Vulnerability-Lookup

FKIE_CVE-2026-89942

Vulnerability from fkie_nvd - Published: 2026-09-16 11:17 - Updated: 2026-09-16 15:18

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix potential use-after-free in anonymous buffer release An anonymous buffer handle holds a reference to the underlying IIO device. The reference is dropped in the buffer handle's release function. If the device has been removed, either through unbind or hot-unplug, the buffer handle might hold the last reference. The release function takes the mutex for the buffer using a guard, which means the unlock happens after all the code in the function, including `iio_device_put()`. If the anonymous buffer holds the last reference this might free both the IIO device and the buffer, which contains the mutex, leading to use-after-free when the mutex is unlocked. Fix this by using a scoped guard just around the buffer dmabuf list access, making sure the mutex is unlocked before releasing the IIO device. Version 10 of the patch that introduced this issue used this exact scheme of first unlocking and then dropping the reference [1]. During review it was suggested to use a guard instead, and version 11 made that change [2].

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6288b593e76eb10329326f2cd51e32557203b9e5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6d4bdbf7bad63e759bf20259c527f69a1209e3dd
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ab53077511cde811bf3ee219426c522329c41226
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f1f8f0e8e0af9cae8150658dc7bb51332f984893

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iio/industrialio-buffer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ab53077511cde811bf3ee219426c522329c41226",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            },
            {
              "lessThan": "f1f8f0e8e0af9cae8150658dc7bb51332f984893",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            },
            {
              "lessThan": "6d4bdbf7bad63e759bf20259c527f69a1209e3dd",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            },
            {
              "lessThan": "6288b593e76eb10329326f2cd51e32557203b9e5",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iio/industrialio-buffer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "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\niio: buffer: Fix potential use-after-free in anonymous buffer release\n\nAn anonymous buffer handle holds a reference to the underlying IIO device.\nThe reference is dropped in the buffer handle\u0027s release function. If the\ndevice has been removed, either through unbind or hot-unplug, the buffer\nhandle might hold the last reference.\n\nThe release function takes the mutex for the buffer using a guard, which\nmeans the unlock happens after all the code in the function, including\n`iio_device_put()`. If the anonymous buffer holds the last reference this\nmight free both the IIO device and the buffer, which contains the mutex,\nleading to use-after-free when the mutex is unlocked.\n\nFix this by using a scoped guard just around the buffer dmabuf list access,\nmaking sure the mutex is unlocked before releasing the IIO device.\n\nVersion 10 of the patch that introduced this issue used this exact scheme\nof first unlocking and then dropping the reference [1]. During review it\nwas suggested to use a guard instead, and version 11 made that change [2]."
    }
  ],
  "id": "CVE-2026-89942",
  "lastModified": "2026-09-16T15:18:19.573",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-16T11:17:03.860",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6288b593e76eb10329326f2cd51e32557203b9e5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6d4bdbf7bad63e759bf20259c527f69a1209e3dd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ab53077511cde811bf3ee219426c522329c41226"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f1f8f0e8e0af9cae8150658dc7bb51332f984893"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89942 (GCVE-0-2026-89942)

Vulnerability from cvelistv5 – Published: 2026-09-16 10:32 – Updated: 2026-09-16 14:40

Title

iio: buffer: Fix potential use-after-free in anonymous buffer release

Summary

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/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/ab53077511cde811b…
https://git.kernel.org/stable/c/f1f8f0e8e0af9cae8…
https://git.kernel.org/stable/c/6d4bdbf7bad63e759…
https://git.kernel.org/stable/c/6288b593e76eb1032…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f , < ab53077511cde811bf3ee219426c522329c41226 (git) Affected: 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f , < f1f8f0e8e0af9cae8150658dc7bb51332f984893 (git) Affected: 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f , < 6d4bdbf7bad63e759bf20259c527f69a1209e3dd (git) Affected: 3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f , < 6288b593e76eb10329326f2cd51e32557203b9e5 (git)
Linux	Linux	Affected: 6.11 Unaffected: 0 , < 6.11 (semver) Unaffected: 6.12.110 , ≤ 6.12.* (semver) Unaffected: 6.18.51 , ≤ 6.18.* (semver) Unaffected: 7.2.5 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iio/industrialio-buffer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ab53077511cde811bf3ee219426c522329c41226",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            },
            {
              "lessThan": "f1f8f0e8e0af9cae8150658dc7bb51332f984893",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            },
            {
              "lessThan": "6d4bdbf7bad63e759bf20259c527f69a1209e3dd",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            },
            {
              "lessThan": "6288b593e76eb10329326f2cd51e32557203b9e5",
              "status": "affected",
              "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iio/industrialio-buffer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.110",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.51",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.5",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: buffer: Fix potential use-after-free in anonymous buffer release\n\nAn anonymous buffer handle holds a reference to the underlying IIO device.\nThe reference is dropped in the buffer handle\u0027s release function. If the\ndevice has been removed, either through unbind or hot-unplug, the buffer\nhandle might hold the last reference.\n\nThe release function takes the mutex for the buffer using a guard, which\nmeans the unlock happens after all the code in the function, including\n`iio_device_put()`. If the anonymous buffer holds the last reference this\nmight free both the IIO device and the buffer, which contains the mutex,\nleading to use-after-free when the mutex is unlocked.\n\nFix this by using a scoped guard just around the buffer dmabuf list access,\nmaking sure the mutex is unlocked before releasing the IIO device.\n\nVersion 10 of the patch that introduced this issue used this exact scheme\nof first unlocking and then dropping the reference [1]. During review it\nwas suggested to use a guard instead, and version 11 made that change [2]."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The attacker reaches the bug by opening /dev/iio:deviceX, issuing IIO_BUFFER_GET_FD_IOCTL to get an anonymous IIO buffer fd, then closing that fd after the IIO device is gone. That is a local char-device ioctl/close path, not a network or USB descriptor parser.\nAC:L - This is a deterministic lifetime UAF, not a race: close() on the buffer fd unlocks buffer-\u003edmabufs_mutex after iio_device_put() has already freed it. The attacker controls open/ioctl/close and can drop the last device reference by hot-unplugging a USB IIO or HID-sensor device they opened.\nPR:L - iio_chrdev_open() and IIO_BUFFER_GET_FD_IOCTL perform no capability checks; access is only by /dev/iio:deviceX file mode. An unprivileged local user who can open that node (iio group, industrial DAQ, sensor HAL) can obtain the anonymous buffer fd.\nUI:N - The attacker opens the IIO device, obtains the buffer fd, removes the device, and closes the fd themselves. No separate victim action is required.\nS:U - The use-after-free is in kernel IIO buffer teardown and can escalate privileges only within the same kernel/OS authority. It does not cross a VM, IOMMU, or other security boundary.\nC:H - Closing the anonymous buffer fd use-after-frees the IIO buffer object that embeds dmabufs_mutex. A kernel heap UAF can be reclaimed to build an arbitrary read primitive.\nI:H - The cleanup guard unlocks dmabufs_mutex after iio_dev_release() has already destroyed that mutex and freed the buffer, writing into freed kernel memory. That UAF is exploitable for heap corruption and control-flow hijack.\nA:H - Use-after-free of the buffer mutex during anonymous-buffer release can oops or panic the kernel even without a fully controlled exploit, causing complete availability loss."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T14:40:29.770Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ab53077511cde811bf3ee219426c522329c41226"
        },
        {
          "url": "https://git.kernel.org/stable/c/f1f8f0e8e0af9cae8150658dc7bb51332f984893"
        },
        {
          "url": "https://git.kernel.org/stable/c/6d4bdbf7bad63e759bf20259c527f69a1209e3dd"
        },
        {
          "url": "https://git.kernel.org/stable/c/6288b593e76eb10329326f2cd51e32557203b9e5"
        }
      ],
      "title": "iio: buffer: Fix potential use-after-free in anonymous buffer release",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89942",
    "datePublished": "2026-09-16T10:32:29.836Z",
    "dateReserved": "2026-09-11T19:38:34.777Z",
    "dateUpdated": "2026-09-16T14:40:29.770Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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