Malaysia is a pretty large exception and most people who convert away from Islam are not allowed to
Conversion from Islam
Muslims who wish to convert from Islam face severe obstacles. For Muslims, particularly ethnic Malays, the right to leave the Islamic faith and adhere to another religion is a controversial question. The legal process of conversion is also unclear; in practice it is very difficult for Muslims to change their religion legally.
In 1999 the High Court ruled that secular courts have no jurisdiction to hear applications by Muslims to change religions. According to the ruling, the religious conversion of Muslims lies solely within the jurisdiction of Islamic courts.
The issue of Muslim apostasy is very sensitive. In 1998 after a controversial incident of attempted conversion, the Government stated that apostates (i.e., Muslims who wish to leave or have left Islam for another religion) would not face government punishment so long as they did not defame Islam after their conversion. However, whether the very act of conversion was an "insult to Islam" was not clarified at the time. The Government opposes what it considers deviant interpretations of Islam, maintaining that the "deviant" groups' extreme views endanger national security. In 2005 international media attention focused on the Sky Kingdom sect whose founder Ayah Pin claimed to be God, and whose members – mostly Malays – were accordingly charged with religious "deviancy" and "humiliating Islam."
article has a lot of other details about the relative lack of religious mobility and intolerance towards non Muslims -particularly Hindus
-I'm just sayin'