IMA: use audit_log_untrusted_string rather than %s

Convert all of the places IMA calls audit_log_format with %s into
audit_log_untrusted_string().  This is going to cause them all to get
quoted, but it should make audit log injection harder.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 20 insertions, 13 deletions

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index babc5009756d..778a735621f1 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -255,6 +255,13 @@ static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
         return result;
 }
 
+static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
+{
+        audit_log_format(ab, "%s=", key);
+        audit_log_untrustedstring(ab, value);
+        audit_log_format(ab, " ");
+}
+
 static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
 {
         struct audit_buffer *ab;
@@ -277,7 +284,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                 token = match_token(p, policy_tokens, args);
                 switch (token) {
                 case Opt_measure:
-                        audit_log_format(ab, "%s ", "measure");
+                        ima_log_string(ab, "action", "measure");
 
                         if (entry->action != UNKNOWN)
                                 result = -EINVAL;
@@ -285,7 +292,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                         entry->action = MEASURE;
                         break;
                 case Opt_dont_measure:
-                        audit_log_format(ab, "%s ", "dont_measure");
+                        ima_log_string(ab, "action", "dont_measure");
 
                         if (entry->action != UNKNOWN)
                                 result = -EINVAL;
@@ -293,7 +300,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                         entry->action = DONT_MEASURE;
                         break;
                 case Opt_func:
-                        audit_log_format(ab, "func=%s ", args[0].from);
+                        ima_log_string(ab, "func", args[0].from);
 
                         if (entry->func)
                                 result  = -EINVAL;
@@ -313,7 +320,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                                 entry->flags |= IMA_FUNC;
                         break;
                 case Opt_mask:
-                        audit_log_format(ab, "mask=%s ", args[0].from);
+                        ima_log_string(ab, "mask", args[0].from);
 
                         if (entry->mask)
                                 result = -EINVAL;
@@ -332,7 +339,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                                 entry->flags |= IMA_MASK;
                         break;
                 case Opt_fsmagic:
-                        audit_log_format(ab, "fsmagic=%s ", args[0].from);
+                        ima_log_string(ab, "fsmagic", args[0].from);
 
                         if (entry->fsmagic) {
                                 result = -EINVAL;
@@ -345,7 +352,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                                 entry->flags |= IMA_FSMAGIC;
                         break;
                 case Opt_uid:
-                        audit_log_format(ab, "uid=%s ", args[0].from);
+                        ima_log_string(ab, "uid", args[0].from);
 
                         if (entry->uid != -1) {
                                 result = -EINVAL;
@@ -362,44 +369,44 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
                         }
                         break;
                 case Opt_obj_user:
-                        audit_log_format(ab, "obj_user=%s ", args[0].from);
+                        ima_log_string(ab, "obj_user", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
                                                    LSM_OBJ_USER,
                                                    AUDIT_OBJ_USER);
                         break;
                 case Opt_obj_role:
-                        audit_log_format(ab, "obj_role=%s ", args[0].from);
+                        ima_log_string(ab, "obj_role", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
                                                    LSM_OBJ_ROLE,
                                                    AUDIT_OBJ_ROLE);
                         break;
                 case Opt_obj_type:
-                        audit_log_format(ab, "obj_type=%s ", args[0].from);
+                        ima_log_string(ab, "obj_type", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
                                                    LSM_OBJ_TYPE,
                                                    AUDIT_OBJ_TYPE);
                         break;
                 case Opt_subj_user:
-                        audit_log_format(ab, "subj_user=%s ", args[0].from);
+                        ima_log_string(ab, "subj_user", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
                                                    LSM_SUBJ_USER,
                                                    AUDIT_SUBJ_USER);
                         break;
                 case Opt_subj_role:
-                        audit_log_format(ab, "subj_role=%s ", args[0].from);
+                        ima_log_string(ab, "subj_role", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
                                                    LSM_SUBJ_ROLE,
                                                    AUDIT_SUBJ_ROLE);
                         break;
                 case Opt_subj_type:
-                        audit_log_format(ab, "subj_type=%s ", args[0].from);
+                        ima_log_string(ab, "subj_type", args[0].from);
                         result = ima_lsm_rule_init(entry, args[0].from,
                                                    LSM_SUBJ_TYPE,
                                                    AUDIT_SUBJ_TYPE);
                         break;
                 case Opt_err:
+                        ima_log_string(ab, "UNKNOWN", p);
                         result = -EINVAL;
-                        audit_log_format(ab, "UNKNOWN=%s ", p);
                         break;
                 }
         }