Re: [TOMOYO #5 18/18] LSM expansion for TOMOYO Linux.

Paul Moore
2007-11-19T13:36:27Z

On Saturday 17 November 2007 11:00:20 pm Tetsuo Handa wrote:
> Hello.

Hello.

> Paul Moore wrote:
> > Okay, well if that is the case I think you are going to have another
> > problem in that you could end up throwing away skbs that haven't been
> > through your security_post_recv_datagram() hook because you _always_
> > throw away the result of the second skb_peek(). Once again, if I'm wrong
> > please correct me.
>
> I didn't understand what's wrong with throwing away the result of
> the second skb_peek().

My concern is that you stated earlier that you needed to do the second
skb_peek() because the first skb may have been removed from the socket queue
while your LSM was making an access decision in
security_post_recv_datagram(). If that is the case then the second call to
skb_peek() will return a different skb then the one you passed to
security_post_recv_datagram(). This is significant because you always throw
away this second skb without first consulting the LSM via
security_post_recv_datagram().

--
paul moore
linux security @ hp