Since Kees Cook seems to be busy now, here is my version...
>From 885553e4793d9af2d4e9e99c7d137b0ec7b5f8ad Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Date: Tue, 19 Mar 2019 19:52:31 +0900
Subject: [PATCH] LSM: Revive CONFIG_DEFAULT_SECURITY_* for "make oldconfig"
Commit 70b62c25665f636c ("LoadPin: Initialize as ordered LSM") removed
CONFIG_DEFAULT_SECURITY_{SELINUX,SMACK,TOMOYO,APPARMOR,DAC} from
security/Kconfig and changed CONFIG_LSM to provide a fixed ordering as a
default value. That commit expected that existing users (upgrading from
Linux 5.0 and earlier) will edit CONFIG_LSM value in accordance with
their CONFIG_DEFAULT_SECURITY_* choice in their old kernel configs. But
since users might forget to edit CONFIG_LSM value, this patch revives
the choice (only for providing the default value for CONFIG_LSM) in order
to make sure that CONFIG_LSM reflects CONFIG_DEFAULT_SECURITY_* from their
old kernel configs.
Reported-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
security/Kconfig | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)
diff --git a/security/Kconfig b/security/Kconfig
index 1d6463f..743e594 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -239,9 +239,43 @@ source "security/safesetid/Kconfig"
source "security/integrity/Kconfig"
+choice
+ prompt "Default security module [superseded by 'Ordered list of enabled LSMs' below]"
+ default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
+ default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
+ default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
+ default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
+ default DEFAULT_SECURITY_DAC
+
+ help
+ This choice is there only for converting CONFIG_DEFAULT_SECURITY in old
+ kernel config to CONFIG_LSM in new kernel config. Don't change this choice
+ unless you are creating a fresh kernel config, for this choice will be
+ ignored after CONFIG_LSM is once defined.
+
+ config DEFAULT_SECURITY_SELINUX
+ bool "SELinux" if SECURITY_SELINUX=y
+
+ config DEFAULT_SECURITY_SMACK
+ bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
+
+ config DEFAULT_SECURITY_TOMOYO
+ bool "TOMOYO" if SECURITY_TOMOYO=y
+
+ config DEFAULT_SECURITY_APPARMOR
+ bool "AppArmor" if SECURITY_APPARMOR=y
+ config DEFAULT_SECURITY_DAC
+ bool "Unix Discretionary Access Controls"
+
+endchoice
+
config LSM
string "Ordered list of enabled LSMs"
- default "yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor"
+ default "yama,loadpin,safesetid,integrity,selinux" if DEFAULT_SECURITY_SELINUX
+ default "yama,loadpin,safesetid,integrity,smack" if DEFAULT_SECURITY_SMACK
+ default "yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO
+ default "yama,loadpin,safesetid,integrity,apparmor" if DEFAULT_SECURITY_APPARMOR
+ default "yama,loadpin,safesetid,integrity"
help
A comma-separated list of LSMs, in initialization order.
Any LSMs left off this list will be ignored. This can be
--
1.8.3.1
