Vulnerability Development mailing list archives

Re: Smashing the Stack?


From: fila <fila () detack de>
Date: Thu, 18 Jul 2002 11:12:46 +0300

On Thursday 18 July 2002 02:28 am, yatima wrote:
The discrepancy you are seeing is merely an artifact that dates
Aleph1's article. GCC has changed quite a bit since, try not to get
hung up on those details. I know its difficult when following step by
step :-). As you continue, you will begin to see how blind compilers
are. Although GCC is pretty phat, it is pretty damn blind, and has to
make many assumptions. Aleph1's article is the most common, but I
REALLY suggest taking a look at Mixter's paper:
http://www.11a.nu/stack/exploit.txt


the real question is how did the gcc developers come to this solution ?
I mean ... it looks pretty stupid. for a 3 chars buffer the compiler 
alocates 24 bytes and for a 4 chars buff only 4 bytes ?!?!?!
the same problem you encounter if you go further with your exploration:
for a 7 chars buff -> 24 bytes
for a 8 chars buff -> 8 bytes :)))))))))))

isn't it dumb ? it's been allready a pretty long time since I keep 
looking for somebody to explain why does the gcc alocate space in this 
manner.

Fila


Current thread: