In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks When parsing endpoint descriptors, ffs_data_got_descs() generates the eps_addrmap which contains the endpoint direction. However, epfile->in was previously only populated in ffs_func_eps_enable() which executes upon USB host connection. As a result, early userspace ioctls like FUNCTIONFS_DMABUF_ATTACH that run before the host connects would see epfile->in as 0, leading to incorrect DMA directions. By moving the initialization to ffs_epfiles_create(), epfile->in is accurate before userspace opens the endpoint files.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b cve-icon
https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5 cve-icon
https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5 cve-icon
https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1 cve-icon
https://lore.kernel.org/linux-cve-announce/2026072512-CVE-2026-64327-fb4d@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-64327 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-64327 cve-icon
History

Thu, 30 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-908
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Thu, 30 Jul 2026 04:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-754

Mon, 27 Jul 2026 06:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-754

Sat, 25 Jul 2026 09:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks When parsing endpoint descriptors, ffs_data_got_descs() generates the eps_addrmap which contains the endpoint direction. However, epfile->in was previously only populated in ffs_func_eps_enable() which executes upon USB host connection. As a result, early userspace ioctls like FUNCTIONFS_DMABUF_ATTACH that run before the host connects would see epfile->in as 0, leading to incorrect DMA directions. By moving the initialization to ffs_epfiles_create(), epfile->in is accurate before userspace opens the endpoint files.
Title usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-07-25T08:49:55.426Z

Updated: 2026-07-25T08:49:55.426Z

Reserved: 2026-07-19T15:36:31.780Z

Link: CVE-2026-64327

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-25T00:00:00Z

Links: CVE-2026-64327 - Bugzilla