Fireball and SmallFireball entities crash the game when created with the /summon command. Sometimes the game simply freezes, sometimes it instantly closes itself and returns to the launcher. It happens in the tick right after hitting enter or triggering the redstone circuit with command block.

Fireballs created by Ghasts, Blazes and Dispensers do not create any issues, though.
Other entities, even other projectiles such as arrows and thrown potions can be summoned without problems.

It might be related to the Linux implementation of Java, since the issue never occured on Windows systems.
The selected Minecraft version is a potentially unstable snapshot, but I experienced the problem in past full releases as well.

To reproduce:
1. Install Minecraft on a Linux system (perhaps 64 bit only, had no chance to test on 32 bit)
2. Create a world with cheats enabled
3. /summon Fireball ~ ~ ~
4. Crash