CVE-2025-39861: Bluetooth: vhci: Prevent use-after-free by removing debugfs files early

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-19 · updated 2026-10-19
Weakness: CWE-416

Description

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.

Affected products

Linux kernel: from 6.4 before 6.6.105; from 6.7 before 6.12.46; from 6.13 before 6.16.6; 6.17-rc1, 6.17-rc2, 6.17-rc3, 6.17-rc4 — fixed in 6.12.46, 6.16.6, 6.6.105

How to fix

Upgrade to a fixed version: Linux kernel 6.12.46, 6.16.6, 6.6.105. Check the vendor advisory for mitigations.

References

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