services/audioflinger/Effects.cpp in mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-08-01 does not validate the reply size for an AudioFlinger effect command, which allows attackers to gain privileges via a crafted application, aka internal bug 29251553.