Fix GH-16322: imageaffine overflow on affine argument.

Author: devnexen

ext/gd/gd.c

@@ -3687,13 +3687,25 @@ PHP_FUNCTION(imageaffine)
 		if ((zval_affine_elem = zend_hash_index_find(Z_ARRVAL_P(z_affine), i)) != NULL) {
 			switch (Z_TYPE_P(zval_affine_elem)) {
 				case IS_LONG:
-					affine[i]  = Z_LVAL_P(zval_affine_elem);
+					affine[i] = Z_LVAL_P(zval_affine_elem);
+					if (affine[i] < INT_MIN || affine[i] > INT_MAX) {
+						zend_argument_value_error(2, "element %i must be between %d and %d", i, INT_MIN, INT_MAX);
+						RETURN_THROWS();
+					}
 					break;
 				case IS_DOUBLE:
 					affine[i] = Z_DVAL_P(zval_affine_elem);
+					if (affine[i] < INT_MIN || affine[i] > INT_MAX) {
+						zend_argument_value_error(2, "element %i must be between %d and %d", i, INT_MIN, INT_MAX);
+						RETURN_THROWS();
+					}
 					break;
 				case IS_STRING:
 					affine[i] = zval_get_double(zval_affine_elem);
+					if (affine[i] < INT_MIN || affine[i] > INT_MAX) {
+						zend_argument_value_error(2, "element %i must be between %d and %d", i, INT_MIN, INT_MAX);
+						RETURN_THROWS();
+					}
 					break;
 				default:
 					zend_argument_type_error(3, "contains invalid type for element %i", i);

ext/gd/tests/gh16322.phpt

@@ -0,0 +1,29 @@
+--TEST--
+GH-16322 (imageaffine overflow/underflow on affine matrix)
+--EXTENSIONS--
+gd
+--INI--
+memory_limit=-1
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 8) die('skip this test is for 64bit platforms only'); ?>
+--FILE--
+<?php
+$matrix = [PHP_INT_MAX, 1, 1, 1, 1, 1];
+$src = imagecreatetruecolor(8, 8);
+
+try {
+	imageaffine($src, $matrix);
+} catch (\ValueError $e) {
+	echo $e->getMessage() . PHP_EOL;
+}
+$matrix[0] = 1;
+$matrix[3] = PHP_INT_MIN;
+try {
+	imageaffine($src, $matrix);
+} catch (\ValueError $e) {
+	echo $e->getMessage();
+}
+?>
+--EXPECTF--
+imageaffine(): Argument #2 ($affine) element 0 must be between %s and %d
+imageaffine(): Argument #2 ($affine) element 3 must be between %s and %d