LSM: Ignore "security=" when "lsm=" is specified

To avoid potential confusion, explicitly ignore "security=" when "lsm=" is
used on the command line, and report that it is happening.

Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/security/security.c b/security/security.c
index b6bff646d373..ed9b8cbf21cf 100644
--- a/security/security.c
+++ b/security/security.c
@@ -288,9 +288,13 @@ static void __init ordered_lsm_init(void)
         ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms),
                                 GFP_KERNEL);
 
-        if (chosen_lsm_order)
+        if (chosen_lsm_order) {
+                if (chosen_major_lsm) {
+                        pr_info("security= is ignored because it is superseded by lsm=\n");
+                        chosen_major_lsm = NULL;
+                }
                 ordered_lsm_parse(chosen_lsm_order, "cmdline");
-        else
+        } else
                 ordered_lsm_parse(builtin_lsm_order, "builtin");
 
         for (lsm = ordered_lsms; *lsm; lsm++)