diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index ca1db89..0993b49 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -359,6 +359,12 @@ static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
 	 typecheck(__u32, b) && \
 	 ((__s32)((a) - (b)) <= 0))
 
+/* Compare two MIDs */
+#define MID_lt(a, b)	\
+	(typecheck(__u32, a) && \
+	 typecheck(__u32, b) && \
+	 ((__s32)((a) - (b)) < 0))
+
 /* Compare two SSNs */
 #define SSN_lt(a,b)		\
 	(typecheck(__u16, a) && \
diff --git a/include/net/sctp/stream_interleave.h b/include/net/sctp/stream_interleave.h
index 99f399e..d8d1b51 100644
--- a/include/net/sctp/stream_interleave.h
+++ b/include/net/sctp/stream_interleave.h
@@ -38,6 +38,7 @@ struct sctp_stream_interleave {
 					    const struct sctp_sndrcvinfo *sinfo,
 					    int len, __u8 flags, gfp_t gfp);
 	void	(*assign_number)(struct sctp_chunk *chunk);
+	bool	(*validate_data)(struct sctp_chunk *chunk);
 };
 
 void sctp_stream_interleave_init(struct sctp_stream *stream);
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index bd2249d..348b25e 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1381,7 +1381,11 @@ struct sctp_stream_out {
 };
 
 struct sctp_stream_in {
-	__u16	ssn;
+	union {
+		__u32 mid;
+		__u16 ssn;
+	};
+	__u32 fsn;
 };
 
 struct sctp_stream {
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 8f8ccde..c609c54 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -3013,7 +3013,7 @@ enum sctp_disposition sctp_sf_eat_data_6_2(struct net *net,
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 	}
 
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_data_chunk)))
+	if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
 		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
 						  commands);
 
@@ -3034,7 +3034,7 @@ enum sctp_disposition sctp_sf_eat_data_6_2(struct net *net,
 	case SCTP_IERROR_PROTO_VIOLATION:
 		return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
 					       (u8 *)chunk->subh.data_hdr,
-					       sizeof(struct sctp_datahdr));
+					       sctp_datahdr_len(&asoc->stream));
 	default:
 		BUG();
 	}
@@ -3133,7 +3133,7 @@ enum sctp_disposition sctp_sf_eat_data_fast_4_4(
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 	}
 
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_data_chunk)))
+	if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
 		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
 						  commands);
 
@@ -3150,7 +3150,7 @@ enum sctp_disposition sctp_sf_eat_data_fast_4_4(
 	case SCTP_IERROR_PROTO_VIOLATION:
 		return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
 					       (u8 *)chunk->subh.data_hdr,
-					       sizeof(struct sctp_datahdr));
+					       sctp_datahdr_len(&asoc->stream));
 	default:
 		BUG();
 	}
@@ -6244,14 +6244,12 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 	struct sctp_chunk *err;
 	enum sctp_verb deliver;
 	size_t datalen;
-	u8 ordered = 0;
-	u16 ssn, sid;
 	__u32 tsn;
 	int tmp;
 
 	data_hdr = (struct sctp_datahdr *)chunk->skb->data;
 	chunk->subh.data_hdr = data_hdr;
-	skb_pull(chunk->skb, sizeof(*data_hdr));
+	skb_pull(chunk->skb, sctp_datahdr_len(&asoc->stream));
 
 	tsn = ntohl(data_hdr->tsn);
 	pr_debug("%s: TSN 0x%x\n", __func__, tsn);
@@ -6299,7 +6297,7 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 	 * Actually, allow a little bit of overflow (up to a MTU).
 	 */
 	datalen = ntohs(chunk->chunk_hdr->length);
-	datalen -= sizeof(struct sctp_data_chunk);
+	datalen -= sctp_datachk_len(&asoc->stream);
 
 	deliver = SCTP_CMD_CHUNK_ULP;
 
@@ -6394,7 +6392,6 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 		SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
 		if (chunk->asoc)
 			chunk->asoc->stats.iodchunks++;
-		ordered = 1;
 	}
 
 	/* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
@@ -6405,8 +6402,7 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 	 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
 	 * and discard the DATA chunk.
 	 */
-	sid = ntohs(data_hdr->stream);
-	if (sid >= asoc->stream.incnt) {
+	if (ntohs(data_hdr->stream) >= asoc->stream.incnt) {
 		/* Mark tsn as received even though we drop it */
 		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
 
@@ -6427,8 +6423,7 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 	 * SSN is smaller then the next expected one.  If it is, it wrapped
 	 * and is invalid.
 	 */
-	ssn = ntohs(data_hdr->ssn);
-	if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->stream, in, sid)))
+	if (!asoc->stream.si->validate_data(chunk))
 		return SCTP_IERROR_PROTO_VIOLATION;
 
 	/* Send the data up to the user.  Note:  Schedule  the
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index 79b6bee..8c9bb41 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -985,6 +985,9 @@ static const struct sctp_sm_table_entry *sctp_chunk_event_lookup(
 	if (state > SCTP_STATE_MAX)
 		return &bug;
 
+	if (net->sctp.intl_enable && cid == SCTP_CID_I_DATA)
+		cid = SCTP_CID_DATA;
+
 	if (cid <= SCTP_CID_BASE_MAX)
 		return &chunk_event_table[cid][state];
 
diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c
index 3ac47e7..3d8733b 100644
--- a/net/sctp/stream_interleave.c
+++ b/net/sctp/stream_interleave.c
@@ -92,11 +92,49 @@ static void sctp_chunk_assign_mid(struct sctp_chunk *chunk)
 	}
 }
 
+static bool sctp_validate_data(struct sctp_chunk *chunk)
+{
+	const struct sctp_stream *stream;
+	__u16 sid, ssn;
+
+	if (chunk->chunk_hdr->type != SCTP_CID_DATA)
+		return false;
+
+	if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
+		return true;
+
+	stream = &chunk->asoc->stream;
+	sid = sctp_chunk_stream_no(chunk);
+	ssn = ntohs(chunk->subh.data_hdr->ssn);
+
+	return !SSN_lt(ssn, sctp_ssn_peek(stream, in, sid));
+}
+
+static bool sctp_validate_idata(struct sctp_chunk *chunk)
+{
+	struct sctp_stream *stream;
+	__u32 mid;
+	__u16 sid;
+
+	if (chunk->chunk_hdr->type != SCTP_CID_I_DATA)
+		return false;
+
+	if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
+		return true;
+
+	stream = &chunk->asoc->stream;
+	sid = sctp_chunk_stream_no(chunk);
+	mid = ntohl(chunk->subh.idata_hdr->mid);
+
+	return !MID_lt(mid, sctp_mid_peek(stream, in, sid));
+}
+
 static struct sctp_stream_interleave sctp_stream_interleave_0 = {
 	.data_chunk_len		= sizeof(struct sctp_data_chunk),
 	/* DATA process functions */
 	.make_datafrag		= sctp_make_datafrag_empty,
 	.assign_number		= sctp_chunk_assign_ssn,
+	.validate_data		= sctp_validate_data,
 };
 
 static struct sctp_stream_interleave sctp_stream_interleave_1 = {
@@ -104,6 +142,7 @@ static struct sctp_stream_interleave sctp_stream_interleave_1 = {
 	/* I-DATA process functions */
 	.make_datafrag		= sctp_make_idatafrag_empty,
 	.assign_number		= sctp_chunk_assign_mid,
+	.validate_data		= sctp_validate_idata,
 };
 
 void sctp_stream_interleave_init(struct sctp_stream *stream)
