CVE-2026-64328

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/0cae3d6109427c455bad0a18dfb3e2a91657e38a	Patch
https://git.kernel.org/stable/c/b7475b2dce5e121e687280ba5732ccefe77ffd2f	Patch
https://git.kernel.org/stable/c/baa6b6068a3f2bf2ed525a1cb37975905dadc658	Patch
https://git.kernel.org/stable/c/e086c16962a1b0142e2675610e9c06fcfcd4c3a8	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:7.2:rc1::::::
	cpe:2.3:o:linux:linux_kernel:7.2:rc2::::::

History

No history.

Information

Published : 2026-07-25 10:17

Updated : 2026-09-04 14:50

NVD link : CVE-2026-64328

Mitre link : CVE-2026-64328

CVE.ORG link : CVE-2026-64328

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-401

Missing Release of Memory after Effective Lifetime

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Then, dma_resv_add_fence() gets a second\nreference, and a pointer to the ffs_dma_fence is passed as the\nusb_request's \"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."}], "lastModified": "2026-09-04T14:50:44.503", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "95CEF1E2-98DB-4D14-8BB5-1BF3FA9BF03C", "versionEndExcluding": "6.12.96", "versionStartIncluding": "6.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7", "versionEndExcluding": "6.18.39", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42", "versionEndExcluding": "7.1.4", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5E8B9085-7ADB-4A05-89EF-12949B6A0509"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1FC0D50D-9D58-4947-A197-A5A3FF07E7E3"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}