Vulnerability-Lookup

FKIE_CVE-2026-97931

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-09-25 15:18

Severity

7.0 (High) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: ALSA: us122l: Prevent write upgrades for read mappings The hwdep mmap callback rejects read-buffer mappings that are initially writable, but leaves VM_MAYWRITE set on mappings created with PROT_READ. A process that can open the hwdep node O_RDWR can later use mprotect() to make the mapping writable. The read allocation begins with struct usb_stream. Its read_size member is used by the fault handler to decide which pages belong to the read buffer. The read VMA intentionally remains expandable because pcm_usb_stream uses mremap() after reading that size. Changing read_size first can therefore map and access pages beyond the allocation. The same member is also consumed by usb_stream_free(), where changing it can make free_pages_exact() release pages outside the allocation. Clear VM_MAYWRITE for read-buffer mappings after rejecting an initially writable VMA. This keeps the separate output-buffer mapping writable while preventing later permission upgrades.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d9c537b14f4982f17b103e3a2cfeee4bee6bc026

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/usb/usx2y/us122l.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "64a87950239867682cde128020e1a47088295e5c",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "d9c537b14f4982f17b103e3a2cfeee4bee6bc026",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "71c610aeb1770302ac9c9e0b9a4ecd37f1311928",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/usb/usx2y/us122l.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.28"
            },
            {
              "lessThan": "2.6.28",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "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: us122l: Prevent write upgrades for read mappings\n\nThe hwdep mmap callback rejects read-buffer mappings that are initially\nwritable, but leaves VM_MAYWRITE set on mappings created with PROT_READ.\nA process that can open the hwdep node O_RDWR can later use mprotect() to\nmake the mapping writable.\n\nThe read allocation begins with struct usb_stream. Its read_size member is\nused by the fault handler to decide which pages belong to the read buffer.\nThe read VMA intentionally remains expandable because pcm_usb_stream uses\nmremap() after reading that size. Changing read_size first can therefore\nmap and access pages beyond the allocation. The same member is also\nconsumed by usb_stream_free(), where changing it can make\nfree_pages_exact() release pages outside the allocation.\n\nClear VM_MAYWRITE for read-buffer mappings after rejecting an initially\nwritable VMA. This keeps the separate output-buffer mapping writable while\npreventing later permission upgrades."
    }
  ],
  "id": "CVE-2026-97931",
  "lastModified": "2026-09-25T15:18:02.450",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-25T11:17:20.387",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d9c537b14f4982f17b103e3a2cfeee4bee6bc026"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-97931 (GCVE-0-2026-97931)

Vulnerability from cvelistv5 – Published: 2026-09-25 10:22 – Updated: 2026-09-25 14:41

Title

ALSA: us122l: Prevent write upgrades for read mappings

Summary

Severity

7 (High)


                        
                          CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/64a87950239867682…
https://git.kernel.org/stable/c/d9c537b14f4982f17…
https://git.kernel.org/stable/c/0eb9dd4774af0ac4d…
https://git.kernel.org/stable/c/71c610aeb1770302a…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 030a07e441296c372f946cd4065b5d831d8dc40c , < 64a87950239867682cde128020e1a47088295e5c (git) Affected: 030a07e441296c372f946cd4065b5d831d8dc40c , < d9c537b14f4982f17b103e3a2cfeee4bee6bc026 (git) Affected: 030a07e441296c372f946cd4065b5d831d8dc40c , < 0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f (git) Affected: 030a07e441296c372f946cd4065b5d831d8dc40c , < 71c610aeb1770302ac9c9e0b9a4ecd37f1311928 (git)
Linux	Linux	Affected: 2.6.28 Unaffected: 0 , < 2.6.28 (semver) Unaffected: 6.12.111 , ≤ 6.12.* (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2.7 , ≤ 7.2.* (semver) Unaffected: 7.3-rc3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/usb/usx2y/us122l.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "64a87950239867682cde128020e1a47088295e5c",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "d9c537b14f4982f17b103e3a2cfeee4bee6bc026",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "71c610aeb1770302ac9c9e0b9a4ecd37f1311928",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/usb/usx2y/us122l.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.28"
            },
            {
              "lessThan": "2.6.28",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.7",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc3",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: us122l: Prevent write upgrades for read mappings\n\nThe hwdep mmap callback rejects read-buffer mappings that are initially\nwritable, but leaves VM_MAYWRITE set on mappings created with PROT_READ.\nA process that can open the hwdep node O_RDWR can later use mprotect() to\nmake the mapping writable.\n\nThe read allocation begins with struct usb_stream. Its read_size member is\nused by the fault handler to decide which pages belong to the read buffer.\nThe read VMA intentionally remains expandable because pcm_usb_stream uses\nmremap() after reading that size. Changing read_size first can therefore\nmap and access pages beyond the allocation. The same member is also\nconsumed by usb_stream_free(), where changing it can make\nfree_pages_exact() release pages outside the allocation.\n\nClear VM_MAYWRITE for read-buffer mappings after rejecting an initially\nwritable VMA. This keeps the separate output-buffer mapping writable while\npreventing later permission upgrades."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bad data is written by a local process. It maps the us122l hwdep read buffer PROT_READ via usb_stream_hwdep_mmap(), upgrades it with mprotect() because VM_MAYWRITE was never cleared, and overwrites usb_stream.read_size. No remote protocol or USB packet carries the malicious value.\nAC:H - The driver only binds, and only creates /dev/snd/hwC*D*, when a TASCAM US-122L/US-144 is attached. A local attacker can\u0027t produce that hardware without physical access. Once it is present, mmap, mprotect, a read_size overwrite and mremap are fully deterministic.\nPR:L - The attacker needs an O_RDWR open of the hwdep node, which a normal user gets through audio group or seat uaccess ACLs. usb_stream_hwdep_open() and usb_stream_hwdep_ioctl() do no capability checks, and the stream already exists from probe.\nUI:N - The attacker\u0027s own process does the open, mmap, mprotect, write to read_size, mremap and page faults. No other user has to act.\nS:U - The result is corrupted kernel memory and local privilege escalation within the same kernel authority. No VM or hardware isolation boundary is crossed.\nC:H - With an inflated read_size, usb_stream_hwdep_vm_fault() maps virt_to_page((char *)s + offset) for offsets past the alloc_pages_exact() buffer. Userspace can then directly read arbitrary adjacent kernel pages.\nI:H - Those out-of-bounds pages are mapped writable into userspace, giving direct write access to kernel memory. In addition, usb_stream_free() calls free_pages_exact(s, read_size) with the tampered size, freeing pages that are still in use, a page-level use-after-free.\nA:H - Writing to foreign kernel pages, or freeing the wrong pages through usb_stream_free() on SET_PARAMS re-init or disconnect, corrupts the page allocator and kernel data, which leads to an oops or panic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-25T14:41:39.476Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/64a87950239867682cde128020e1a47088295e5c"
        },
        {
          "url": "https://git.kernel.org/stable/c/d9c537b14f4982f17b103e3a2cfeee4bee6bc026"
        },
        {
          "url": "https://git.kernel.org/stable/c/0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f"
        },
        {
          "url": "https://git.kernel.org/stable/c/71c610aeb1770302ac9c9e0b9a4ecd37f1311928"
        }
      ],
      "title": "ALSA: us122l: Prevent write upgrades for read mappings",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-97931",
    "datePublished": "2026-09-25T10:22:47.382Z",
    "dateReserved": "2026-09-25T10:18:58.203Z",
    "dateUpdated": "2026-09-25T14:41:39.476Z",
    "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.

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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FKIE_CVE-2026-97931

CVE-2026-97931 (GCVE-0-2026-97931)

Tags

Sightings

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