1 files changed, 85 insertions, 54 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 32df65f68c12..fb3da4d8f4a3 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -156,6 +156,12 @@ static enum sctp_disposition __sctp_sf_do_9_1_abort(
 					void *arg,
 					struct sctp_cmd_seq *commands);
 
+static enum sctp_disposition
+__sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
+			   const struct sctp_association *asoc,
+			   const union sctp_subtype type, void *arg,
+			   struct sctp_cmd_seq *commands);
+
 /* Small helper function that checks if the chunk length
  * is of the appropriate length.  The 'required_length' argument
  * is set to be the size of a specific chunk we are testing.
@@ -337,6 +343,14 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
 	if (!chunk->singleton)
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
+	/* Make sure that the INIT chunk has a valid length.
+	 * Normally, this would cause an ABORT with a Protocol Violation
+	 * error, but since we don't have an association, we'll
+	 * just discard the packet.
+	 */
+	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
 	/* If the packet is an OOTB packet which is temporarily on the
 	 * control endpoint, respond with an ABORT.
 	 */
@@ -351,14 +365,6 @@ enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
 	if (chunk->sctp_hdr->vtag != 0)
 		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
 
-	/* Make sure that the INIT chunk has a valid length.
-	 * Normally, this would cause an ABORT with a Protocol Violation
-	 * error, but since we don't have an association, we'll
-	 * just discard the packet.
-	 */
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
-		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
-
 	/* If the INIT is coming toward a closing socket, we'll send back
 	 * and ABORT.  Essentially, this catches the race of INIT being
 	 * backloged to the socket at the same time as the user issues close().
@@ -704,6 +710,9 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
 	struct sock *sk;
 	int error = 0;
 
+	if (asoc && !sctp_vtag_verify(chunk, asoc))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
 	/* If the packet is an OOTB packet which is temporarily on the
 	 * control endpoint, respond with an ABORT.
 	 */
@@ -718,7 +727,8 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
 	 * in sctp_unpack_cookie().
 	 */
 	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
-		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+						  commands);
 
 	/* If the endpoint is not listening or if the number of associations
 	 * on the TCP-style socket exceed the max backlog, respond with an
@@ -1524,20 +1534,16 @@ static enum sctp_disposition sctp_sf_do_unexpected_init(
 	if (!chunk->singleton)
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
+	/* Make sure that the INIT chunk has a valid length. */
+	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
 	/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
 	 * Tag.
 	 */
 	if (chunk->sctp_hdr->vtag != 0)
 		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
 
-	/* Make sure that the INIT chunk has a valid length.
-	 * In this case, we generate a protocol violation since we have
-	 * an association established.
-	 */
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
-		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
-						  commands);
-
 	if (SCTP_INPUT_CB(chunk->skb)->encap_port != chunk->transport->encap_port)
 		return sctp_sf_new_encap_port(net, ep, asoc, type, arg, commands);
 
@@ -1882,9 +1888,9 @@ static enum sctp_disposition sctp_sf_do_dupcook_a(
 	 * its peer.
 	*/
 	if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
-		disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
-				SCTP_ST_CHUNK(chunk->chunk_hdr->type),
-				chunk, commands);
+		disposition = __sctp_sf_do_9_2_reshutack(net, ep, asoc,
+							 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
+							 chunk, commands);
 		if (SCTP_DISPOSITION_NOMEM == disposition)
 			goto nomem;
 
@@ -2202,9 +2208,11 @@ enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
 	 * enough for the chunk header.  Cookie length verification is
 	 * done later.
 	 */
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
-		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
-						  commands);
+	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) {
+		if (!sctp_vtag_verify(chunk, asoc))
+			asoc = NULL;
+		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, commands);
+	}
 
 	/* "Decode" the chunk.  We have no optional parameters so we
 	 * are in good shape.
@@ -2341,7 +2349,7 @@ enum sctp_disposition sctp_sf_shutdown_pending_abort(
 	 */
 	if (SCTP_ADDR_DEL ==
 		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
-		return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
 	if (!sctp_err_chunk_valid(chunk))
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
@@ -2387,7 +2395,7 @@ enum sctp_disposition sctp_sf_shutdown_sent_abort(
 	 */
 	if (SCTP_ADDR_DEL ==
 		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
-		return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
 	if (!sctp_err_chunk_valid(chunk))
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
@@ -2657,7 +2665,7 @@ enum sctp_disposition sctp_sf_do_9_1_abort(
 	 */
 	if (SCTP_ADDR_DEL ==
 		    sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
-		return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
 	if (!sctp_err_chunk_valid(chunk))
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
@@ -2970,13 +2978,11 @@ enum sctp_disposition sctp_sf_do_9_2_shut_ctsn(
  * that belong to this association, it should discard the INIT chunk and
  * retransmit the SHUTDOWN ACK chunk.
  */
-enum sctp_disposition sctp_sf_do_9_2_reshutack(
-					struct net *net,
-					const struct sctp_endpoint *ep,
-					const struct sctp_association *asoc,
-					const union sctp_subtype type,
-					void *arg,
-					struct sctp_cmd_seq *commands)
+static enum sctp_disposition
+__sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
+			   const struct sctp_association *asoc,
+			   const union sctp_subtype type, void *arg,
+			   struct sctp_cmd_seq *commands)
 {
 	struct sctp_chunk *chunk = arg;
 	struct sctp_chunk *reply;
@@ -3010,6 +3016,26 @@ nomem:
 	return SCTP_DISPOSITION_NOMEM;
 }
 
+enum sctp_disposition
+sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
+			 const struct sctp_association *asoc,
+			 const union sctp_subtype type, void *arg,
+			 struct sctp_cmd_seq *commands)
+{
+	struct sctp_chunk *chunk = arg;
+
+	if (!chunk->singleton)
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+	if (chunk->sctp_hdr->vtag != 0)
+		return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+
+	return __sctp_sf_do_9_2_reshutack(net, ep, asoc, type, arg, commands);
+}
+
 /*
  * sctp_sf_do_ecn_cwr
  *
@@ -3662,6 +3688,9 @@ enum sctp_disposition sctp_sf_ootb(struct net *net,
 
 	SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
 
+	if (asoc && !sctp_vtag_verify(chunk, asoc))
+		asoc = NULL;
+
 	ch = (struct sctp_chunkhdr *)chunk->chunk_hdr;
 	do {
 		/* Report violation if the chunk is less then minimal */
@@ -3777,12 +3806,6 @@ static enum sctp_disposition sctp_sf_shut_8_4_5(
 
 	SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
 
-	/* If the chunk length is invalid, we don't want to process
-	 * the reset of the packet.
-	 */
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
-		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
-
 	/* We need to discard the rest of the packet to prevent
 	 * potential boomming attacks from additional bundled chunks.
 	 * This is documented in SCTP Threats ID.
@@ -3810,6 +3833,9 @@ enum sctp_disposition sctp_sf_do_8_5_1_E_sa(struct net *net,
 {
 	struct sctp_chunk *chunk = arg;
 
+	if (!sctp_vtag_verify(chunk, asoc))
+		asoc = NULL;
+
 	/* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
 	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
 		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
@@ -3845,6 +3871,11 @@ enum sctp_disposition sctp_sf_do_asconf(struct net *net,
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 	}
 
+	/* Make sure that the ASCONF ADDIP chunk has a valid length.  */
+	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_addip_chunk)))
+		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+						  commands);
+
 	/* ADD-IP: Section 4.1.1
 	 * This chunk MUST be sent in an authenticated way by using
 	 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
@@ -3853,13 +3884,7 @@ enum sctp_disposition sctp_sf_do_asconf(struct net *net,
 	 */
 	if (!asoc->peer.asconf_capable ||
 	    (!net->sctp.addip_noauth && !chunk->auth))
-		return sctp_sf_discard_chunk(net, ep, asoc, type, arg,
-					     commands);
-
-	/* Make sure that the ASCONF ADDIP chunk has a valid length.  */
-	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_addip_chunk)))
-		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
-						  commands);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
 	hdr = (struct sctp_addiphdr *)chunk->skb->data;
 	serial = ntohl(hdr->serial);
@@ -3988,6 +4013,12 @@ enum sctp_disposition sctp_sf_do_asconf_ack(struct net *net,
 		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 	}
 
+	/* Make sure that the ADDIP chunk has a valid length.  */
+	if (!sctp_chunk_length_valid(asconf_ack,
+				     sizeof(struct sctp_addip_chunk)))
+		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+						  commands);
+
 	/* ADD-IP, Section 4.1.2:
 	 * This chunk MUST be sent in an authenticated way by using
 	 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
@@ -3996,14 +4027,7 @@ enum sctp_disposition sctp_sf_do_asconf_ack(struct net *net,
 	 */
 	if (!asoc->peer.asconf_capable ||
 	    (!net->sctp.addip_noauth && !asconf_ack->auth))
-		return sctp_sf_discard_chunk(net, ep, asoc, type, arg,
-					     commands);
-
-	/* Make sure that the ADDIP chunk has a valid length.  */
-	if (!sctp_chunk_length_valid(asconf_ack,
-				     sizeof(struct sctp_addip_chunk)))
-		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
-						  commands);
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
 
 	addip_hdr = (struct sctp_addiphdr *)asconf_ack->skb->data;
 	rcvd_serial = ntohl(addip_hdr->serial);
@@ -4575,6 +4599,9 @@ enum sctp_disposition sctp_sf_discard_chunk(struct net *net,
 {
 	struct sctp_chunk *chunk = arg;
 
+	if (asoc && !sctp_vtag_verify(chunk, asoc))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
 	/* Make sure that the chunk has a valid length.
 	 * Since we don't know the chunk type, we use a general
 	 * chunkhdr structure to make a comparison.
@@ -4642,6 +4669,9 @@ enum sctp_disposition sctp_sf_violation(struct net *net,
 {
 	struct sctp_chunk *chunk = arg;
 
+	if (!sctp_vtag_verify(chunk, asoc))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
 	/* Make sure that the chunk has a valid length. */
 	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
 		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
@@ -6348,6 +6378,7 @@ static struct sctp_packet *sctp_ootb_pkt_new(
 		 * yet.
 		 */
 		switch (chunk->chunk_hdr->type) {
+		case SCTP_CID_INIT:
 		case SCTP_CID_INIT_ACK:
 		{
 			struct sctp_initack_chunk *initack;