ALSA: timer: Forcibly close timer instances at closing

{
  "id": "2b3062b49784275ce1f5b357001fa7096d3f71797b46425a59e32518e86fa2e9",
  "url": "https://osv.dev/vulnerability/CVE-2026-53193",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ALSA: timer: Forcibly close timer instances at closing",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: Forcibly close timer instances at closing When snd_timer object is freed via snd_timer_free() and still pending snd_timer_instance objects are assigned to the timer object, it tries to unlink all instances and just set NULL to each ti->timer, then releases the resources immediately. The problem is, however, when there are slave timer instances that are associated with a master instance linked to this timer: namely, those slave instances still point to the freed timer object although the master instance is unlinked, which may lead to user-after-free. The bug can be easily triggered particularly when a new userspace-driven timers (CONFIG_SND_UTIMER) is involved, since it can create and delete the timer object via a simple file open/close, while the other applications may keep accessing to that timer. This patch is an attempt to paper over the problem above: now instead of just unlinking, call snd_timer_close[_locked]() forcibly for each pending timer instance, so that all assigned slave timer instances are properly detached, too. Since snd_timer_close() might be called later by the driver that created that instance, the check of SNDRV_TIMER_IFLG_DEAD is added at the beginning, too.",
    "evidence": "osv:CVE-2026-53193",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.94",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.36",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.13",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-53193",
      "aliases": [
        "CVE-2026-53193"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                {
                  "fixed": "586b219a22b1032b28b8bd356b963276c5e5bf53"
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                {
                  "fixed": "f46093dd22969037beb1fce2e043f3236be41c92"
                },
                {
                  "fixed": "60e73ab87b84bbd6bd7ddd1d16019a3a3705ab8f"
                },
                {
                  "fixed": "da3039e91d1f835874ed6e9a33ea19ee80c2cb92"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53193.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.12.0"
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                {
                  "fixed": "6.12.94"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.36"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.13"
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              ]
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53193.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.000693182Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/586b219a22b1032b28b8bd356b963276c5e5bf53",
        "https://git.kernel.org/stable/c/60e73ab87b84bbd6bd7ddd1d16019a3a3705ab8f",
        "https://git.kernel.org/stable/c/da3039e91d1f835874ed6e9a33ea19ee80c2cb92",
        "https://git.kernel.org/stable/c/f46093dd22969037beb1fce2e043f3236be41c92",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53193.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53193",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53193.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53193",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493589,
  "published_at": "2026-06-25T08:39:04.346+00:00"
}