On Tue 04-04-17 16:47:11, Paul Moore wrote:
> On Mon, Apr 3, 2017 at 11:33 AM, Jan Kara <jack@xxxxxxx> wrote:
> > Currently audit code uses checking of mark->inode to verify whether mark
> > is still alive. Switch that to checking mark flags as that is more
> > logical and current way will become unreliable in future.
> >
> > Reviewed-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
> > Signed-off-by: Jan Kara <jack@xxxxxxx>
> > ---
> > kernel/audit_tree.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Should audit_tree.c:insert_hash() also be updated in a similar manner?
Do you mean the part which has become chunk_to_key()? The code there is
correct as is since we just use the value of inode pointer for hashing but
never dereference it. Also some of the callers of chunk_to_key() don't hold
locks that would prevent chunk.mark->connector->inode becoming NULL just
after we checked the FSNOTIFY_MARK_FLAG_ATTACHED flag so in practice
nothing would change. So I've decided to leave that code as is. That being
said I don't have a strong opinion about it so if you prefer checking the
flag, I can do it that way.
Honza
>
> > diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
> > index 11c7ac441624..f12bd40fb8f1 100644
> > --- a/kernel/audit_tree.c
> > +++ b/kernel/audit_tree.c
> > @@ -248,7 +248,7 @@ static void untag_chunk(struct node *p)
> >
> > mutex_lock(&entry->group->mark_mutex);
> > spin_lock(&entry->lock);
> > - if (chunk->dead || !entry->inode) {
> > + if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
> > spin_unlock(&entry->lock);
> > mutex_unlock(&entry->group->mark_mutex);
> > if (new)
> > @@ -408,7 +408,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
> >
> > mutex_lock(&old_entry->group->mark_mutex);
> > spin_lock(&old_entry->lock);
> > - if (!old_entry->inode) {
> > + if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
> > /* old_entry is being shot, lets just lie */
> > spin_unlock(&old_entry->lock);
> > mutex_unlock(&old_entry->group->mark_mutex);
> > --
> > 2.10.2
> >
>
> --
> paul moore
> www.paul-moore.com
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
