diff --git a/ext/gd/gd_ctx.c b/ext/gd/gd_ctx.c index da825671d6850..206e4554f8a48 100644 --- a/ext/gd/gd_ctx.c +++ b/ext/gd/gd_ctx.c @@ -57,6 +57,16 @@ static int _php_image_stream_putbuf(struct gdIOCtx *ctx, const void* buf, int l) } /* }}} */ static void _php_image_stream_ctxfree(struct gdIOCtx *ctx) /* {{{ */ +{ + if(ctx->data) { + ctx->data = NULL; + } + if(ctx) { + efree(ctx); + } +} /* }}} */ + +static void _php_image_stream_ctxfreeandclose(struct gdIOCtx *ctx) /* {{{ */ { if(ctx->data) { @@ -82,6 +92,7 @@ static void _php_image_output_ctx(INTERNAL_FUNCTION_PARAMETERS, int image_type, gdIOCtx *ctx = NULL; zval *to_zval = NULL; php_stream *stream; + int close_stream = 1; /* The third (quality) parameter for Wbmp stands for the threshold when called from image2wbmp(). * The third (quality) parameter for Wbmp and Xbm stands for the foreground color index when called @@ -120,6 +131,7 @@ static void _php_image_output_ctx(INTERNAL_FUNCTION_PARAMETERS, int image_type, if (stream == NULL) { RETURN_FALSE; } + close_stream = 0; } else if (Z_TYPE_P(to_zval) == IS_STRING) { if (CHECK_ZVAL_NULL_PATH(to_zval)) { php_error_docref(NULL, E_WARNING, "Invalid 2nd parameter, filename must not contain null bytes"); @@ -156,7 +168,11 @@ static void _php_image_output_ctx(INTERNAL_FUNCTION_PARAMETERS, int image_type, ctx = emalloc(sizeof(gdIOCtx)); ctx->putC = _php_image_stream_putc; ctx->putBuf = _php_image_stream_putbuf; - ctx->gd_free = _php_image_stream_ctxfree; + if (close_stream) { + ctx->gd_free = _php_image_stream_ctxfreeandclose; + } else { + ctx->gd_free = _php_image_stream_ctxfree; + } ctx->data = (void *)stream; } diff --git a/ext/gd/tests/bug73549.phpt b/ext/gd/tests/bug73549.phpt new file mode 100644 index 0000000000000..e0cc6cf42e572 --- /dev/null +++ b/ext/gd/tests/bug73549.phpt @@ -0,0 +1,22 @@ +--TEST-- +Bug #73549 (Use after free when stream is passed to imagepng) +--SKIPIF-- +<?php +if (!extension_loaded('gd')) die('skip gd extension not available'); +?> +--FILE-- +<?php +$stream = fopen(__DIR__ . DIRECTORY_SEPARATOR . 'bug73549.png', 'w'); +$im = imagecreatetruecolor(8, 8); +var_dump(imagepng($im, $stream)); +var_dump($stream); +?> +===DONE=== +--EXPECTF-- +bool(true) +resource(%d) of type (stream) +===DONE=== +--CLEAN-- +<?php +unlink(__DIR__ . DIRECTORY_SEPARATOR . 'bug73549.png'); +?>