[PATCH v2 3/3] security: Add LSMs dependencies to CONFIG_LSM
omosnace at redhat.com
Mon Feb 15 19:03:29 UTC 2021
On Mon, Feb 15, 2021 at 7:17 PM Mickaël Salaün <mic at digikod.net> wrote:
> From: Mickaël Salaün <mic at linux.microsoft.com>
> Thanks to the previous commit, this gives the opportunity to users, when
> running make oldconfig, to update the list of enabled LSMs at boot time
> if an LSM has just been enabled or disabled in the build. Moreover,
> this list only makes sense if at least one LSM is enabled.
> Cc: Casey Schaufler <casey at schaufler-ca.com>
> Cc: James Morris <jmorris at namei.org>
> Cc: Masahiro Yamada <masahiroy at kernel.org>
> Cc: Serge E. Hallyn <serge at hallyn.com>
> Signed-off-by: Mickaël Salaün <mic at linux.microsoft.com>
> Link: https://email@example.com
> Changes since v1:
> * Add CONFIG_SECURITY as a dependency of CONFIG_LSM. This prevent an
> error when building without any LSMs.
> security/Kconfig | 4 ++++
> 1 file changed, 4 insertions(+)
> diff --git a/security/Kconfig b/security/Kconfig
> index 7561f6f99f1d..addcc1c04701 100644
> --- a/security/Kconfig
> +++ b/security/Kconfig
> @@ -277,6 +277,10 @@ endchoice
> config LSM
> string "Ordered list of enabled LSMs"
> + depends on SECURITY || SECURITY_LOCKDOWN_LSM || SECURITY_YAMA || \
> + SECURITY_LOADPIN || SECURITY_SAFESETID || INTEGRITY || \
> + SECURITY_SELINUX || SECURITY_SMACK || SECURITY_TOMOYO || \
> + SECURITY_APPARMOR || BPF_LSM
This looks really awkward, since all of these already depend on
SECURITY (if not, it's a bug)... I guarantee you that after some time
someone will come, see that the weird boolean expression is equivalent
to just SECURITY, and simplify it.
I assume the new mechanism wouldn't work as intended if there is just
SECURITY? If not, then maybe you should rather specify this value
dependency via some new field rather than abusing "depends on" (say,
"value depends on"?). The fact that a seemingly innocent change to the
config definition breaks your mechanism suggests that the design is
I do think this would be a useful feature, but IMHO shouldn't be
implemented like this.
> default "lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
> default "lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
> default "lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
Software Engineer, Linux Security - SELinux kernel
Red Hat, Inc.
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