Findings

CVE-2025-40315

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix epfile null pointer access after ep enable.

Published Dec 8, 2025 · updated Oct 14, 2026

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

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 8, 2025 · NIST NVD

    Detected

    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->

  2. Oct 14, 2026 · NIST NVD

    Updated

    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->

Sources

  • CVE.orgVulnerability recordCVE-2025-40315

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-40315

    30-day exploitation probability 0.2%

    first.org
  • NIST NVDVulnerability recordCVE-2025-40315

    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() set

    nvd.nist.gov

References

CVE-2025-40315 · ZeroDay Findings