GHSA-HCJ7-CP6W-GVX9

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



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