userns: refuse empty userns names

Let's tighten rules a bit.

diff --git a/src/nsresourced/userns-registry.c b/src/nsresourced/userns-registry.c
index d69348aae71916c18fa3816a352c0e558ffa864a..b1754b51fe7689dc83711872a06c9e709afacf96 100644 (file)
--- a/src/nsresourced/userns-registry.c
+++ b/src/nsresourced/userns-registry.c
@@ -592,6 +592,9 @@ bool userns_name_is_valid(const char *name) {
 
         /* Checks if the specified string is suitable as user namespace name. */
 
+        if (isempty(name))
+                return false;
+
         if (strlen(name) > NAME_MAX) /* before we use alloca(), let's check for size */
                 return false;