1 files changed, 5 insertions, 2 deletions
diff --git a/libc/misc/ftw/ftw.c b/libc/misc/ftw/ftw.c
index 833821f22..605e07cd5 100644
--- a/libc/misc/ftw/ftw.c
+++ b/libc/misc/ftw/ftw.c
@@ -492,11 +492,14 @@ ftw_startup (const char *dir, int is_nftw, void *func, int descriptors, int flag
     char *cp;
 
     /* First make sure the parameters are reasonable.  */
-    if (dir[0] == '\0')
-    {
+    if (unlikely(dir==NULL || *dir=='\0')) {
 	__set_errno (ENOENT);
 	return -1;
     }
+    if ((strlen(dir)+1) > NAME_MAX) {
+	__set_errno(ENAMETOOLONG);
+	return -1;
+    }
 
     data.maxdir = descriptors < 1 ? 1 : descriptors;
     data.actdir = 0;