check for overlapping pointers

1 files changed, 2 insertions, 0 deletions

diff --git a/src/stdio/fscanf_s.c b/src/stdio/fscanf_s.c
index 4d01ba5e..310ca5da 100644
--- a/src/stdio/fscanf_s.c
+++ b/src/stdio/fscanf_s.c
@@ -1,11 +1,13 @@
 #include <stdio.h>
 #include <stdarg.h>
+#include <string.h>
 #include "_stdio.h"
 
 /** read formatted input from a file stream **/
 int fscanf_s(FILE * restrict stream, const char * restrict format, ...)
 {
 	SIGNAL_SAFE(0);
+	ASSERT_NOOVERLAP(stream, sizeof(*stream), format, strlen(format));
 	va_list ap;
 	va_start(ap, format);
 	int ret = vfscanf_s(stream, format, ap);