On Thu, May 30, 2019 at 12:17:05PM -0300, Marcelo Ricardo Leitner wrote:
> On Thu, May 30, 2019 at 10:20:11AM -0400, Neil Horman wrote:
> > On Wed, May 29, 2019 at 08:37:57PM -0300, Marcelo Ricardo Leitner wrote:
> > > On Wed, May 29, 2019 at 03:07:09PM -0400, Neil Horman wrote:
> > > > --- a/net/sctp/sm_make_chunk.c
> > > > +++ b/net/sctp/sm_make_chunk.c
> > > > @@ -2419,9 +2419,12 @@ int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
> > > > /* Copy cookie in case we need to resend COOKIE-ECHO. */
> > > > cookie = asoc->peer.cookie;
> > > > if (cookie) {
> > > > + if (asoc->peer.cookie_allocated)
> > > > + kfree(cookie);
> > > > asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
> > > > if (!asoc->peer.cookie)
> > > > goto clean_up;
> > > > + asoc->peer.cookie_allocated=1;
> > > > }
> > > >
> > > > /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
> > >
> > > What if we kmemdup directly at sctp_process_param(), as it's done for
> > > others already? Like SCTP_PARAM_RANDOM and SCTP_PARAM_HMAC_ALGO. I
> > > don't see a reason for SCTP_PARAM_STATE_COOKIE to be different
> > > here. This way it would be always allocated, and ready to be kfreed.
> > >
> > > We still need to free it after the handshake, btw.
> > >
> > > Marcelo
> > >
> >
> > Still untested, but something like this?
> >
>
> Yes, just..
>
> >
> > diff --git a/net/sctp/associola.c b/net/sctp/associola.c
> > index d2c7d0d2abc1..718b9917844e 100644
> > --- a/net/sctp/associola.c
> > +++ b/net/sctp/associola.c
> > @@ -393,6 +393,7 @@ void sctp_association_free(struct sctp_association *asoc)
> > kfree(asoc->peer.peer_random);
> > kfree(asoc->peer.peer_chunks);
> > kfree(asoc->peer.peer_hmacs);
> > + kfree(asoc->peer.cookie);
>
> this chunk is not needed because it is freed right above the first
> kfree() in the context here.
>
Ah, thanks, missed that.
> >
> > /* Release the transport structures. */
> > list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
> > diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> > index 72e74503f9fc..ff365f22a3c1 100644
> > --- a/net/sctp/sm_make_chunk.c
> > +++ b/net/sctp/sm_make_chunk.c
> > @@ -2431,14 +2431,6 @@ int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
> > /* Peer Rwnd : Current calculated value of the peer's rwnd. */
> > asoc->peer.rwnd = asoc->peer.i.a_rwnd;
> >
> > - /* Copy cookie in case we need to resend COOKIE-ECHO. */
> > - cookie = asoc->peer.cookie;
> > - if (cookie) {
> > - asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
> > - if (!asoc->peer.cookie)
> > - goto clean_up;
> > - }
> > -
> > /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
> > * high (for example, implementations MAY use the size of the receiver
> > * advertised window).
> > @@ -2607,7 +2599,9 @@ static int sctp_process_param(struct sctp_association *asoc,
> > case SCTP_PARAM_STATE_COOKIE:
> > asoc->peer.cookie_len =
> > ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
> > - asoc->peer.cookie = param.cookie->body;
> > + asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
> > + if (!asoc->peer.cookie)
> > + retval = 0;
> > break;
> >
> > case SCTP_PARAM_HEARTBEAT_INFO:
>
> Plus:
>
> --- a/net/sctp/sm_sideeffect.c
> +++ b/net/sctp/sm_sideeffect.c
> @@ -898,6 +898,11 @@ static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
> asoc->rto_initial;
> }
>
> + if (sctp_state(asoc, ESTABLISHED)) {
> + kfree(asoc->peer.cookie);
> + asoc->peer.cookie = NULL;
> + }
> +
Not sure I follow why this is needed. It doesn't hurt anything of course, but
if we're freeing in sctp_association_free, we don't need to duplicate the
operation here, do we?
> if (sctp_state(asoc, ESTABLISHED) ||
> sctp_state(asoc, CLOSED) ||
> sctp_state(asoc, SHUTDOWN_RECEIVED)) {
>
> Also untested, just sharing the idea.
>
> Marcelo
>
