[ping][PATCH][BZ #18096] Handle null dereferences in wordexp

[Ondřej Bílka]

ping
On Sun, Jul 12, 2015 at 09:49:17AM +0200, Ondřej Bílka wrote:
> Hi,
> 
> Kostya, and Carlos wrote this patch on bugzilla but I didn't seen it on
> libc-alpha.
> 
> These look good for me. Carlos, could you commit it?
> 
> 
> diff --git a/posix/wordexp.c b/posix/wordexp.c
> index e711d43..d3f3764 100644
> --- a/posix/wordexp.c
> +++ b/posix/wordexp.c
> @@ -740,7 +740,7 @@ parse_arith (char **word, size_t *word_length, size_t *max_length,
>  	      ++(*offset);
>  
>  	      /* Go - evaluate. */
> -	      if (*expr && eval_expr (expr, &numresult) != 0)
> +	      if (expr && *expr && eval_expr (expr, &numresult) != 0)
>  		{
>  		  free (expr);
>  		  return WRDE_SYNTAX;
> @@ -778,7 +778,7 @@ parse_arith (char **word, size_t *word_length, size_t *max_length,
>  	      long int numresult = 0;
>  
>  	      /* Go - evaluate. */
> -	      if (*expr && eval_expr (expr, &numresult) != 0)
> +	      if (expr && *expr && eval_expr (expr, &numresult) != 0)
>  		{
>  		  free (expr);
>  		  return WRDE_SYNTAX;
> @@ -1843,11 +1843,11 @@ envsubst:
>  	  if (!colon_seen && value)
>  	    /* Substitute NULL */
>  	    ;
> -	  else
> +	  else if (flags & WRDE_SHOWERR)
>  	    {
>  	      const char *str = pattern;
>  
> -	      if (str[0] == '\0')
> +	      if (str && str[0] == '\0')
>  		str = _("parameter null or not set");
>  
>  	      __fxprintf (NULL, "%s: %s\n", env, str);