Re: [PATCH] kernel/auditfilter.c: need process 'tree' when audit_add_watch() failed in audit_add_rule().

[Chen Gang <gang.chen@asianux.com>]

On 05/23/2013 05:18 AM, Andrew Morton wrote:
> On Fri, 10 May 2013 18:12:26 +0800 Chen Gang <gang.chen@asianux.com> wrote:
> 
>> > 
>> > If both 'tree' and 'watch' are valid, need call audit_put_tree(), just
>> > like the upper area has done within function audit_add_rule().
>> > 
>> > Signed-off-by: Chen Gang <gang.chen@asianux.com>
>> > ---
>> >  kernel/auditfilter.c |    6 ++++++
>> >  1 files changed, 6 insertions(+), 0 deletions(-)
>> > 
>> > diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
>> > index f9fc54b..81f63f9 100644
>> > --- a/kernel/auditfilter.c
>> > +++ b/kernel/auditfilter.c
>> > @@ -952,6 +952,12 @@ static inline int audit_add_rule(struct audit_entry *entry)
>> >  		err = audit_add_watch(&entry->rule, &list);
>> >  		if (err) {
>> >  			mutex_unlock(&audit_filter_mutex);
>> > +			/*
>> > +			 * normally audit_add_tree_rule() will free it
>> > +			 * on failure
>> > +			 */
>> > +			if (tree)
>> > +				audit_put_tree(tree);
>> >  			goto error;
>> >  		}
>> >  	}
> Are you sure?  Or is the earlier audit_put_tree(tree) wrong?
> 

Yes I am sure.

Since audit_add_tree_rule() will really free it on failure, we have to
be sure to free it in another area within audit_add_rule().


> Where is the "get" which this "put" is undoing?
> 
> 

"Allocating tree" is the "get", this "put" will really free the tree.



Thanks.
-- 
Chen Gang

Asianux Corporation