com php-src: Fix #72482: Ilegal write/read access caused by gdImageAALine overflow: ext/gd/libgd/gd.c ext/gd/tests/bug72482.phpt
ext/gd/tests/bug72482_2.phpt ext/gd/tests/bug 72482_2.png

Commit: 6499581af76cfe986e12330faabb3a7c36d45ffc Author: Christoph M. Becker <cmbecker69@gmx.de> Tue, 25 Oct 2016 15:14:22 +0200 Committer: Stanislav Malyshev <stas@php.net> Sun, 30 Oct 2016 14:28:23 -0700 Parents: f74d7d92c8bc1edc2505e0b58546217e9e1ecb40 Branches: PHP-5.6 PHP-7.0 PHP-7.1 master Link: http://git.php.net/?p=php-src..git;a=commitdiff;h=6499581af76cfe986e12330faabb3a7c36d45ffc Log: Fix #72482: Ilegal write/read access caused by gdImageAALine overflow Instead of rolling our own bounds check we use clip_1d() as it's done in gdImageLine() and in external libgd. We must not pass the image width and height, respectively, but rather the largest ordinate value that is allowed to be accessed, i.e. width-1 and height-1, respectively. Bugs: https://bugs.php.net/72482 Changed paths: M ext/gd/libgd/gd.c A ext/gd/tests/bug72482.phpt A ext/gd/tests/bug72482_2.phpt A ext/gd/tests/bug72482_2.png Diff: diff --git a/ext/gd/libgd/gd..c b/ext/gd/libgd/gd.c index 033d4fa..058f1c9 100644 --- a/ext/gd/libgd/gd.c +++ b/ext/gd/libgd/gd.c @@ -1117,7 +1117,7 @@ void gdImageLine (gdImagePtr im, int x1, int y1, int x2, int y2, int color) } /* 2.0.10: Nick Atty: clip to edges of drawing rectangle, return if no points need to be drawn */ - if (!clip_1d(&x1,&y1,&x2,&y2,gdImageSX(im)) || !clip_1d(&y1,&x1,&y2,&x2,gdImageSY(im))) { + if (!clip_1d(&x1,&y1,&x2,&y2,gdImageSX(im)-1) || !clip_1d(&y1,&x1,&y2,&x2,gdImageSY(im)-1)) { return; } @@ -1301,55 +1301,10 @@ void gdImageAALine (gdImagePtr im, int x1, int y1, int x2, int y2, int col) long x, y, inc, frac; long dx, dy,tmp; - if (y1 < 0 && y2 < 0) { - return; - } - if (y1 < 0) { - x1 += (y1 * (x1 - x2)) / (y2 - y1); - y1 = 0; - } - if (y2 < 0) { - x2 += (y2 * (x1 - x2)) / (y2 - y1); - y2 = 0; - } - - /* bottom edge */ - if (y1 >= im->sy && y2 >= im->sy) { - return; - } - if (y1 >= im->sy) { - x1 -= ((im->sy - y1) * (x1 - x2)) / (y2 - y1); - y1 = im->sy - 1; - } - if (y2 >= im->sy) { - x2 -= ((im->sy - y2) * (x1 - x2)) / (y2 - y1); - y2 = im->sy - 1; - } - - /* left edge */ - if (x1 < 0 && x2 < 0) { - return; - } - if (x1 < 0) { - y1 += (x1 * (y1 - y2)) / (x2 - x1); - x1 = 0; - } - if (x2 < 0) { - y2 += (x2 * (y1 - y2)) / (x2 - x1); - x2 = 0; - } - /* right edge */ - if (x1 >= im->sx && x2 >= im->sx) { + /* 2.0.10: Nick Atty: clip to edges of drawing rectangle, return if no points need to be drawn */ + if (!clip_1d(&x1,&y1,&x2,&y2,gdImageSX(im)-1) || !clip_1d(&y1,&x1,&y2,&x2,gdImageSY(im)-1)) { return; } - if (x1 >= im->sx) { - y1 -= ((im->sx - x1) * (y1 - y2)) / (x2 - x1); - x1 = im->sx - 1; - } - if (x2 >= im->sx) { - y2 -= ((im->sx - x2) * (y1 - y2)) / (x2 - x1); - x2 = im->sx - 1; - } dx = x2 - x1; dy = y2 - y1; diff --git a/ext/gd/tests/bug72482.phpt b/ext/gd/tests/bug72482.phpt new file mode 100644 index 0000000..548921d --- /dev/null +++ b/ext/gd/tests/bug72482.phpt @@ -0,0 +1,19 @@ +--TEST-- +Bug #72482 (Ilegal write/read access caused by gdImageAALine overflow) +--SKIPIF-- +<?php +if (!extension_loaded('gd')) die('skip gd extension not available'); +?> +--FILE-- +<?php +$img = imagecreatetruecolor(13, 1007); +imageantialias($img, true); +imageline($img, 0, 0, 1073745919, 1073745919, 4096); + +$img = imagecreatetruecolor(100, 100); +imageantialias($img, true); +imageline($img, 1094795585, 0, 2147483647, 255, 0xff); +?> +===DONE=== +--EXPECT-- +===DONE=== diff --git a/ext/gd/tests/bug72482_2.phpt b/ext/gd/tests/bug72482_2.phpt new file mode 100644 index 0000000..a8a08fa --- /dev/null +++ b/ext/gd/tests/bug72482_2.phpt @@ -0,0 +1,21 @@ +--TEST-- +Bug 72482 (Ilegal write/read access caused by gdImageAALine overflow) +--SKIPIF-- +<?php +if (!extension_loaded('gd')) die('skip gd extension not available'); +?> +--FILE-- +<?php +require_once __DIR__ . DIRECTORY_SEPARATOR . 'func.inc'; + +$im = imagecreatetruecolor(10, 10); +imagefilledrectangle($im, 0, 0, 9, 9, imagecolorallocate($im, 255, 255, 255)); +imageantialias($im, true); +imageline($im, 0, 0, 10, 10, imagecolorallocate($im, 0, 0, 0)); + +test_image_equals_file(__DIR__ . DIRECTORY_SEPARATOR . 'bug72482_2.png', $im); +?> +===DONE=== +--EXPECT-- +The images are equal. +===DONE=== diff --git a/ext/gd/tests/bug72482_2.png b/ext/gd/tests/bug72482_2.png new file mode 100644 index 0000000..da90b2a Binary files /dev/null and b/ext/gd/tests/bug72482_2.png differ