FKIE_CVE-2026-90220

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-17 17:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Don't leak the extension cell pointer in the bounce payload The bounce_error_event() embeds the failed event in the bounce payload by pointing data.ext.ptr at it. When that event is a queued variable-length event, its own data.ext.ptr holds the address of its first extension cell, put there by snd_seq_event_dup(). The payload goes out verbatim through snd_seq_expand_var_event(), so the address reaches userspace. That is the same address commit 705dd6dcbc0e ("ALSA: seq: Clear variable event pointer on read") removed from the event header. The read path still clears it there, just above the call that expands the payload. Embed a sanitised copy instead, treated exactly as snd_seq_read() treats the header. A stack copy is enough because delivery is synchronous and snd_seq_event_dup() copies before returning. An unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE, queueing a variable-length event to a port that does not exist and reading the bounce back. Eight bytes on 64-bit, from its own pool.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/42c3f856d13a91a0d4c302a0c6854813621136db
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/59e1592d3c270ff4642d5d6dc55c545306eb0693
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6e6e471eef1d5d8cb056c7d364023fe048249204
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b1e8d40663997aacaa198f37ce6893e07aaba77a
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/core/seq/seq_clientmgr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "42c3f856d13a91a0d4c302a0c6854813621136db",
              "status": "affected",
              "version": "93d260ce43a81df579c98bee92b91316df9c1c57",
              "versionType": "git"
            },
            {
              "lessThan": "b1e8d40663997aacaa198f37ce6893e07aaba77a",
              "status": "affected",
              "version": "dae23c545eb5a2be3b27a82fd0f611894fb8ab69",
              "versionType": "git"
            },
            {
              "lessThan": "6e6e471eef1d5d8cb056c7d364023fe048249204",
              "status": "affected",
              "version": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
              "versionType": "git"
            },
            {
              "lessThan": "59e1592d3c270ff4642d5d6dc55c545306eb0693",
              "status": "affected",
              "version": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0527a56cb327021cb73167cfddf0e49efa043500",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.110",
              "status": "affected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThan": "6.18.52",
              "status": "affected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThan": "7.2",
              "status": "affected",
              "version": "7.1.5",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/core/seq/seq_clientmgr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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: seq: Don\u0027t leak the extension cell pointer in the bounce payload\n\nThe bounce_error_event() embeds the failed event in the bounce payload\nby pointing data.ext.ptr at it.  When that event is a queued\nvariable-length event, its own data.ext.ptr holds the address of its\nfirst extension cell, put there by snd_seq_event_dup().  The payload\ngoes out verbatim through snd_seq_expand_var_event(), so the address\nreaches userspace.\n\nThat is the same address commit 705dd6dcbc0e (\"ALSA: seq: Clear\nvariable event pointer on read\") removed from the event header.  The\nread path still clears it there, just above the call that expands the\npayload.\n\nEmbed a sanitised copy instead, treated exactly as snd_seq_read()\ntreats the header.  A stack copy is enough because delivery is\nsynchronous and snd_seq_event_dup() copies before returning.\n\nAn unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE,\nqueueing a variable-length event to a port that does not exist and\nreading the bounce back.  Eight bytes on 64-bit, from its own pool."
    }
  ],
  "id": "CVE-2026-90220",
  "lastModified": "2026-09-17T17:17:17.440",
  "metrics": {},
  "published": "2026-09-17T17:17:17.440",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/42c3f856d13a91a0d4c302a0c6854813621136db"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/59e1592d3c270ff4642d5d6dc55c545306eb0693"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6e6e471eef1d5d8cb056c7d364023fe048249204"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b1e8d40663997aacaa198f37ce6893e07aaba77a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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