GCC and pointer overflows [LWN.net]

[ken at krvw.com (Kenneth Van Wyk)]

FYI, here's an interesting article (and follow-on discussions) about a  
recent bug in the GCC compiler collection.

http://lwn.net/Articles/278137/

The bug, which has been documented in a CERT advisory, affects C code  
in which, under some circumstances, buffer bounds checking can be  
optimized out to produce binaries that are susceptible to buffer  
overflows.  The article includes a couple examples that really help  
illustrate the issue -- very interesting reading, IMHO.

Of course, many/most SC-Lers will no doubt jump on this as another  
example of why C is such a dangerous language to write (secure) code  
in, and that's fine.  But, I see the issue at least a little  
differently: a compiler making decisions for the programmer and  
producing executable code that does not accurately conform to what the  
programmer coded.  We've all heard of security-related optimizing  
issues for years, right?  Well, here's a prime example of one in action.


Cheers,

Ken

-----
Kenneth R. van Wyk
KRvW Associates, LLC
http://www.KRvW.com





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