FKIE_CVE-2026-64327

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-25 10:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks When parsing endpoint descriptors, ffs_data_got_descs() generates the eps_addrmap which contains the endpoint direction. However, epfile->in was previously only populated in ffs_func_eps_enable() which executes upon USB host connection. As a result, early userspace ioctls like FUNCTIONFS_DMABUF_ATTACH that run before the host connects would see epfile->in as 0, leading to incorrect DMA directions. By moving the initialization to ffs_epfiles_create(), epfile->in is accurate before userspace opens the endpoint files.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b",
              "status": "affected",
              "version": "7b07a2a7ca02a20124b552be96c5a56910795488",
              "versionType": "git"
            },
            {
              "lessThan": "9e04055ab5fc0470a0031ee6934739f9aa8f34a5",
              "status": "affected",
              "version": "7b07a2a7ca02a20124b552be96c5a56910795488",
              "versionType": "git"
            },
            {
              "lessThan": "f99f32ea9aa976afcbec20647ed33b50a52002c1",
              "status": "affected",
              "version": "7b07a2a7ca02a20124b552be96c5a56910795488",
              "versionType": "git"
            },
            {
              "lessThan": "82cfd4739011bdc7e87b5d585703427e89ddfaa5",
              "status": "affected",
              "version": "7b07a2a7ca02a20124b552be96c5a56910795488",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-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\nusb: gadget: f_fs: Initialize epfile-\u003ein early to fix endpoint direction checks\n\nWhen parsing endpoint descriptors, ffs_data_got_descs() generates the\neps_addrmap which contains the endpoint direction. However, epfile-\u003ein\nwas previously only populated in ffs_func_eps_enable() which executes\nupon USB host connection. As a result, early userspace ioctls like\nFUNCTIONFS_DMABUF_ATTACH that run before the host connects would see\nepfile-\u003ein as 0, leading to incorrect DMA directions.\n\nBy moving the initialization to ffs_epfiles_create(), epfile-\u003ein is\naccurate before userspace opens the endpoint files."
    }
  ],
  "id": "CVE-2026-64327",
  "lastModified": "2026-07-25T10:17:14.327",
  "metrics": {},
  "published": "2026-07-25T10:17:14.327",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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