Probably one of the easiest malfunctions to deal with because you can see it.

This type of malfunction is also called a "failure to eject," and it is often caused by "limp wristing" the gun. In this case, the expended cartidge is not fully ejected and ends up stuck in the ejection port. Hence, the name, stovepipe, because it is typically sticking straight up in the port.

Clearing this malfunction is very easy. After identifying what has happened, make a "blade" with your non-shooting hand, place it on top of the slide without passing over the muzzle, place the edge of your index finger (with all of your other fingers forming a "blade" on your off hand) against the stove-piped cartridge, and sweep back against the cartridge, all the way past the shoulder of you gun hand. The cartridge will eject, the gun will go into battery, and you will be prepared to shoot your next round.