CVE-2026-64327EPSS p4.4%
CVE-2026-64327CVE-2026-64327
linux / linux_kernel
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.
Scoring
| CVSS | 5.5 () |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| EPSS | 0.16% probability of exploitation · percentile 4.4% · 2026-10-05T12:00:23Z |
| Last modified | 2026-09-04 |