Re: [PATCH v6 7/7] ima: add policy support for the new file open MAY_OPENEXEC flag

From: Kees Cook
Date: Thu Jul 16 2020 - 15:12:55 EST


On Thu, Jul 16, 2020 at 04:40:15PM +0200, MickaÃl SalaÃn wrote:
>
> On 15/07/2020 22:40, Kees Cook wrote:
> > On Tue, Jul 14, 2020 at 08:16:38PM +0200, MickaÃl SalaÃn wrote:
> >> From: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> >>
> >> The kernel has no way of differentiating between a file containing data
> >> or code being opened by an interpreter. The proposed O_MAYEXEC
> >> openat2(2) flag bridges this gap by defining and enabling the
> >> MAY_OPENEXEC flag.
> >>
> >> This patch adds IMA policy support for the new MAY_OPENEXEC flag.
> >>
> >> Example:
> >> measure func=FILE_CHECK mask=^MAY_OPENEXEC
> >> appraise func=FILE_CHECK appraise_type=imasig mask=^MAY_OPENEXEC
> >>
> >> Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> >> Reviewed-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
> >> Acked-by: MickaÃl SalaÃn <mic@xxxxxxxxxxx>
> >
> > (Process nit: if you're sending this on behalf of another author, then
> > this should be Signed-off-by rather than Acked-by.)
>
> I'm not a co-author of this patch.

Correct, but you are part of the delivery path to its entry to the
tree. If you were co-author, you would include "Co-developed-by" with
a Signed-off-by. (So my nit stands)

For excruciating details:

https://www.kernel.org/doc/html/latest/process/submitting-patches.html#when-to-use-acked-by-cc-and-co-developed-by

"The Signed-off-by: tag indicates that the signer was ... in the patchâs
delivery path."

"Co-developed-by: ... is a used to give attribution to co-authors ..."

--
Kees Cook