[virglrenderer-devel] [PATCH] gallium/tgsi: fix overflow in parse property

[Marc-André Lureau]

Hi

----- Original Message -----
> In parse_identifier, it doesn't stop copying '*pcur' untill
> encounter the NULL. As the 'ret' has a fixed-size buffer, if
> the '*pcur' has a long string, there will be a buffer overflow.
> This patch avoid this.
> 
> Signed-off-by: Li Qiang <liq3ea at gmail.com>
> ---
>  src/gallium/auxiliary/tgsi/tgsi_text.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/tgsi/tgsi_text.c
> b/src/gallium/auxiliary/tgsi/tgsi_text.c
> index 1b4f594..073e6bc 100644
> --- a/src/gallium/auxiliary/tgsi/tgsi_text.c
> +++ b/src/gallium/auxiliary/tgsi/tgsi_text.c
> @@ -208,13 +208,13 @@ static boolean parse_int( const char **pcur, int *val )
>     return FALSE;
>  }
>  
> -static boolean parse_identifier( const char **pcur, char *ret )
> +static boolean parse_identifier( const char **pcur, char *ret, size_t len )
>  {
>     const char *cur = *pcur;
>     int i = 0;
>     if (is_alpha_underscore( cur )) {
>        ret[i++] = *cur++;
> -      while (is_alpha_underscore( cur ) || is_digit( cur ))
> +      while (i < len - 1 && (is_alpha_underscore( cur ) || is_digit( cur )))

I think it should return FALSE and stop parsing in this case.

>           ret[i++] = *cur++;
>        ret[i++] = '\0';
>        *pcur = cur;
> @@ -1787,7 +1787,7 @@ static boolean parse_property( struct translate_ctx
> *ctx )
>        report_error( ctx, "Syntax error" );
>        return FALSE;
>     }
> -   if (!parse_identifier( &ctx->cur, id )) {
> +   if (!parse_identifier( &ctx->cur, id, sizeof(id) )) {
>        report_error( ctx, "Syntax error" );
>        return FALSE;
>     }

btw, this patch should also be submitted to mesa-devel (copied/adapted from mesa.git/src/gallium/auxiliary/tgsi/tgsi_text.c)