Re: [v2,0/3] module: Add compile-time check for embedded NUL characters

[Kees Cook <kees@kernel.org>]

On Tue, Oct 14, 2025 at 08:24:00AM +0200, Ricardo Ribalda wrote:
> Hi Kees
> 
> Thanks for the report.
> 
> 
> On Tue, 14 Oct 2025 at 07:41, Kees Cook <kees@kernel.org> wrote:
> >
> >
> >
> > On October 13, 2025 1:34:20 PM PDT, Patchwork Integration <patchwork@media-ci.org> wrote:
> > >Dear Kees Cook:
> > >
> > >Thanks for your patches! Unfortunately the Media CI robot detected some
> > >issues:
> > >
> > ># Test static:test-smatch
> > >
> > >drivers/media/usb/usbtv/usbtv-core.c:157:1: error: bad constant expression
> >
> > Where can I find what this test actually does?
> >
> > >For more details, check the full report at:
> > >https://linux-media.pages.freedesktop.org/-/users/patchwork/-/jobs/85913402/artifacts/report.htm .
> >
> > This webserver appears to be misconfigured to send compressed output without the right headers? I can't actually view this URL.
> 
> I will follow-up with fdo maintainers to figure out what happened.
> there. On the meantime you can use these url that seems to work:
> https://linux-media.pages.freedesktop.org/-/users/patchwork/-/jobs/85913402/artifacts/report.txt
> https://gitlab.freedesktop.org/linux-media/users/patchwork/-/jobs/85913398
> 
> Basically sparse/smatch do not seem to understand the constant.

Yeah, I managed to find the actual scripts that are run for the
static-sparse/smatch tests. It looks like those tools aren't correctly
handling string literals for __builtin_strlen(), which is a constant for
constant arguments.

So, that's a C parsing bug in those tools (GCC and Clang are fine).

-Kees

-- 
Kees Cook