On 08/26/2015 04:35 PM, Xin Long wrote:
> in sctp_process_asconf(), we get address parameter from the beginning of
> the addip params. but we never check if it's really there. if the addr
> param is not there, it still can pass sctp_verify_asconf(), then to be
> handled by sctp_process_asconf(), it will not be safe.
>
> so add a code in sctp_verify_asconf() to check the address parameter is in
> the beginning, or return false to send abort.
>
> v2->v3:
> * put the check in the loop, add the check for multiple address parameters.
Please split the multiple address detection from first address detection.
They are 2 different bugs and each one deserves a separate commit and
changelog.
Thanks
-vlad
> v1->v2:
> * put the check behind the params' length verify.
>
> Signed-off-by: Xin Long <lucien....@gmail.com>
> Signed-off-by: Vlad Yasevich <vyase...@redhat.com>
> ---
> net/sctp/sm_make_chunk.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
> index 06320c8..4068fe1 100644
> --- a/net/sctp/sm_make_chunk.c
> +++ b/net/sctp/sm_make_chunk.c
> @@ -3130,14 +3130,24 @@ bool sctp_verify_asconf(const struct sctp_association
> *asoc,
> case SCTP_PARAM_ERR_CAUSE:
> break;
> case SCTP_PARAM_IPV4_ADDRESS:
> + if (addr_param_seen) {
> + /* peer placed multiple address parameters into
> + * the same asconf. reject it.
> + */
> + return false;
> + }
> if (length != sizeof(sctp_ipv4addr_param_t))
> return false;
> - addr_param_seen = true;
> + if (param.v == addip->addip_hdr.params)
> + addr_param_seen = true;
> break;
> case SCTP_PARAM_IPV6_ADDRESS:
> + if (addr_param_seen)
> + return false;
> if (length != sizeof(sctp_ipv6addr_param_t))
> return false;
> - addr_param_seen = true;
> + if (param.v == addip->addip_hdr.params)
> + addr_param_seen = true;
> break;
> case SCTP_PARAM_ADD_IP:
> case SCTP_PARAM_DEL_IP:
>
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