Linux Kernel up to 6.12.95/6.18.38/7.1.3/7.2-rc2 f_fs f_fs.c ffs_dmabuf_transfer double free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.8$0-$5k3.11-

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.12.95/6.18.38/7.1.3/7.2-rc2. This vulnerability affects the function ffs_dmabuf_transfer of the file f_fs.c of the component f_fs. Executing a manipulation can lead to double free. This vulnerability is tracked as CVE-2026-64328. The attack is restricted to local execution. No exploit exists.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.12.95/6.18.38/7.1.3/7.2-rc2. This vulnerability affects the function ffs_dmabuf_transfer of the file f_fs.c of the component f_fs. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-64328 since 07/19/2026. The exploitation appears to be easy. Local access is required to approach this attack. Additional levels of successful authentication are required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/25/2026).

Upgrading to version 6.12.96, 6.18.39, 7.1.4 or 7.2-rc3 eliminates this vulnerability. Applying the patch b7475b2dce5e121e687280ba5732ccefe77ffd2f/e086c16962a1b0142e2675610e9c06fcfcd4c3a8/0cae3d6109427c455bad0a18dfb3e2a91657e38a/baa6b6068a3f2bf2ed525a1cb37975905dadc658 is able to eliminate this problem.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.96/6.18.39/7.1.4/7.2-rc3
Patch: b7475b2dce5e121e687280ba5732ccefe77ffd2f/e086c16962a1b0142e2675610e9c06fcfcd4c3a8/0cae3d6109427c455bad0a18dfb3e2a91657e38a/baa6b6068a3f2bf2ed525a1cb37975905dadc658

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64328 (🔒)
GCVE (CVE): GCVE-0-2026-64328
GCVE (VulDB): GCVE-100-383122

Entryinfo

Created: 07/25/2026 15:33
Changes: 07/25/2026 15:33 (60)
Complete: 🔍
Cache ID: 216::103

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