4065b5d831d8dc40c"
            },
            {
              "fixed": "64a87950239867682cde128020e1a47088295e5c"
            },
            {
              "fixed": "d9c537b14f4982f17b103e3a2cfeee4bee6bc026"
            },
            {
              "fixed": "0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f"
            },
            {
              "fixed": "71c610aeb1770302ac9c9e0b9a4ecd37f1311928"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.28"
            },
            {
              "fixed": "6.12.111"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97931.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: us122l: Prevent write upgrades for read mappings\n\nThe hwdep mmap callback rejects read-buffer mappings that are initially\nwritable, but leaves VM_MAYWRITE set on mappings created with PROT_READ.\nA process that can open the hwdep node O_RDWR can later use mprotect() to\nmake the mapping writable.\n\nThe read allocation begins with struct usb_stream. Its read_size member is\nused by the fault handler to decide which pages belong to the read buffer.\nThe read VMA intentionally remains expandable because pcm_usb_stream uses\nmremap() after reading that size. Changing read_size first can therefore\nmap and access pages beyond the allocation. The same member is also\nconsumed by usb_stream_free(), where changing it can make\nfree_pages_exact() release pages outside the allocation.\n\nClear VM_MAYWRITE for read-buffer mappings after rejecting an initially\nwritable VMA. This keeps the separate output-buffer mapping writable while\npreventing later permission upgrades.",
  "id": "CVE-2026-97931",
  "modified": "2026-09-27T03:30:44.408696546Z",
  "published": "2026-09-25T10:22:47.382Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d9c537b14f4982f17b103e3a2cfeee4bee6bc026"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97931.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97931"
    },
    {
      "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:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ALSA: us122l: Prevent write upgrades for read mappings"
}