CVE Catalog

CVE-2026-64327

Low risk· EPSS 10%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.20%

10th percentile - higher than 10% of all known CVEs

Summary

In the Linux kernel's USB gadget f_fs driver, the epfile->in field is initialized too late, causing incorrect DMA direction for early ioctl calls.

Risk Assessment

This can lead to incorrect DMA operation and potential data corruption or memory integrity issues.

Recommendation

Apply the Linux kernel patch that moves epfile->in initialization to ffs_epfiles_create().

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS