CVE-2025-71192

The vulnerability is a double free in snd_ac97_controller_register() in the ALSA AC97 driver. When ac97_add_adapter() fails, the code incorrectly used kfree() instead of put_device(), causing a double free. Additionally, missing kfree() calls when idr_alloc() fails and in ac97_adapter_release() could lead to memory leaks.

Exploitation requires the ability to trigger the error path during AC97 controller registration, which typically involves specific hardware or driver conditions. The vulnerability is reachable locally but prerequisites are limited.

A successful exploit could cause double free memory corruption, potentially leading to system crash or privilege escalation in a kernel context.

The issue was fixed by commits [1] and [2] in the Linux kernel stable trees. Users are advised to apply the latest security updates.