Re: [PATCH] fortify: Adjust KUnit test for modular build

From: Kees Cook
Date: Wed Sep 14 2022 - 09:59:45 EST


On Wed, Sep 14, 2022 at 06:13:59PM +0800, David Gow wrote:
> On Wed, Sep 14, 2022 at 1:31 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >
> > A much better "unknown size" string pointer is available directly from
> > struct test, so use that instead of a global that isn't shared with
> > modules.
> >
> > Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > Link: https://lore.kernel.org/lkml/YyCOHOchVuE/E7vS@dev-arch.thelio-3990X
> > Fixes: 875bfd5276f3 ("fortify: Add KUnit test for FORTIFY_SOURCE internals")
> > Cc: linux-hardening@xxxxxxxxxxxxxxx
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > ---
> > Whoops! Thanks Nathan! :) This fixes it for your reproducer.
>
> Ah, this is better than saved_command_line, IMO. I don't think it'd
> necessarily be a _disaster_ to just introduce a new dynamically-sized
> string here, which would be more explicit, but test->name is at least
> obviously related to this file anyway.

Yeah, and I'm trying to explicitly use a string that the compiler won't
immediately be able to see through, so best to get it from an external
source.

> Reviewed-by: David Gow <davidgow@xxxxxxxxxx>

Thanks!

-Kees

--
Kees Cook