Re: [PATCH] apparmor: Fix use-after-free in aa_audit_rule_init

[Markus Elfring]

> … But after this release the the return statement
> tries to access the label field of the rule which results in
> use-after-free. Before releaseing the rule, copy errNo and return it
> after releasing rule.

Please avoid a duplicate word and a typo in this change description.


…
> +++ b/security/apparmor/audit.c
…
> @@ -197,8 +198,9 @@ int aa_audit_rule_init(u32 field, u32 op, char *rulestr, 
> void **vrule)
>       rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
>                                    GFP_KERNEL, true, false);
>       if (IS_ERR(rule->label)) {
> +             err = rule->label;

How do you think about to define the added local variable in this if branch 
directly?

+               int err = rule->label;

>               aa_audit_rule_free(rule);
> -             return PTR_ERR(rule->label);
> +             return PTR_ERR(err);
>       }
>
>       *vrule = rule;


Regards,
Markus