CVE-2026-64328
usb: gadget: f_fs: Fix DMA fence leak
Description
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.
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Transfer fence ownership to the DMA reservation object.
- Call dma_fence_put() after dma_resv_add_fence().
- Ensure ffs_dma_fence is properly discarded after signaling.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64328.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64328 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64328
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64328 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64328 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'b7475b2dce5e121e687280ba5732ccefe77ffd2f', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'e086c16962a1b0142e2675610e9c06fcfcd4c3a8', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': '0cae3d6109427c455bad0a18dfb3e2a91657e38a', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'baa6b6068a3f2bf2ed525a1cb37975905dadc658', 'versionType': 'git'}], 'programFiles': ['drivers/usb/gadget/function/f_fs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.9'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.9', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc3', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/usb/gadget/function/f_fs.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'b7475b2dce5e121e687280ba5732ccefe77ffd2f', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'e086c16962a1b0142e2675610e9c06fcfcd4c3a8', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': '0cae3d6109427c455bad0a18dfb3e2a91657e38a', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'baa6b6068a3f2bf2ed525a1cb37975905dadc658', 'versionType': 'git'}], 'programFiles': ['drivers/usb/gadget/function/f_fs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.9'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.9', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/usb/gadget/function/f_fs.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'b7475b2dce5e121e687280ba5732ccefe77ffd2f', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'e086c16962a1b0142e2675610e9c06fcfcd4c3a8', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': '0cae3d6109427c455bad0a18dfb3e2a91657e38a', 'versionType': 'git'}, {'status': 'affected', 'version': '7b07a2a7ca02a20124b552be96c5a56910795488', 'lessThan': 'baa6b6068a3f2bf2ed525a1cb37975905dadc658', 'versionType': 'git'}], 'programFiles': ['drivers/usb/gadget/function/f_fs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.9'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.9', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc3', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/usb/gadget/function/f_fs.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/0cae3d6109427c455bad0a18dfb3e2a91657e38a Added Reference https://git.kernel.org/stable/c/b7475b2dce5e121e687280ba5732ccefe77ffd2f Added Reference https://git.kernel.org/stable/c/baa6b6068a3f2bf2ed525a1cb37975905dadc658 Added Reference https://git.kernel.org/stable/c/e086c16962a1b0142e2675610e9c06fcfcd4c3a8