CVE-2026-64327

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.

Score

CVSS 3.1 5.5 Medium

Status

Analyzed - 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-07-25

Last modified

2026-08-17

Affected products

• Linux Kernel (Linux)

References

• https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b
• https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5
• https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5
• https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1