On 2019-10-21 10:23:47, Navid Emamdoost wrote: > In the implementation of aa_audit_rule_init(), when aa_label_parse() > fails the allocated memory for rule is released using > aa_audit_rule_free(). But after this release, the return statement > tries to access the label field of the rule which results in > use-after-free. Before releasing the rule, copy errNo and return it > after release. > > Fixes: 52e8c38001d8 ("apparmor: Fix memory leak of rule on error exit path")
Ugh! I'm not sure what I was thinking when I authored that patch. :/ > Signed-off-by: Navid Emamdoost <navid.emamdo...@gmail.com> > --- > Changes in v2: > -- Fix typo in description > -- move err definition inside the if statement. > > security/apparmor/audit.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c > index 5a98661a8b46..334065302fb6 100644 > --- a/security/apparmor/audit.c > +++ b/security/apparmor/audit.c > @@ -197,8 +197,9 @@ 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)) { > + int err = rule->label; Since rule->label is a pointer, I'd like to see this: int err = PTR_ERR(rule->label); > aa_audit_rule_free(rule); > - return PTR_ERR(rule->label); > + return PTR_ERR(err); This line would change to: return err; Tyler > } > > *vrule = rule; > -- > 2.17.1 >