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Date:   Thu, 20 Oct 2022 16:04:22 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Casey Schaufler <casey@schaufler-ca.com>
Cc:     Mimi Zohar <zohar@linux.ibm.com>,
        John Johansen <john.johansen@canonical.com>,
        Paul Moore <paul@paul-moore.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        linux-security-module@vger.kernel.org,
        =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= <mic@digikod.net>,
        KP Singh <kpsingh@kernel.org>, linux-kernel@vger.kernel.org,
        linux-integrity@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 6/9] fs: Introduce file_to_perms() helper
Message-ID: <202210201603.45E53CAF@keescook>
References: <20221013222702.never.990-kees@kernel.org>
 <20221013223654.659758-6-keescook@chromium.org>
 <34084e9a-b4c0-95b7-1132-ca95294c8063@schaufler-ca.com>
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On Thu, Oct 20, 2022 at 10:29:08AM -0700, Casey Schaufler wrote:
> On 10/13/2022 3:36 PM, Kees Cook wrote:
> > Extract the logic used by LSM file hooks to be able to reconstruct the
> > access mode permissions from an open.
> >
> > Cc: John Johansen <john.johansen@canonical.com>
> > Cc: Paul Moore <paul@paul-moore.com>
> > Cc: James Morris <jmorris@namei.org>
> > Cc: "Serge E. Hallyn" <serge@hallyn.com>
> > Cc: linux-security-module@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  include/linux/fs.h               | 22 ++++++++++++++++++++++
> >  security/apparmor/include/file.h | 18 ++++--------------
> >  2 files changed, 26 insertions(+), 14 deletions(-)
> 
> Smack uses its own definitions for MAY_SOMETHING. Making
> AppArmor's values global is going to clash. If you want to
> do this there needs to be a grand consolidation. It could
> go in security/lsm_hooks.h. I can't see anyone other than
> Smack wanting MAY_LOCK, so I can't say the concept really
> makes much sense.

I left AppArmor's special ones in apparmor/. This only lifts the common
pre-existing global VFS MAY_* flags. (And only the low nibble's worth).

-- 
Kees Cook