Re: [PATCH] vt: Fix potential read overflow of kernel memory

[Kees Cook]

On Thu, Aug 31, 2023 at 07:32:18AM +0200, Jiri Slaby wrote:
> On 30. 08. 23, 23:28, Kees Cook wrote:
> >                  len = strlcpy(kbs, func_table[kb_func] ? : "", len);
> > 
> > This is the anti-pattern (take the length of the _source_) we need to
> > remove.
> 
> But len is the length of kbs, i.e. the destination. Or what am I missing?

strlcpy() returns the length of the _source_ string (i.e. it could be
greater than the input argument len). But there is no current flaw here
(since all sources are very short). We're just trying to remove strlcpy()
since it leads to unexpected results.

-Kees

-- 
Kees Cook