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From:   Paul Moore <paul@paul-moore.com>
Date:   Thu, 13 Oct 2022 18:47:42 -0400
Message-ID: <CAHC9VhR1kGT0+zM3smAQMEzGQLmVNhHu40f=YK3qavuYvcQYQQ@mail.gmail.com>
Subject: Re: [PATCH 0/9] integrity: Move hooks into LSM
To:     Kees Cook <keescook@chromium.org>
Cc:     Mimi Zohar <zohar@linux.ibm.com>,
        =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= <mic@digikod.net>,
        KP Singh <kpsingh@kernel.org>,
        Casey Schaufler <casey@schaufler-ca.com>,
        John Johansen <john.johansen@canonical.com>,
        James Morris <jmorris@namei.org>, linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        linux-integrity@vger.kernel.org, linux-hardening@vger.kernel.org
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On Thu, Oct 13, 2022 at 6:36 PM Kees Cook <keescook@chromium.org> wrote:
>
> Hi,
>
> It's been over 4 years since LSM stack was introduced. The integrity
> subsystem is long overdue for moving to this infrastructure. Here's my
> first pass at converting integrity and ima (and some of evm) into LSM
> hooks. This should be enough of an example to finish evm, and introduce
> the missing hooks for both. For example, after this, it looks like ima
> only has a couple places it's still doing things outside of the LSM. At
> least these stood out:
>
> fs/namei.c:     ima_post_create_tmpfile(mnt_userns, inode);
> fs/namei.c:                             ima_post_path_mknod(mnt_userns, dentry);
>
> Mimi, can you please take this series and finish the conversion for
> what's missing in ima and evm?
>
> I would also call attention to "175 insertions(+), 240 deletions(-)" --
> as expected, this is a net reduction in code.
>
> Thanks!

Without looking at any of the code, I just want to say this 100% gets
my vote; this is something we need to make happen at some point.

Thanks Kees!

> Kees Cook (9):
>   integrity: Prepare for having "ima" and "evm" available in "integrity"
>     LSM
>   security: Move trivial IMA hooks into LSM
>   ima: Move xattr hooks into LSM
>   ima: Move ima_file_free() into LSM
>   LSM: Introduce inode_post_setattr hook
>   fs: Introduce file_to_perms() helper
>   ima: Move ima_file_check() into LSM
>   integrity: Move trivial hooks into LSM
>   integrity: Move integrity_inode_get() out of global header
>
>  fs/attr.c                             |  3 +-
>  fs/file_table.c                       |  1 -
>  fs/namei.c                            |  2 -
>  fs/nfsd/vfs.c                         |  6 --
>  include/linux/evm.h                   |  6 --
>  include/linux/fs.h                    | 22 +++++++
>  include/linux/ima.h                   | 87 ---------------------------
>  include/linux/integrity.h             | 30 +--------
>  include/linux/lsm_hook_defs.h         |  3 +
>  security/Kconfig                      | 10 +--
>  security/apparmor/include/file.h      | 18 ++----
>  security/integrity/evm/evm_main.c     | 14 ++++-
>  security/integrity/iint.c             | 28 +++++++--
>  security/integrity/ima/ima.h          | 12 ++++
>  security/integrity/ima/ima_appraise.c | 21 +++++--
>  security/integrity/ima/ima_main.c     | 66 ++++++++++++++------
>  security/integrity/integrity.h        |  8 +++
>  security/security.c                   | 78 ++++++------------------
>  18 files changed, 175 insertions(+), 240 deletions(-)

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