[PATCH net v4] sctp: asconf's process should verify address parameter is in the beginning

[Xin Long <lucien.xin@gmail.com>]

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 detection in sctp_verify_asconf() to check the address parameter is in
the beginning, or return false to send abort.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
---
 net/sctp/sm_make_chunk.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 06320c8..f3fc881 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -3132,12 +3132,14 @@ bool sctp_verify_asconf(const struct sctp_association *asoc,
 		case SCTP_PARAM_IPV4_ADDRESS:
 			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 (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:
-- 
2.1.0