From aa78b29ebad710d743747bb9b9755b6eea9ed4d2 Mon Sep 17 00:00:00 2001 From: Eric Engestrom Date: Thu, 16 Aug 2018 15:31:55 +0100 Subject: [PATCH] egl: check for buffer overflow *before* corrupting our memory Signed-off-by: Eric Engestrom Reviewed-by: Emil Velikov --- src/egl/main/eglapi.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c index 19fae12f5b7..5e5048c4d69 100644 --- a/src/egl/main/eglapi.c +++ b/src/egl/main/eglapi.c @@ -538,19 +538,30 @@ _eglCreateExtensionsString(_EGLDisplay *dpy) static void _eglCreateAPIsString(_EGLDisplay *dpy) { +#define addstr(str) \ + { \ + const size_t old_len = strlen(dpy->ClientAPIsString); \ + const size_t add_len = sizeof(str); \ + const size_t max_len = sizeof(dpy->ClientAPIsString) - 1; \ + if (old_len + add_len <= max_len) \ + strcat(dpy->ClientAPIsString, str " "); \ + else \ + assert(!"dpy->ClientAPIsString is not large enough"); \ + } + if (dpy->ClientAPIs & EGL_OPENGL_BIT) - strcat(dpy->ClientAPIsString, "OpenGL "); + addstr("OpenGL"); if (dpy->ClientAPIs & EGL_OPENGL_ES_BIT || dpy->ClientAPIs & EGL_OPENGL_ES2_BIT || dpy->ClientAPIs & EGL_OPENGL_ES3_BIT_KHR) { - strcat(dpy->ClientAPIsString, "OpenGL_ES "); + addstr("OpenGL_ES"); } if (dpy->ClientAPIs & EGL_OPENVG_BIT) - strcat(dpy->ClientAPIsString, "OpenVG "); + addstr("OpenVG"); - assert(strlen(dpy->ClientAPIsString) < sizeof(dpy->ClientAPIsString)); +#undef addstr } static void -- 2.30.2