FKIE_CVE-2026-53193

Vulnerability from fkie_nvd - Published: 2026-06-25 09:16 - Updated: 2026-06-30 14:44
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/586b219a22b1032b28b8bd356b963276c5e5bf53
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/60e73ab87b84bbd6bd7ddd1d16019a3a3705ab8f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/da3039e91d1f835874ed6e9a33ea19ee80c2cb92
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f46093dd22969037beb1fce2e043f3236be41c92
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/core/timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "586b219a22b1032b28b8bd356b963276c5e5bf53",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            },
            {
              "lessThan": "f46093dd22969037beb1fce2e043f3236be41c92",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            },
            {
              "lessThan": "60e73ab87b84bbd6bd7ddd1d16019a3a3705ab8f",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            },
            {
              "lessThan": "da3039e91d1f835874ed6e9a33ea19ee80c2cb92",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/core/timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.94",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.36",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: timer: Forcibly close timer instances at closing\n\nWhen snd_timer object is freed via snd_timer_free() and still pending\nsnd_timer_instance objects are assigned to the timer object, it tries\nto unlink all instances and just set NULL to each ti-\u003etimer, then\nreleases the resources immediately.  The problem is, however, when\nthere are slave timer instances that are associated with a master\ninstance linked to this timer: namely, those slave instances still\npoint to the freed timer object although the master instance is\nunlinked, which may lead to user-after-free.  The bug can be easily\ntriggered particularly when a new userspace-driven timers\n(CONFIG_SND_UTIMER) is involved, since it can create and delete the\ntimer object via a simple file open/close, while the other\napplications may keep accessing to that timer.\n\nThis patch is an attempt to paper over the problem above: now instead\nof just unlinking, call snd_timer_close[_locked]() forcibly for each\npending timer instance, so that all assigned slave timer instances are\nproperly detached, too.  Since snd_timer_close() might be called later\nby the driver that created that instance, the check of\nSNDRV_TIMER_IFLG_DEAD is added at the beginning, too."
    }
  ],
  "id": "CVE-2026-53193",
  "lastModified": "2026-06-30T14:44:27.313",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-25T09:16:36.757",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/586b219a22b1032b28b8bd356b963276c5e5bf53"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/60e73ab87b84bbd6bd7ddd1d16019a3a3705ab8f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/da3039e91d1f835874ed6e9a33ea19ee80c2cb92"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f46093dd22969037beb1fce2e043f3236be41c92"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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