CVE-2025-39861

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

Bluetooth: vhci: Prevent use-after-free by removing debugfs files early

Move the creation of debugfs files into a dedicated function, and ensure they are explicitly removed during vhci_release(), before associated data structures are freed.

Previously, debugfs files such as "force_suspend", "force_wakeup", and others were created under hdev->debugfs but not removed in vhci_release(). Since vhci_release() frees the backing vhci_data structure, any access to these files after release would result in use-after-free errors.

Although hdev->debugfs is later freed in hci_release_dev(), user can access files after vhci_data is freed but before hdev->debugfs is released.

The bug is a use-after-free in the Bluetooth vhci driver: debugfs files could remain accessible after vhci_release() freed the backing vhci_data, leading to UAF on file access. Exploitation requires local, highly-privileged access (to /dev/vhci and debugfs), so the realistic impact is a local kernel DoS only.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.