[Mesa-dev] [PATCH v3 2/4] intel/decoder: Avoid freeing invalid pointer

[Lionel Landwerlin]

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

On 06/09/2018 20:37, Sagar Ghuge wrote:
> v2: Free ctx.spec if error while reading genxml (Lionel Landwerlin)
>
> v3: Handle case where genxml is empty (Lionel Landwerlin)
>
> Signed-off-by: Sagar Ghuge <sagar.ghuge at intel.com>
> ---
>   src/intel/common/gen_decoder.c | 18 +++++++++++++-----
>   1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/src/intel/common/gen_decoder.c b/src/intel/common/gen_decoder.c
> index d4db8b89cc..38a5fccb2a 100644
> --- a/src/intel/common/gen_decoder.c
> +++ b/src/intel/common/gen_decoder.c
> @@ -654,25 +654,27 @@ gen_spec_load_from_path(const struct gen_device_info *devinfo,
>      ctx.spec = gen_spec_init();
>      if (ctx.spec == NULL) {
>         fprintf(stderr, "Failed to create gen_spec\n");
> -      return NULL;
> +      goto end;
>      }
>   
>      do {
>         buf = XML_GetBuffer(ctx.parser, XML_BUFFER_SIZE);
>         len = fread(buf, 1, XML_BUFFER_SIZE, input);
> -      if (len == 0) {
> +      if (ferror(input)) {
>            fprintf(stderr, "fread: %m\n");
> -         free(ctx.spec);
> +         gen_spec_destroy(ctx.spec);
>            ctx.spec = NULL;
>            goto end;
> -      }
> +      } else if (feof(input))
> +         goto end;
> +
>         if (XML_ParseBuffer(ctx.parser, len, len == 0) == 0) {
>            fprintf(stderr,
>                    "Error parsing XML at line %ld col %ld: %s\n",
>                    XML_GetCurrentLineNumber(ctx.parser),
>                    XML_GetCurrentColumnNumber(ctx.parser),
>                    XML_ErrorString(XML_GetErrorCode(ctx.parser)));
> -         free(ctx.spec);
> +         gen_spec_destroy(ctx.spec);
>            ctx.spec = NULL;
>            goto end;
>         }
> @@ -684,6 +686,12 @@ gen_spec_load_from_path(const struct gen_device_info *devinfo,
>      fclose(input);
>      free(filename);
>   
> +   /* free ctx.spec if genxml is empty */
> +   if (ctx.spec && _mesa_hash_table_num_entries(ctx.spec->commands) == 0) {
> +      gen_spec_destroy(ctx.spec);
> +      return NULL;
> +   }
> +
>      return ctx.spec;
>   }
>