On Thu, Apr 18, 2019 at 4:52 PM Paul Moore <[email protected]> wrote: > > On Thu, Apr 18, 2019 at 1:39 PM Wenwen Wang <[email protected]> wrote: > > In audit_rule_change(), audit_data_to_entry() is firstly invoked to > > translate the payload data to the kernel's rule representation. In > > audit_data_to_entry(), depending on the audit field type, an audit tree may > > be created in audit_make_tree(), which eventually invokes kmalloc() to > > allocate the tree. Since this tree is a temporary tree, it will be then > > freed in the following execution, e.g., audit_add_rule() if the message > > type is AUDIT_ADD_RULE or audit_del_rule() if the message type is > > AUDIT_DEL_RULE. However, if the message type is neither AUDIT_ADD_RULE nor > > AUDIT_DEL_RULE, i.e., the default case of the switch statement, this > > temporary tree is not freed. > > > > To fix this issue, free the allocated tree in the default case. > > > > Signed-off-by: Wenwen Wang <[email protected]> > > --- > > kernel/auditfilter.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c > > index 63f8b3f..70a34db 100644 > > --- a/kernel/auditfilter.c > > +++ b/kernel/auditfilter.c > > @@ -1128,6 +1128,8 @@ int audit_rule_change(int type, int seq, void *data, > > size_t datasz) > > audit_log_rule_change("remove_rule", &entry->rule, !err); > > break; > > default: > > + if (entry->rule.tree) > > + audit_put_tree(entry->rule.tree); > > err = -EINVAL; > > WARN_ON(1); > > } > > Since there are only two "types" (_ADD_RULE and _DEL_RULE) and the > allocation is only three lines (audit_data_to_entry() + two lines for > error handling), maybe it makes more sense to duplicate the > audit_data_to_entry() call into the individual case statements so we > are only doing the allocations when we have a valid "type"? > This sounds reasonable to me. I will rework the patch. Thanks!
Wenwen -- Linux-audit mailing list [email protected] https://www.redhat.com/mailman/listinfo/linux-audit
