--- head/usr.bin/patch/patch.c	
+++ head/usr.bin/patch/patch.c	
@@ -1026,6 +1026,9 @@ 
 	const char	*plineptr;
 	unsigned short	plinelen;
 
+	/* Patch does not match if we don't have anymore context to use */
+	if (pline > pat_lines)
+		return false;
 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
 		ilineptr = ifetch(iline, offset >= 0);
 		if (ilineptr == NULL)