There's a freeze tag, which I think I created, meaning cases when something is not responding. I think that's a useful tag because people use lots of different words to express this situation, so it's otherwise hard to search for.
(Note: I think it's not a meta-tag, because it has a valid, objective meaning. However, I can't see it be used alone — there should be an application or OS tag alongside.)
There's no similar general tag for crashes; do we not need one, or have we not recognized the need for one? Maybe it's enough to just have kernel-panic and segmentation-fault. (Side note: please make a synonym segfault → segmentation-fault.)