Re: [PATCH] selinux: Annotate struct sidtab_str_cache with __counted_by

From: Kees Cook
Date: Fri Aug 18 2023 - 13:34:57 EST


On Fri, Aug 18, 2023 at 12:25:12PM -0400, Paul Moore wrote:
> On Thu, Aug 17, 2023 at 4:22 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >
> > Prepare for the coming implementation by GCC and Clang of the __counted_by
> > attribute. Flexible array members annotated with __counted_by can have
> > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> > functions).
> >
> > As found with Coccinelle[1], add __counted_by for struct sidtab_str_cache.
> >
> > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> >
> > Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
> > Cc: Stephen Smalley <stephen.smalley.work@xxxxxxxxx>
> > Cc: Eric Paris <eparis@xxxxxxxxxxxxxx>
> > Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
> > Cc: selinux@xxxxxxxxxxxxxxx
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > ---
> > security/selinux/ss/sidtab.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
>
> This also looks good to me, but similarly to the audit patch, since we
> are at -rc6 I'm going to wait to merge this until after the merge
> window. I'll send a follow up email once it's merged.

Thanks! Yeah, there's no rush. :)

--
Kees Cook