1 files changed, 19 insertions, 0 deletions

diff --git a/security/security.c b/security/security.c
index b9fea3999cf8..38316bb28b16 100644
--- a/security/security.c
+++ b/security/security.c
@@ -25,6 +25,7 @@
 #include <linux/mount.h>
 #include <linux/personality.h>
 #include <linux/backing-dev.h>
+#include <linux/string.h>
 #include <net/flow.h>
 
 #define MAX_LSM_EVM_XATTR       2
@@ -86,6 +87,21 @@ static int __init choose_lsm(char *str)
 }
 __setup("security=", choose_lsm);
 
+static bool match_last_lsm(const char *list, const char *lsm)
+{
+        const char *last;
+
+        if (WARN_ON(!list || !lsm))
+                return false;
+        last = strrchr(list, ',');
+        if (last)
+                /* Pass the comma, strcmp() will check for '\0' */
+                last++;
+        else
+                last = list;
+        return !strcmp(last, lsm);
+}
+
 static int lsm_append(char *new, char **result)
 {
         char *cp;
@@ -93,6 +109,9 @@ static int lsm_append(char *new, char **result)
         if (*result == NULL) {
                 *result = kstrdup(new, GFP_KERNEL);
         } else {
+                /* Check if it is the last registered name */
+                if (match_last_lsm(*result, new))
+                        return 0;
                 cp = kasprintf(GFP_KERNEL, "%s,%s", *result, new);
                 if (cp == NULL)
                         return -ENOMEM;