[apparmor] [parser] fix memory leaks in variable failure cases

[Tyler Hicks]

On 2016-01-25 13:17:04, Steve Beattie wrote:
> This patch frees some leaked variables that occur when errors are
> detected while adding variables to the parser's symbol table. While not
> a significant issue currently due to the parser exiting on failures, as
> the process of library-ifying the parser continues, these need to be
> addressed. It also makes it easier to use tools like Address Sanitizer
> on the parser against our test suite.
> 
> Signed-off-by: Steve Beattie <steve at nxnw.org>

I'd prefer to see the 'autofree' used here but I'm also happy with your
patch as-is.

Acked-by: Tyler Hicks <tyhicks at canonical.com>

Tyler

> ---
>  parser/parser_yacc.y |   12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> Index: b/parser/parser_yacc.y
> ===================================================================
> --- a/parser/parser_yacc.y
> +++ b/parser/parser_yacc.y
> @@ -419,14 +419,17 @@ varassign:	TOK_SET_VAR TOK_EQUALS valuel
>  		PDEBUG("Matched: set assignment for (%s)\n", $1);
>  		err = new_set_var(var_name, list->value);
>  		if (err) {
> +			free(var_name);
>  			yyerror("variable %s was previously declared", $1);
>  			/* FIXME: it'd be handy to report the previous location */
>  		}
>  		for (list = list->next; list; list = list->next) {
>  			err = add_set_value(var_name, list->value);
> -			if (err)
> +			if (err) {
> +				free(var_name);
>  				yyerror("Error adding %s to set var %s",
>  					list->value, $1);
> +			}
>  		}
>  		free_value_list($3);
>  		free(var_name);
> @@ -445,13 +448,16 @@ varassign:	TOK_SET_VAR TOK_ADD_ASSIGN va
>  		 * failures are indicative of symtab failures */
>  		err = add_set_value(var_name, list->value);
>  		if (err) {
> +			free(var_name);
>  			yyerror("variable %s was not previously declared, but is being assigned additional values", $1);
>  		}
>  		for (list = list->next; list; list = list->next) {
>  			err = add_set_value(var_name, list->value);
> -			if (err)
> +			if (err) {
> +				free(var_name);
>  				yyerror("Error adding %s to set var %s",
>  					list->value, $1);
> +			}
>  		}
>  		free_value_list($3);
>  		free(var_name);
> @@ -469,11 +475,11 @@ varassign:	TOK_BOOL_VAR TOK_EQUALS TOK_V
>  				$1, $3);
>  		}
>  		err = add_boolean_var(var_name, boolean);
> +		free(var_name);
>  		if (err) {
>  			yyerror("variable %s was previously declared", $1);
>  			/* FIXME: it'd be handy to report the previous location */
>  		}
> -		free(var_name);
>  		free($1);
>  		free($3);
>  	}
> 
> -- 
> Steve Beattie
> <sbeattie at ubuntu.com>
> http://NxNW.org/~steve/



> -- 
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> AppArmor at lists.ubuntu.com
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