Linux Kernel ALSA Timer Mutex Deadlock Vulnerability

A vulnerability in the Linux kernel's ALSA timer code could lead to deadlocks due to improper mutex handling. The issue arises from the 'register_mutex' being held during 'copy_from/to_user()' operations, a pattern that was inadvertently introduced and had previously been carefully managed. This vulnerability has been addressed by relocating the 'copy_from/to_user()' calls out of the 'register_mutex' lock.

Impact

The vulnerability could cause deadlocks, disrupting normal operation by causing processes to hang indefinitely while waiting for resources to become available.