usb: gadget: f_fs: Fix DMA fence leak

{
  "id": "0384c5001a694219a043c19fa45014c695b277188f991d757b8fdc9b7b775aea",
  "url": "https://osv.dev/vulnerability/CVE-2026-64328",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "usb: gadget: f_fs: Fix DMA fence leak",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix DMA fence leak In ffs_dmabuf_transfer(), a ffs_dma_fence object is kmalloc'd, with the underlying dma_fence later initialized by dma_fence_init(), which sets its kref counter to 1. Then, dma_resv_add_fence() gets a second reference, and a pointer to the ffs_dma_fence is passed as the usb_request's \"context\" field. The dma-resv mechanism will manage the second reference, but the first reference is never properly released; the ffs_dmabuf_cleanup() function decreases the reference count, but only to balance with the reference grab in ffs_dmabuf_signal_done(). The code will then slowly leak memory as more ffs_dma_fence objects are created without being ever freed. Address this issue by transferring ownership of the fence to the DMA reservation object, by calling dma_fence_put() right after dma_resv_add_fence(). The ffs_dma_fence then gets properly discarded after being signalled.",
    "evidence": "osv:CVE-2026-64328",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.96",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.39",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-64328",
      "aliases": [
        "CVE-2026-64328"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "7b07a2a7ca02a20124b552be96c5a56910795488"
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                {
                  "fixed": "b7475b2dce5e121e687280ba5732ccefe77ffd2f"
                },
                {
                  "fixed": "e086c16962a1b0142e2675610e9c06fcfcd4c3a8"
                },
                {
                  "fixed": "0cae3d6109427c455bad0a18dfb3e2a91657e38a"
                },
                {
                  "fixed": "baa6b6068a3f2bf2ed525a1cb37975905dadc658"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64328.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.9.0"
                },
                {
                  "fixed": "6.12.96"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.39"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64328.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.545653265Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0cae3d6109427c455bad0a18dfb3e2a91657e38a",
        "https://git.kernel.org/stable/c/b7475b2dce5e121e687280ba5732ccefe77ffd2f",
        "https://git.kernel.org/stable/c/baa6b6068a3f2bf2ed525a1cb37975905dadc658",
        "https://git.kernel.org/stable/c/e086c16962a1b0142e2675610e9c06fcfcd4c3a8",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64328.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64328",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64328.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64328",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 513533,
  "published_at": "2026-07-25T08:49:56.34+00:00"
}