libudev: enumerate: fix NULL-deref for subsystem-matches

[elogind.git] / src / libudev / libudev-enumerate.c

diff --git a/src/libudev/libudev-enumerate.c b/src/libudev/libudev-enumerate.c
index b96e5b278fa0f13b84450042b15e7ad949c39035..385829d464345bf96705c358e9f26152f725f96d 100644 (file)
--- a/src/libudev/libudev-enumerate.c
+++ b/src/libudev/libudev-enumerate.c
@@ -721,6 +721,8 @@ static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *s
 {
         struct udev_list_entry *list_entry;
 
+        subsystem = subsystem ? : "";
+
         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
                         return false;