Thanks for pointing this out. What an unusual error.
Tom, any ideas on this? I didn't see anything in the logs I checked that seemed to be related to this (as an aside, there seems to be some chron job that is seg faulting every minute or so). It doesn't seem to be an issue with MediaWiki. Has anything changed related to server configuration semi-recently (I guess it could have happened a while ago, since I haven't uploaded an image for a long time).
It's not every special page, but it's not just Special:Upload, either. I also noticed that Special:SpecialPages gets the same error, which is rather unusual, since there isn't really anything that interesting going on on those pages (compared to the regular pages).