Fix possible double free

Author: Andras Fekete

wolfcrypt/src/asn.c

@@ -37514,8 +37514,10 @@ int wc_MIME_parse_headers(char* in, int inLen, MimeHdr** headers)
             }
             else if (mimeStatus == MIME_BODYVAL && cur == ';' && pos >= 1) {
                 end = pos-1;
-                if (bodyVal != NULL)
+                if (bodyVal != NULL) {
                     XFREE(bodyVal, NULL, DYNAMIC_TYPE_PKCS7);
+                    bodyVal = NULL;
+                }
                 ret = wc_MIME_header_strip(curLine, &bodyVal, start, end);
                 if (ret) {
                     goto error;
@@ -37608,9 +37610,12 @@ int wc_MIME_parse_headers(char* in, int inLen, MimeHdr** headers)
     if (ret != 0)
         wc_MIME_free_hdrs(curHdr);
     wc_MIME_free_hdrs(nextHdr);
-    XFREE(nameAttr, NULL, DYNAMIC_TYPE_PKCS7);
-    XFREE(bodyVal, NULL, DYNAMIC_TYPE_PKCS7);
-    XFREE(nextParam, NULL, DYNAMIC_TYPE_PKCS7);
+    if (nameAttr != NULL)
+        XFREE(nameAttr, NULL, DYNAMIC_TYPE_PKCS7);
+    if (bodyVal != NULL)
+        XFREE(bodyVal, NULL, DYNAMIC_TYPE_PKCS7);
+    if (nextParam != NULL)
+        XFREE(nextParam, NULL, DYNAMIC_TYPE_PKCS7);
 
     return ret;
 }