[Mesa-dev] [PATCH] mesa: fix error handling for dlist image unpacking

[Liu Aleaxander]

On Thu, Sep 15, 2011 at 11:17 PM, Brian Paul <brian.e.paul at gmail.com> wrote:
> From: Brian Paul <brianp at vmware.com>
>
> When compiling glDrawPixels, glTexImage(), etc. and we're copying
> the user's image we need to be careful about GL error checking.
> Previously, we were incorrectly generating GL_OUT_OF_MEMORY in
> unpack_image() if width < 0 or height < 0 or for invalid format/type
> values.  We now check those arguments in unpack_image() and return NULL
> if there's a bad value.  The command will get compiled with the
> arguments as-is and image=NULL.  Later, when the command is executed the
> correct errors will ge generated.
>
> v2: also check for width or height == 0.
>
> This issue was reported by Yuanhan Liu <yuanhan.liu at linux.intel.com>

Reviewed-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>

> ---
>  src/mesa/main/dlist.c |   15 ++++++++++++++-
>  1 files changed, 14 insertions(+), 1 deletions(-)
>
> diff --git a/src/mesa/main/dlist.c b/src/mesa/main/dlist.c
> index 6e075b4..2b2ff90 100644
> --- a/src/mesa/main/dlist.c
> +++ b/src/mesa/main/dlist.c
> @@ -871,7 +871,11 @@ translate_id(GLsizei n, GLenum type, const GLvoid * list)
>
>  /**
>  * Wrapper for _mesa_unpack_image() that handles pixel buffer objects.
> - * If we run out of memory, GL_OUT_OF_MEMORY will be recorded.
> + * If width < 0 or height < 0 or format or type are invalid we'll just
> + * return NULL.  We will not generate an error since OpenGL command
> + * arguments aren't error-checked until the command is actually executed
> + * (not when they're compiled).
> + * But if we run out of memory, GL_OUT_OF_MEMORY will be recorded.
>  */
>  static GLvoid *
>  unpack_image(struct gl_context *ctx, GLuint dimensions,
> @@ -879,6 +883,15 @@ unpack_image(struct gl_context *ctx, GLuint dimensions,
>              GLenum format, GLenum type, const GLvoid * pixels,
>              const struct gl_pixelstore_attrib *unpack)
>  {
> +   if (width <= 0 || height <= 0) {
> +      return NULL;
> +   }
> +
> +   if (_mesa_bytes_per_pixel(format, type) <= 0) {
> +      /* bad format and/or type */
> +      return NULL;
> +   }
> +
>    if (!_mesa_is_bufferobj(unpack->BufferObj)) {
>       /* no PBO */
>       GLvoid *image = _mesa_unpack_image(dimensions, width, height, depth,
> --
> 1.7.3.4
>
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>



-- 
regards
Liu Aleaxander