Vulnerability-Lookup

GHSA-HCJ7-CP6W-GVX9

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32

Details

In the Linux kernel, the following vulnerability has been resolved:

rapidio: mport_cdev: fix use-after-free in dma_req_free()

dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex.

If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free.

Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking.

The bug is reachable from userspace via the RapidIO mport character device interface.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89742"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:20:04Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrapidio: mport_cdev: fix use-after-free in dma_req_free()\n\ndma_req_free() acquires buf_mutex through req-\u003emap, drops the mapping\nreference with kref_put(), and then dereferences req-\u003emap again to unlock\nthe mutex.\n\nIf kref_put() drops the last reference, mport_release_mapping() frees the\nmapping, and the subsequent mutex_unlock() dereferences a freed object. \nThis is a use-after-free.\n\nFix this by caching map and md before kref_put(), clearing req-\u003emap while\nholding buf_mutex, and using the cached md for mutex unlocking.\n\nThe bug is reachable from userspace via the RapidIO mport character device\ninterface.",
  "id": "GHSA-hcj7-cp6w-gvx9",
  "modified": "2026-09-14T15:32:36Z",
  "published": "2026-09-11T21:31:38Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89742"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/00c5ed913b0dc563fbeb8a97ea8916c03bbbbf6a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/211c68d817a3d9dc14c0026a59da7cac30f8147e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/26ccfe7d69e27b0d933ae0a64a23a0cb9b9a85a6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5cbef379a94b161726c5f504598bf4791d45cedc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9a9929ec875ff20922c90c96fd544ae8a2a61a8d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bd8881c24a9520f9c3d3e855d866197f63e471a7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc79c07cdcde02c5b17633d78777de6ac2c14b29"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89742 (GCVE-0-2026-89742)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:46 – Updated: 2026-09-14 12:02

Title

rapidio: mport_cdev: fix use-after-free in dma_req_free()

Summary

In the Linux kernel, the following vulnerability has been resolved: rapidio: mport_cdev: fix use-after-free in dma_req_free() dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free. Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking. The bug is reachable from userspace via the RapidIO mport character device interface.

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

8 references

URL	Tags
https://git.kernel.org/stable/c/00c5ed913b0dc563f…
https://git.kernel.org/stable/c/fc79c07cdcde02c5b…
https://git.kernel.org/stable/c/26ccfe7d69e27b0d9…
https://git.kernel.org/stable/c/bd8881c24a9520f9c…
https://git.kernel.org/stable/c/9a9929ec875ff2092…
https://git.kernel.org/stable/c/e6e925cc1f8067c65…
https://git.kernel.org/stable/c/211c68d817a3d9dc1…
https://git.kernel.org/stable/c/5cbef379a94b16172…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < 00c5ed913b0dc563fbeb8a97ea8916c03bbbbf6a (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < fc79c07cdcde02c5b17633d78777de6ac2c14b29 (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < 26ccfe7d69e27b0d933ae0a64a23a0cb9b9a85a6 (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < bd8881c24a9520f9c3d3e855d866197f63e471a7 (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < 9a9929ec875ff20922c90c96fd544ae8a2a61a8d (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0 (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < 211c68d817a3d9dc14c0026a59da7cac30f8147e (git) Affected: e8de370188d098bb49483c287b44925957c3c9b6 , < 5cbef379a94b161726c5f504598bf4791d45cedc (git)
Linux	Linux	Affected: 4.6 Unaffected: 0 , < 4.6 (semver) Unaffected: 5.10.270 , ≤ 5.10.* (semver) Unaffected: 5.15.221 , ≤ 5.15.* (semver) Unaffected: 6.1.188 , ≤ 6.1.* (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.109 , ≤ 6.12.* (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/rapidio/devices/rio_mport_cdev.c"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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          "versions": [
            {
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              "versionType": "git"
            },
            {
              "lessThan": "fc79c07cdcde02c5b17633d78777de6ac2c14b29",
              "status": "affected",
              "version": "e8de370188d098bb49483c287b44925957c3c9b6",
              "versionType": "git"
            },
            {
              "lessThan": "26ccfe7d69e27b0d933ae0a64a23a0cb9b9a85a6",
              "status": "affected",
              "version": "e8de370188d098bb49483c287b44925957c3c9b6",
              "versionType": "git"
            },
            {
              "lessThan": "bd8881c24a9520f9c3d3e855d866197f63e471a7",
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              "versionType": "git"
            },
            {
              "lessThan": "9a9929ec875ff20922c90c96fd544ae8a2a61a8d",
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              "versionType": "git"
            },
            {
              "lessThan": "e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0",
              "status": "affected",
              "version": "e8de370188d098bb49483c287b44925957c3c9b6",
              "versionType": "git"
            },
            {
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              "versionType": "git"
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "4.6"
            },
            {
              "lessThan": "4.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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                  "versionEndExcluding": "5.10.270",
                  "versionStartIncluding": "4.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.221",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "4.6",
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
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                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
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                  "versionStartIncluding": "4.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "4.6",
                  "vulnerable": true
                }
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              "negate": false,
              "operator": "OR"
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        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrapidio: mport_cdev: fix use-after-free in dma_req_free()\n\ndma_req_free() acquires buf_mutex through req-\u003emap, drops the mapping\nreference with kref_put(), and then dereferences req-\u003emap again to unlock\nthe mutex.\n\nIf kref_put() drops the last reference, mport_release_mapping() frees the\nmapping, and the subsequent mutex_unlock() dereferences a freed object. \nThis is a use-after-free.\n\nFix this by caching map and md before kref_put(), clearing req-\u003emap while\nholding buf_mutex, and using the cached md for mutex unlocking.\n\nThe bug is reachable from userspace via the RapidIO mport character device\ninterface."
        }
      ],
      "metrics": [
        {
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            "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"
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          "scenarios": [
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              "lang": "en",
              "value": "AV:L - The use-after-free is reached only through local ioctls on /dev/rio_mportN (RIO_ALLOC_DMA, RIO_TRANSFER with a kernel DMA handle, RIO_FREE_DMA, then close or RIO_WAIT_FOR_ASYNC). RapidIO is a board-level fabric, and this dma_req_free() path is not driven by received packets.\nAC:L - An attacker who can open the mport node deterministically allocates a DMA mapping, submits an async RIO_TRANSFER that takes a kref on it, drops the owner ref with RIO_FREE_DMA, then frees the request so dma_req_free() performs the last kref_put(); no condition outside the attacker\u2019s control is required.\nPR:L - mport_cdev_open() and the DMA ioctls perform no capable() checks; access is gated only by /dev/rio_mportN permissions, and RapidIO deployments commonly give fabric-management daemons group access to that node, so an unprivileged local user with the device can drive the bug.\nUI:N - Exploitation is entirely self-driven via the attacker\u2019s own open/ioctl/close sequence on the mport character device; no separate victim action such as mounting a filesystem or opening a file is required.\nS:U - The freed rio_mport_mapping and the subsequent mutex unlock occur in kernel heap within the host OS authority; this is a standard kernel use-after-free and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - dma_req_free() dereferences req-\u003emap after mport_release_mapping() has kfree\u2019d that kmalloc object; reclaiming the slab lets an attacker control map-\u003emd and read through the dangling pointer, a classic use-after-free disclosure primitive.\nI:H - Unlocking buf_mutex via a reclaimed map-\u003emd causes mutex_unlock() on an attacker-chosen address (fake-mutex wait_list write), so the use-after-free is exploitable for arbitrary kernel write and control-flow hijack.\nA:H - Use-after-free of rio_mport_mapping during mutex_unlock() oopses or panics under slab poisoning or init_on_free, and targeting a fake md leaves the real buf_mutex locked, deadlocking mapping paths and crashing or hanging the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-14T12:02:25.695Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/00c5ed913b0dc563fbeb8a97ea8916c03bbbbf6a"
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          "url": "https://git.kernel.org/stable/c/bd8881c24a9520f9c3d3e855d866197f63e471a7"
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        },
        {
          "url": "https://git.kernel.org/stable/c/211c68d817a3d9dc14c0026a59da7cac30f8147e"
        },
        {
          "url": "https://git.kernel.org/stable/c/5cbef379a94b161726c5f504598bf4791d45cedc"
        }
      ],
      "title": "rapidio: mport_cdev: fix use-after-free in dma_req_free()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89742",
    "datePublished": "2026-09-11T19:46:48.522Z",
    "dateReserved": "2026-09-11T19:38:34.761Z",
    "dateUpdated": "2026-09-14T12:02:25.695Z",
    "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

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.