Messages in this thread | | | Date | Tue, 27 Jan 2009 12:31:11 +0000 | From | Jarek Poplawski <> | Subject | Re: [PATCH v3] tcp: splice as many packets as possible at once |
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On Tue, Jan 27, 2009 at 12:16:42PM +0000, Jarek Poplawski wrote: > On Tue, Jan 27, 2009 at 10:48:05PM +1100, Herbert Xu wrote: > > On Tue, Jan 27, 2009 at 10:35:11AM +0000, Jarek Poplawski wrote: > > > > > > > > Yes, but ip_append_data() (and skb_append_datato_frags() for > > > > > NETIF_F_UFO only, so currently not a problem), uses this differently, > > > > > and these pages in sk->sk_sndmsg_page could leak or be used after > > > > > kfree. (I didn't track locking in these other places). > > > > > > > > It'll be freed when the socket is freed so that should be fine. > > > > > > I don't think so: these places can overwrite sk->sk_sndmsg_page left > > > after tcp_sendmsg(), or skb_splice_bits() now, with NULL or a new > > > pointer without put_page() (they only reference copied chunks and > > > expect auto freeing). On the other hand, if tcp_sendmsg() reads after > > > them it could use a pointer after the page is freed, I guess. > > > > I wasn't referring to the first part of your sentence. That can't > > happen because they're only used for UDP sockets, this is a TCP > > socket. > > Do you mean this part from ip_append_data() isn't used for TCP?:
Actually, the beginning part of ip_append_data() should be enough too. So I guess I missed your point...
Jarek P.
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