From 42e8890c91c044d7334ddcc13c3ef96fb6a79341 Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Wed, 18 Mar 2020 19:54:13 +0100 Subject: [PATCH] (GL) Fix NULL pointer dereference in gl2_init() Commit 10df615d141 ("add "Send Debug Info" option under Help") added some debug information that contains the GL_VENDOR, GL_RENDERER and GL_VERSION strings that are returned by the glGetString() function, and is used by algorithms to recognize the platform. But in some GL contexts, these may be NULL which leads to a NULL pointer dereference when trying to copy the returned strings. Commit 97247dbaecc ("gl1: check for vender/renderer was in the wrong place") later fixed it for the GL1 driver, but it missed doing the same for the GL driver. For example, on an Exynos Odroid XU4 with a mali-fdev GL context I get: $ retroarch -v [INFO] RetroArch 1.8.5 (Git 8d3f25f) [INFO] === Build ======================================= [INFO] Capabilities: NEON VFPv3 VFPv4 [INFO] Built: Mar 18 2020 [INFO] Version: 1.8.5 [INFO] Git: 8d3f25f [INFO] ================================================= [INFO] [Environ]: SET_PIXEL_FORMAT: RGB565. [INFO] Version of libretro API: 1 [INFO] Compiled against API: 1 [INFO] [Audio]: Set audio input rate to: 30000.00 Hz. [INFO] [Video]: Video @ 960x720 [INFO] [EGL] Falling back to eglGetDisplay [INFO] [EGL]: EGL version: 1.4 [INFO] [GL]: Found GL context: mali-fbdev [INFO] [GL]: Detecting screen resolution 0x0. [INFO] [EGL]: Current context: 0xf08e20. [INFO] [GL]: Vendor: (null), Renderer: (null). [INFO] [GL]: Version: (null). Segmentation fault (core dumped) --- gfx/drivers/gl.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/gfx/drivers/gl.c b/gfx/drivers/gl.c index 2837ecd6cc..6abbfef78e 100644 --- a/gfx/drivers/gl.c +++ b/gfx/drivers/gl.c @@ -3671,12 +3671,19 @@ static void *gl2_init(const video_info_t *video, device_str[0] = '\0'; - strlcpy(device_str, vendor, sizeof(device_str)); - strlcat(device_str, " ", sizeof(device_str)); - strlcat(device_str, renderer, sizeof(device_str)); + if (!string_is_empty(vendor)) + { + strlcpy(device_str, vendor, sizeof(device_str)); + strlcat(device_str, " ", sizeof(device_str)); + } + + if (!string_is_empty(renderer)) + strlcat(device_str, renderer, sizeof(device_str)); video_driver_set_gpu_device_string(device_str); - video_driver_set_gpu_api_version_string(version); + + if (!string_is_empty(version)) + video_driver_set_gpu_api_version_string(version); } #ifdef _WIN32