Super Lint (was: Unexecutable Stack / Buffer Overflow Exploits...)

[Kai Henningsen]

[e-mail] (Magnus Danielson)  wrote on 01.01.00 in <[e-mail]>:

> Oh yes... like those that those who avoid strcpy by doing
>
>    memcpy(t, s, strlen(s)+1)
>
> I mean, memcpy is supposed to be safe, ain't it ;)

I guess what we _really_ need is some sort of super lint. That is, a  
program that can analyze C code (others are fine, but C is the most  
important by far) and highlights problematic points in the code.

And then there should be some sort of pseudo-comment which you can use to  
explain properties of, say, pointed-to data, to possibly allow the super  
lint to find out that the code is safe after all - except that somewhere  
else, you violated those properties.

Note that this is NOT full program proof, which is far harder to get  
right. You only want to prove that you don't overrun buffers and (while  
we're at it) that you don't use unchecked data in critical places (what  
Perl taint checking tests).

This would not mean that your program actually does anything useful, only  
that it's safe against some kinds of attack.

And it would have zero runtime overhead.

MfG Kai