librasan: Remove optimized strlen

Author: wfdewith

libafl_qemu/librasan/asan/cc/src/strlen.c

@@ -25,28 +25,16 @@
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * Parentheses have been added to HASZERO macro to fix compiler warning.
+ * The optimized version that checks for null bytes per word has been removed,
+ * since it can overread the buffer if the null terminator is not the last byte
+ * of the buffer.
  */
 
 #include <string.h>
-#include <stdint.h>
-#include <limits.h>
-
-#define ALIGN (sizeof(size_t))
-#define ONES ((size_t)-1/UCHAR_MAX)
-#define HIGHS (ONES * (UCHAR_MAX/2+1))
-#define HASZERO(x) (((x)-ONES) & ~(x) & HIGHS)
 
 size_t strlen(const char *s)
 {
 	const char *a = s;
-#ifdef __GNUC__
-	typedef size_t __attribute__((__may_alias__)) word;
-	const word *w;
-	for (; (uintptr_t)s % ALIGN; s++) if (!*s) return s-a;
-	for (w = (const void *)s; !HASZERO(*w); w++);
-	s = (const void *)w;
-#endif
 	for (; *s; s++);
 	return s-a;
 }