CVE-2026-97931 (GCVE-0-2026-97931)
Vulnerability from cvelistv5
Published
2026-09-25 10:22
Modified
2026-10-19 09:10
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
Impacted products
Vendor Product Version
Linux Linux Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
Version: 030a07e441296c372f946cd4065b5d831d8dc40c
 Create a notification for this product.
Show details on NVD website

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": "cbc1f954ce67d739d41d1f0757d29850353ebb6a",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "becb89036a1320ef0a77da2d27935ac0704345c4",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "6a5f5a5a32c78e67701f1d0f26bc87af68895604",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "lessThan": "938e8d6cee8d36f24669dfdcd3717e081eb32d64",
              "status": "affected",
              "version": "030a07e441296c372f946cd4065b5d831d8dc40c",
              "versionType": "git"
            },
            {
              "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": "5.10.*",
              "status": "unaffected",
              "version": "5.10.271",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.222",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "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",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.271",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.222",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.189",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.158",
                  "versionStartIncluding": "2.6.28",
                  "vulnerable": true
                },
                {
                  "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",
                  "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": "2026-10-19T09:10:58.123Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cbc1f954ce67d739d41d1f0757d29850353ebb6a"
        },
        {
          "url": "https://git.kernel.org/stable/c/becb89036a1320ef0a77da2d27935ac0704345c4"
        },
        {
          "url": "https://git.kernel.org/stable/c/6a5f5a5a32c78e67701f1d0f26bc87af68895604"
        },
        {
          "url": "https://git.kernel.org/stable/c/938e8d6cee8d36f24669dfdcd3717e081eb32d64"
        },
        {
          "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": "2026-10-19T09:10:58.123Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.