[TUHS] Clueless programmers

Larry McVoy lm at mcvoy.com
Sat Feb 17 02:32:00 AEST 2018


We had the same problem that was uncovered by a naive programmer "removing
unneeded whitespaces".  Moved some stuff around and exposed a buffer overrun.

On Fri, Feb 16, 2018 at 10:54:50PM +0700, Rudi Blom wrote:
> Clueless or careless?
> 
> A customer program worked for many years till one of the transaction
> messages had a few bytes added.
> 
> Looking into it I discovered that the program had only worked because
> the receive buffer was followed by another buffer which was used in a
> later sequence. Only when also that buffer overflowed some critical
> integers got overwritten and used as index in tables that gave a lot
> of fun.
> 
> Well, as all here know, C is fun :-)

-- 
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Larry McVoy            	     lm at mcvoy.com             http://www.mcvoy.com/lm 


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