There are several comic book viewers on Linux for cbr, cbz, RAR, and ZIP files. The most popular of these would be Comix. This is the one I tend to use. There are others that you may find better to your liking. I've compiled a list of digital comic book viewers below.
Here is a list of comic book viewers on Linux:
(This is all I could find. If you know of any others please tell me so I may add them to the list. Thanks)