FKIE_CVE-2026-74500

Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-17 06:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix stack info leak in RME Digiface status snd_rme_digiface_read_status() reads a four-word status block from the device into an uninitialised on-stack __le32 buf[4] and, whenever the vendor control-IN transfer does not return a negative error, copies all four words into the caller's status[]. snd_usb_ctl_msg() copies the full requested size back into the caller's buffer regardless of how many bytes the data stage actually delivered: buf = kmemdup(data, size, GFP_KERNEL); err = usb_control_msg(dev, pipe, request, requesttype, value, index, buf, size, timeout); memcpy(data, buf, size); usb_control_msg() returns the transferred length on a short control-IN, which is a non-negative value, and writes only that many bytes. The remainder of the copy back is the kmemdup()ed image of the caller's buffer, so a device answering with a short data stage leaves the trailing words of buf[] holding leftover kernel stack. The only guard in the caller is err < 0, so those words are stored into status[]. They then reach user space: snd_rme_digiface_get_status_val() selects a 16-bit halfword of status[] per the control's reg/mask, and the eight Digiface status controls together expose the whole 16-byte frame to an unprivileged reader of /dev/snd/controlC*. Zero-initialise the buffer so a short read yields zeros instead of stack residue. This mirrors snd_rme_get_status1(), which already clears its output word before the same kind of vendor read. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/441aaad150c57edaf57ee482a79a3bf4c5b7e353
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7ba01e0d3539d9cf0aef3e82938f1648147744cc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/98dbfbb38e297c25c5b0af4a9018d71ac25e8554
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b3a346d5c99dd73cf84711f2a43e42691990efd2
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/usb/mixer_quirks.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b3a346d5c99dd73cf84711f2a43e42691990efd2",
              "status": "affected",
              "version": "611a96f6acf2e74fe28cb90908a9c183862348ce",
              "versionType": "git"
            },
            {
              "lessThan": "7ba01e0d3539d9cf0aef3e82938f1648147744cc",
              "status": "affected",
              "version": "611a96f6acf2e74fe28cb90908a9c183862348ce",
              "versionType": "git"
            },
            {
              "lessThan": "98dbfbb38e297c25c5b0af4a9018d71ac25e8554",
              "status": "affected",
              "version": "611a96f6acf2e74fe28cb90908a9c183862348ce",
              "versionType": "git"
            },
            {
              "lessThan": "441aaad150c57edaf57ee482a79a3bf4c5b7e353",
              "status": "affected",
              "version": "611a96f6acf2e74fe28cb90908a9c183862348ce",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3089703ab71484a8b9a7641051181d11d60f870c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "50f63f11a6ddaa0d34574df72b3fa6ee257c057d",
              "versionType": "git"
            },
            {
              "lessThan": "6.11",
              "status": "affected",
              "version": "6.10.14",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12",
              "status": "affected",
              "version": "6.11.3",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/usb/mixer_quirks.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": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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: usb-audio: fix stack info leak in RME Digiface status\n\nsnd_rme_digiface_read_status() reads a four-word status block from the\ndevice into an uninitialised on-stack __le32 buf[4] and, whenever the\nvendor control-IN transfer does not return a negative error, copies all\nfour words into the caller\u0027s status[].\n\nsnd_usb_ctl_msg() copies the full requested size back into the caller\u0027s\nbuffer regardless of how many bytes the data stage actually delivered:\n\n\tbuf = kmemdup(data, size, GFP_KERNEL);\n\terr = usb_control_msg(dev, pipe, request, requesttype,\n\t\t\t      value, index, buf, size, timeout);\n\tmemcpy(data, buf, size);\n\nusb_control_msg() returns the transferred length on a short control-IN,\nwhich is a non-negative value, and writes only that many bytes.  The\nremainder of the copy back is the kmemdup()ed image of the caller\u0027s\nbuffer, so a device answering with a short data stage leaves the\ntrailing words of buf[] holding leftover kernel stack.  The only guard\nin the caller is err \u003c 0, so those words are stored into status[].\n\nThey then reach user space: snd_rme_digiface_get_status_val() selects a\n16-bit halfword of status[] per the control\u0027s reg/mask, and the eight\nDigiface status controls together expose the whole 16-byte frame to an\nunprivileged reader of /dev/snd/controlC*.\n\nZero-initialise the buffer so a short read yields zeros instead of stack\nresidue.  This mirrors snd_rme_get_status1(), which already clears its\noutput word before the same kind of vendor read.\n\nDiscovered by XBOW, triaged by Baul Lee \u003cbaul.lee@xbow.com\u003e"
    }
  ],
  "id": "CVE-2026-74500",
  "lastModified": "2026-08-17T06:19:46.447",
  "metrics": {},
  "published": "2026-08-15T13:17:54.970",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/441aaad150c57edaf57ee482a79a3bf4c5b7e353"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7ba01e0d3539d9cf0aef3e82938f1648147744cc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/98dbfbb38e297c25c5b0af4a9018d71ac25e8554"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b3a346d5c99dd73cf84711f2a43e42691990efd2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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