High CPU on 8 byte file (CIN) - f4d87e8b

[JodieC]

Hi IM Team,

This one is a little different, and I had a fun time pinning down where this is coming from.

I was testing this file against the IM6 from SVN 20141227 and found that this 8 byte file, or ones like it, would use up 15-30 seconds of CPU time.
https://www.dropbox.com/s/z1e0z3k41ewjmw1/f4d87e8b?dl=0

Running valgrind seems to point to blob.c and show that it's spending most of its time in ReadBlobByte.
22 seconds was in ReadCINImage and 17 of that was in ReadBlobByte.


System Details:
AMD64
Distributor ID: Ubuntu
Description: Ubuntu 14.04.1 LTS
Release: 14.04
Codename: trusty

Found with American Fuzzy Lop ( http://lcamtuf.coredump.cx/afl/ )

[magick]

We can reproduce the problem you posted and have a patch in ImageMagick 6.9.0-3 Beta, available by sometime tomorrow. Thanks.