What is the ruling on self-immolation as a protest against injustice?

Suicide is one of the gravest sins that necessitates eternal damnation, based on Allah's saying: "And do not throw yourselves with your own hands into destruction," and "And do not kill yourselves. Indeed, Allah is ever Merciful to you." It was also narrated from Abu Hurairah that the Prophet, peace and blessings be upon him, said: "Whoever throws himself down from a mountain and kills himself will be in the Fire of Hell, throwing himself down in it eternally. And whoever drinks poison and kills himself will have his poison in his hand, drinking it in the Fire of Hell eternally. And whoever kills himself with a piece of iron will have his iron in his hand, thrusting it into his belly in the Fire of Hell eternally." It was narrated from Jundub bin Abdullah that the Prophet, peace and blessings be upon him, said: "My servant hastened against Me with his soul, so I have forbidden Paradise for him."

It is not permissible for a servant to end his life by his own hand for any reason. Whoever wishes to protest against injustice must do so through legitimate means to confront injustice and punish the oppressors, in accordance with what Allah has legislated, not what He has forbidden.