CVE-2025-40315

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_fs: Fix epfile null pointer access after ep enable.

A race condition occurs when ffs_func_eps_enable() runs concurrently

with ffs_data_reset(). The ffs_data_clear() called in ffs_data_reset()

sets ffs->epfiles to NULL before resetting ffs->eps_count to 0, leading

to a NULL pointer dereference when accessing epfile->ep in

ffs_func_eps_enable() after successful usb_ep_enable().

The ffs->epfiles pointer is set to NULL in both ffs_data_clear() and

ffs_data_close() functions, and its modification is protected by the

spinlock ffs->eps_lock. And the whole ffs_func_eps_enable() function

is also protected by ffs->eps_lock.

Thus, add NULL pointer handling for ffs->epfiles in the

ffs_func_eps_enable() function to fix issues

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References