CVE-2021-47281

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to a race condition in the snd seq timer open() function, where the timer instance per queue is exclusive, but concurrent accesses are not properly managed. This can lead to a situation where a later concurrent call of snd seq timer open() may override the timer instance, resulting in a Use After Free (UAF) condition. The UAF can occur when the leftover timer instance continues to run after the queue itself has been closed. To avoid the race, a proper check is added at the assignment of tmr->timeri to return -EBUSY if it has already been registered.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.