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>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e59e1471d4db8da8a5e2c3e8ba623465e63a9e77..91c0251fdb8664ad40c8f808203299f1c795ac7f 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2321,7 +2321,7 @@
 
        lsm=lsm1,...,lsmN
                        [SECURITY] Choose order of LSM initialization. This
-                       overrides CONFIG_LSM.
+                       overrides CONFIG_LSM, and the "security=" parameter.
 
        machvec=        [IA-64] Force the use of a particular machine-vector
                        (machvec) in a generic kernel.
@@ -4094,11 +4094,9 @@
                        Note: increases power consumption, thus should only be
                        enabled if running jitter sensitive (HPC/RT) workloads.
 
-       security=       [SECURITY] Choose a security module to enable at boot.
-                       If this boot parameter is not specified, only the first
-                       security module asking for security registration will be
-                       loaded. An invalid security module name will be treated
-                       as if no module has been chosen.
+       security=       [SECURITY] Choose a legacy "major" security module to
+                       enable at boot. This has been deprecated by the
+                       "lsm=" parameter.
 
        selinux=        [SELINUX] Disable or enable SELinux at boot time.
                        Format: { "0" | "1" }

diff --git a/security/security.c b/security/security.c
index b6bff646d373ff31826c725aab30fa260ce07089..ed9b8cbf21cf735b43208e945d96b1f065bbd4e9 100644 (file)
--- 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++)