Re: [PATCH 3/4] security/selinux: decrement sizeof size in strncmp

[Casey Schaufler <casey@schaufler-ca.com>]

Valdis.Kletnieks@vt.edu wrote:
> On Thu, 12 Nov 2009 18:11:55 PST, Casey Schaufler said:
>   
>> James Morris wrote:
>>     
>>> Do you see potential for a buffer overrun in this case?
>>>       
>
>   
>> No, but I hate arguing with people who think that every time
>> they see strcmp that they have found a security flaw.
>>     
>
> How do you feel about people who think every time they see strcmp()
> "Oh crap, something that needs auditing"? ;)
>   

They have my deep sympathy. Which is why I'm advocating leaving
the perfectly functional and correct use of strncmp() as it is.

> The biggest problem with strcmp() is that even if it got audited when that code
> went in, it's prone to unaudited breakage when somebody changes something in
> some other piece of code, quite often in some other .c file in some other
> directory.
>
> Julia, is there a way to use coccinelle to detect unsafe changes like that?  Or
> is expressing those semantics too difficult?
>
>
>