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.

>  
>       /* 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;
+       }
+
        if (sctp_state(asoc, ESTABLISHED) ||
            sctp_state(asoc, CLOSED) ||
            sctp_state(asoc, SHUTDOWN_RECEIVED)) {

Also untested, just sharing the idea.

  Marcelo

Reply via email to