Vulnerability-Lookup

FKIE_CVE-2026-74278

Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:19

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix kernel heap address leak in bounce_error_event() The comment above bounce_error_event() documents that user clients should receive SNDRV_SEQ_EVENT_BOUNCE with the original event embedded as variable-length data, while kernel clients should receive SNDRV_SEQ_EVENT_KERNEL_ERROR with a quoted kernel pointer. However, the implementation unconditionally uses SNDRV_SEQ_EVENT_KERNEL_ERROR with data.quote.event set to the raw struct snd_seq_event pointer for all clients. When a bounce error event is delivered to a USER_CLIENT via snd_seq_read(), the kernel heap address in data.quote.event is exposed to userspace through copy_to_user() in the fixed-length branch. This is a distinct leak path from the one addressed by commit 705dd6dcbc0e ("ALSA: seq: Clear variable event pointer on read"), which sanitizes data.ext.ptr in the variable-length branch of snd_seq_read(). The bounce_error_event() leak uses fixed-length events that take the else branch where no sanitization occurs. Differentiate the bounce event by client type. For USER_CLIENT, send SNDRV_SEQ_EVENT_BOUNCE with SNDRV_SEQ_EVENT_LENGTH_VARIABLE and data.ext pointing to the original event. The variable-length path in snd_seq_event_dup() copies the event data into chained cells, and snd_seq_expand_var_event() copies only the content -- never the pointer -- to userspace. For KERNEL_CLIENT, keep the existing SNDRV_SEQ_EVENT_KERNEL_ERROR behavior with the quoted pointer.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0527a56cb327021cb73167cfddf0e49efa043500
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/93d260ce43a81df579c98bee92b91316df9c1c57
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/dae23c545eb5a2be3b27a82fd0f611894fb8ab69
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/efc86691e4d8083d9e380ea95042c2cf679f65fd

Impacted products

	Vendor	Product	Version

JSON

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": "93d260ce43a81df579c98bee92b91316df9c1c57",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "dae23c545eb5a2be3b27a82fd0f611894fb8ab69",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "0527a56cb327021cb73167cfddf0e49efa043500",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "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": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "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: seq: Fix kernel heap address leak in bounce_error_event()\n\nThe comment above bounce_error_event() documents that user clients\nshould receive SNDRV_SEQ_EVENT_BOUNCE with the original event embedded\nas variable-length data, while kernel clients should receive\nSNDRV_SEQ_EVENT_KERNEL_ERROR with a quoted kernel pointer.\n\nHowever, the implementation unconditionally uses\nSNDRV_SEQ_EVENT_KERNEL_ERROR with data.quote.event set to the raw\nstruct snd_seq_event pointer for all clients.  When a bounce error\nevent is delivered to a USER_CLIENT via snd_seq_read(), the kernel\nheap address in data.quote.event is exposed to userspace through\ncopy_to_user() in the fixed-length branch.\n\nThis is a distinct leak path from the one addressed by commit\n705dd6dcbc0e (\"ALSA: seq: Clear variable event pointer on read\"),\nwhich sanitizes data.ext.ptr in the variable-length branch of\nsnd_seq_read().  The bounce_error_event() leak uses fixed-length\nevents that take the else branch where no sanitization occurs.\n\nDifferentiate the bounce event by client type.  For USER_CLIENT,\nsend SNDRV_SEQ_EVENT_BOUNCE with SNDRV_SEQ_EVENT_LENGTH_VARIABLE\nand data.ext pointing to the original event.  The variable-length\npath in snd_seq_event_dup() copies the event data into chained\ncells, and snd_seq_expand_var_event() copies only the content --\nnever the pointer -- to userspace.  For KERNEL_CLIENT, keep the\nexisting SNDRV_SEQ_EVENT_KERNEL_ERROR behavior with the quoted\npointer."
    }
  ],
  "id": "CVE-2026-74278",
  "lastModified": "2026-08-17T06:19:21.510",
  "metrics": {},
  "published": "2026-08-15T06:22:27.213",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0527a56cb327021cb73167cfddf0e49efa043500"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/93d260ce43a81df579c98bee92b91316df9c1c57"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dae23c545eb5a2be3b27a82fd0f611894fb8ab69"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/efc86691e4d8083d9e380ea95042c2cf679f65fd"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-74278 (GCVE-0-2026-74278)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:57 – Updated: 2026-08-17 05:16

Title

ALSA: seq: Fix kernel heap address leak in bounce_error_event()

Summary

Severity

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/93d260ce43a81df57…
https://git.kernel.org/stable/c/dae23c545eb5a2be3…
https://git.kernel.org/stable/c/0527a56cb327021cb…
https://git.kernel.org/stable/c/efc86691e4d8083d9…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 93d260ce43a81df579c98bee92b91316df9c1c57 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < dae23c545eb5a2be3b27a82fd0f611894fb8ab69 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 0527a56cb327021cb73167cfddf0e49efa043500 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < efc86691e4d8083d9e380ea95042c2cf679f65fd (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "93d260ce43a81df579c98bee92b91316df9c1c57",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "dae23c545eb5a2be3b27a82fd0f611894fb8ab69",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "0527a56cb327021cb73167cfddf0e49efa043500",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "efc86691e4d8083d9e380ea95042c2cf679f65fd",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "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": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Fix kernel heap address leak in bounce_error_event()\n\nThe comment above bounce_error_event() documents that user clients\nshould receive SNDRV_SEQ_EVENT_BOUNCE with the original event embedded\nas variable-length data, while kernel clients should receive\nSNDRV_SEQ_EVENT_KERNEL_ERROR with a quoted kernel pointer.\n\nHowever, the implementation unconditionally uses\nSNDRV_SEQ_EVENT_KERNEL_ERROR with data.quote.event set to the raw\nstruct snd_seq_event pointer for all clients.  When a bounce error\nevent is delivered to a USER_CLIENT via snd_seq_read(), the kernel\nheap address in data.quote.event is exposed to userspace through\ncopy_to_user() in the fixed-length branch.\n\nThis is a distinct leak path from the one addressed by commit\n705dd6dcbc0e (\"ALSA: seq: Clear variable event pointer on read\"),\nwhich sanitizes data.ext.ptr in the variable-length branch of\nsnd_seq_read().  The bounce_error_event() leak uses fixed-length\nevents that take the else branch where no sanitization occurs.\n\nDifferentiate the bounce event by client type.  For USER_CLIENT,\nsend SNDRV_SEQ_EVENT_BOUNCE with SNDRV_SEQ_EVENT_LENGTH_VARIABLE\nand data.ext pointing to the original event.  The variable-length\npath in snd_seq_event_dup() copies the event data into chained\ncells, and snd_seq_expand_var_event() copies only the content --\nnever the pointer -- to userspace.  For KERNEL_CLIENT, keep the\nexisting SNDRV_SEQ_EVENT_KERNEL_ERROR behavior with the quoted\npointer."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:16:23.206Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/93d260ce43a81df579c98bee92b91316df9c1c57"
        },
        {
          "url": "https://git.kernel.org/stable/c/dae23c545eb5a2be3b27a82fd0f611894fb8ab69"
        },
        {
          "url": "https://git.kernel.org/stable/c/0527a56cb327021cb73167cfddf0e49efa043500"
        },
        {
          "url": "https://git.kernel.org/stable/c/efc86691e4d8083d9e380ea95042c2cf679f65fd"
        }
      ],
      "title": "ALSA: seq: Fix kernel heap address leak in bounce_error_event()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74278",
    "datePublished": "2026-08-15T05:57:49.475Z",
    "dateReserved": "2026-08-15T05:44:03.880Z",
    "dateUpdated": "2026-08-17T05:16:23.206Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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