FKIE_CVE-2026-64328
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: 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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"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": "b7475b2dce5e121e687280ba5732ccefe77ffd2f",
"status": "affected",
"version": "7b07a2a7ca02a20124b552be96c5a56910795488",
"versionType": "git"
},
{
"lessThan": "e086c16962a1b0142e2675610e9c06fcfcd4c3a8",
"status": "affected",
"version": "7b07a2a7ca02a20124b552be96c5a56910795488",
"versionType": "git"
},
{
"lessThan": "0cae3d6109427c455bad0a18dfb3e2a91657e38a",
"status": "affected",
"version": "7b07a2a7ca02a20124b552be96c5a56910795488",
"versionType": "git"
},
{
"lessThan": "baa6b6068a3f2bf2ed525a1cb37975905dadc658",
"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: Fix DMA fence leak\n\nIn ffs_dmabuf_transfer(), a ffs_dma_fence object is kmalloc\u0027d, with the\nunderlying dma_fence later initialized by dma_fence_init(), which sets\nits kref counter to 1. Then, dma_resv_add_fence() gets a second\nreference, and a pointer to the ffs_dma_fence is passed as the\nusb_request\u0027s \"context\" field.\n\nThe dma-resv mechanism will manage the second reference, but the first\nreference is never properly released; the ffs_dmabuf_cleanup() function\ndecreases the reference count, but only to balance with the reference\ngrab in ffs_dmabuf_signal_done().\n\nThe code will then slowly leak memory as more ffs_dma_fence objects are\ncreated without being ever freed.\n\nAddress this issue by transferring ownership of the fence to the DMA\nreservation object, by calling dma_fence_put() right after\ndma_resv_add_fence(). The ffs_dma_fence then gets properly discarded\nafter being signalled."
}
],
"id": "CVE-2026-64328",
"lastModified": "2026-07-25T10:17:14.430",
"metrics": {},
"published": "2026-07-25T10:17:14.430",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0cae3d6109427c455bad0a18dfb3e2a91657e38a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b7475b2dce5e121e687280ba5732ccefe77ffd2f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/baa6b6068a3f2bf2ed525a1cb37975905dadc658"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e086c16962a1b0142e2675610e9c06fcfcd4c3a8"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
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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.
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