On 04/16/2014 05:13 AM, Norihiro Tanaka wrote:
> http://bugs.exim.org/show_bug.cgi?id=1468 

Thanks.  The response there makes it clear that if grep passes arbitrary 
binary data to PCRE, and if grep uses PCRE_NO_UTF8_CHECK, undefined 
behavior will result (maybe infinite loop, core dump, etc.).  We can't 
have undefined behavior in grep.  A simple fix is to avoid using 
PCRE_NO_UTF8_CHECK so I installed the attached patch to do that.  
Perhaps we can think of a better way at some point.  In the meantime I'm 
taking the liberty of closing Bug#17245 and Bug#16586.