CVE-2026-64327

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux7b07a2a7ca02a20124b552be96c5a56910795488 < 82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716baffected
LinuxLinux7b07a2a7ca02a20124b552be96c5a56910795488 < 9e04055ab5fc0470a0031ee6934739f9aa8f34a5affected
LinuxLinux7b07a2a7ca02a20124b552be96c5a56910795488 < f99f32ea9aa976afcbec20647ed33b50a52002c1affected
LinuxLinux7b07a2a7ca02a20124b552be96c5a56910795488 < 82cfd4739011bdc7e87b5d585703427e89ddfaa5affected
LinuxLinux6.9affected
LinuxLinux0 < 6.9unaffected
LinuxLinux6.12.96 <= 6.12.*unaffected
LinuxLinux6.18.39 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc3 <= *unaffected

Weaknesses

References