On 05/23/2017 01:28 AM, Xin Long wrote:
> After sctp changed to use transport hashtable, a transport would be
> added into global hashtable when adding the peer to an asoc, then
> the asoc can be got by searching the transport in the hashtbale.
>
> The problem is when processing dupcookie in sctp_sf_do_5_2_4_dupcook,
> a new asoc would be created. A peer with the same addr and port as
> the one in the old asoc might be added into the new asoc, but fail
> to be added into the hashtable, as they also belong to the same sk.
>
> It causes that sctp's dupcookie processing can not really work.
>
> Since the new asoc will be freed after copying it's information to
> the old asoc, it's more like a temp asoc. So this patch is to fix
> it by setting it as a temp asoc to avoid adding it's any transport
> into the hashtable and also avoid allocing assoc_id.
>
> An extra thing it has to do is to also alloc stream info for any
> temp asoc, as sctp dupcookie process needs it to update old asoc.
> But I don't think it would hurt something, as a temp asoc would
> always be freed after finishing processing cookie echo packet.
>
> Reported-by: Jianwen Ji <jiji@xxxxxxxxxx>
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Vlad Yasevich <vyasevich@xxxxxxxxx>
-vlad
> ---
> net/sctp/sm_make_chunk.c | 13 ++++---------
> net/sctp/sm_statefuns.c | 3 +++
> 2 files changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> index 8a08f13..92e332e 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -2454,16 +2454,11 @@ int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
> * stream sequence number shall be set to 0.
> */
>
> - /* Allocate storage for the negotiated streams if it is not a temporary
> - * association.
> - */
> - if (!asoc->temp) {
> - if (sctp_stream_init(asoc, gfp))
> - goto clean_up;
> + if (sctp_stream_init(asoc, gfp))
> + goto clean_up;
>
> - if (sctp_assoc_set_id(asoc, gfp))
> - goto clean_up;
> - }
> + if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
> + goto clean_up;
>
> /* ADDIP Section 4.1 ASCONF Chunk Procedures
> *
> diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
> index 4f5e6cf..f863b55 100644
> --- a/net/sctp/sm_statefuns.c
> +++ b/net/sctp/sm_statefuns.c
> @@ -2088,6 +2088,9 @@ sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
> }
> }
>
> + /* Set temp so that it won't be added into hashtable */
> + new_asoc->temp = 1;
> +
> /* Compare the tie_tag in cookie with the verification tag of
> * current association.
> */
>
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