Fix shift UB in php_ifd_get32s

diff --git a/ext/exif/exif.c b/ext/exif/exif.c
index 0ec5b1a1b820df5ba5974a786ffb794d109b9ca1..e8b52bc83f62f1a902f5b018588821d3f04aaa83 100644 (file)
--- a/ext/exif/exif.c
+++ b/ext/exif/exif.c
@@ -1457,28 +1457,29 @@ static signed short php_ifd_get16s(void *value, int motorola_intel)
 /* }}} */
 
 /* {{{ php_ifd_get32s
- * Convert a 32 bit signed value from file's native byte order */
-static int php_ifd_get32s(void *value, int motorola_intel)
+ * Convert a 32 bit unsigned value from file's native byte order */
+static unsigned php_ifd_get32u(void *void_value, int motorola_intel)
 {
+       uchar *value = (uchar *) void_value;
        if (motorola_intel) {
-               return  (((char  *)value)[0] << 24)
-                         | (((uchar *)value)[1] << 16)
-                         | (((uchar *)value)[2] << 8 )
-                         | (((uchar *)value)[3]      );
+               return  ((unsigned)value[0] << 24)
+                         | ((unsigned)value[1] << 16)
+                         | ((unsigned)value[2] << 8 )
+                         | ((unsigned)value[3]      );
        } else {
-               return  (((char  *)value)[3] << 24)
-                         | (((uchar *)value)[2] << 16)
-                         | (((uchar *)value)[1] << 8 )
-                         | (((uchar *)value)[0]      );
+               return  ((unsigned)value[3] << 24)
+                         | ((unsigned)value[2] << 16)
+                         | ((unsigned)value[1] << 8 )
+                         | ((unsigned)value[0]      );
        }
 }
 /* }}} */
 
 /* {{{ php_ifd_get32u
- * Write 32 bit unsigned value to data */
-static unsigned php_ifd_get32u(void *value, int motorola_intel)
+ * Convert a 32 bit signed value from file's native byte order */
+static unsigned php_ifd_get32s(void *value, int motorola_intel)
 {
-       return (unsigned)php_ifd_get32s(value, motorola_intel) & 0xffffffff;
+       return (int) php_ifd_get32u(value, motorola_intel);
 }
 /* }}} */