usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks (CVE-2026-64327) | HOL Guard CVE

Medium · CVSS 5.5CVE-2026-64327

usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks

Answer in brief

CVE-2026-64327 records a Medium severity (CVSS 5.5) vulnerability in usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 25, 2026Updated Sep 4, 2026Source checked Oct 1, 2026First seen by HOL Aug 11, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.5
Exploitation: Not marked as known exploited
Affected software: 5 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.2:rc1::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.2:rc2::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=7b07a2a7ca02a20124b552be96c5a56910795488 <82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b \|\| >=7b07a2a7ca02a20124b552be96c5a56910795488 <9e04055ab5fc0470a0031ee6934739f9aa8f34a5 \|\| >=7b07a2a7ca02a20124b552be96c5a56910795488 <f99f32ea9aa976afcbec20647ed33b50a52002c1 \|\| >=7b07a2a7ca02a20124b552be96c5a56910795488 <82cfd4739011bdc7e87b5d585703427e89ddfaa5	82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b, 9e04055ab5fc0470a0031ee6934739f9aa8f34a5, f99f32ea9aa976afcbec20647ed33b50a52002c1, 82cfd4739011bdc7e87b5d585703427e89ddfaa5
Linux/Linuxgeneric	6.9	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.