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CVE-2026-64328 (GCVE-0-2026-64328)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-08-17 04:53
VLAI
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.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 7b07a2a7ca02a20124b552be96c5a56910795488 , < b7475b2dce5e121e687280ba5732ccefe77ffd2f (git)
Affected: 7b07a2a7ca02a20124b552be96c5a56910795488 , < e086c16962a1b0142e2675610e9c06fcfcd4c3a8 (git)
Affected: 7b07a2a7ca02a20124b552be96c5a56910795488 , < 0cae3d6109427c455bad0a18dfb3e2a91657e38a (git)
Affected: 7b07a2a7ca02a20124b552be96c5a56910795488 , < baa6b6068a3f2bf2ed525a1cb37975905dadc658 (git)
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Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.12.96 , ≤ 6.12.* (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
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    "dateReserved": "2026-07-19T15:36:31.780Z",
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
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      "cve": "CVE-2026-64328",
      "id": "CVE-2026-64328",
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      "title": "kernel: usb: gadget: f_fs: Fix DMA fence leak",
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      "current_release_date": "2026-09-05T00:30:10Z",
      "cve": "CVE-2026-64328",
      "id": "CVE-2026-64328",
      "initial_release_date": "2026-07-25T16:45:36Z",
      "product_status:known_not_affected": "376",
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      "title": "SUSE CVE CVE-2026-64328",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64328.json",
      "version": "6"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


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.