[Mesa-dev] [PATCH mesa 2/5] egl: take new string into account when checking for overflow

[Tapani Pälli]

Maybe squash this together with patch 1?

On 03/02/2017 01:31 AM, Eric Engestrom wrote:
> Otherwise the check would detect that the previous append() resulted in
> a buffer overflow, which would not even be caught if the last extension
> in the string is the one that goes over (which is likely).
>
> Signed-off-by: Eric Engestrom <eric at engestrom.ch>
> ---
>  src/egl/main/eglapi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
> index d964b4d289..220e53be8c 100644
> --- a/src/egl/main/eglapi.c
> +++ b/src/egl/main/eglapi.c
> @@ -470,7 +470,8 @@ _eglCreateExtensionsString(_EGLDisplay *dpy)
>  #define _EGL_CHECK_EXTENSION(ext)                                          \
>     do {                                                                    \
>        if (dpy->Extensions.ext) {                                           \
> -         assert(exts <= dpy->ExtensionsString + _EGL_MAX_EXTENSIONS_LEN);  \
> +         assert(exts + strlen("EGL_" #ext) <=                              \
> +                dpy->ExtensionsString + _EGL_MAX_EXTENSIONS_LEN);          \
>           _eglAppendExtension(&exts, "EGL_" #ext);                          \
>        }                                                                    \
>     } while (0)
>