Merge branch 'sctp'

Daniel Borkmann says:

====================
Here are some SCTP fixes.

[ Note, immediate workaround would be to disable ASCONF (it
  is sysctl disabled by default). It is actually only used
  together with chunk authentication. ]
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/sctp/sctp.h

@@ -426,6 +426,11 @@ static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_associat
 	asoc->pmtu_pending = 0;
 }
 
+static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
+{
+	return !list_empty(&chunk->list);
+}
+
 /* Walk through a list of TLV parameters.  Don't trust the
  * individual parameter lengths and instead depend on
  * the chunk length to indicate when to stop.  Make sure

include/net/sctp/sm.h

@@ -248,9 +248,9 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
 					      int, __be16);
 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
 					     union sctp_addr *addr);
-int sctp_verify_asconf(const struct sctp_association *asoc,
-		       struct sctp_paramhdr *param_hdr, void *chunk_end,
-		       struct sctp_paramhdr **errp);
+bool sctp_verify_asconf(const struct sctp_association *asoc,
+			struct sctp_chunk *chunk, bool addr_param_needed,
+			struct sctp_paramhdr **errp);
 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 				       struct sctp_chunk *asconf);
 int sctp_process_asconf_ack(struct sctp_association *asoc,

net/sctp/associola.c

@@ -1668,6 +1668,8 @@ struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
 	 * ack chunk whose serial number matches that of the request.
 	 */
 	list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
+		if (sctp_chunk_pending(ack))
+			continue;
 		if (ack->subh.addip_hdr->serial == serial) {
 			sctp_chunk_hold(ack);
 			return ack;

net/sctp/inqueue.c

@@ -140,18 +140,9 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
 		} else {
 			/* Nothing to do. Next chunk in the packet, please. */
 			ch = (sctp_chunkhdr_t *) chunk->chunk_end;
-
 			/* Force chunk->skb->data to chunk->chunk_end.  */
-			skb_pull(chunk->skb,
-				 chunk->chunk_end - chunk->skb->data);
-
-			/* Verify that we have at least chunk headers
-			 * worth of buffer left.
-			 */
-			if (skb_headlen(chunk->skb) < sizeof(sctp_chunkhdr_t)) {
-				sctp_chunk_free(chunk);
-				chunk = queue->in_progress = NULL;
-			}
+			skb_pull(chunk->skb, chunk->chunk_end - chunk->skb->data);
+			/* We are guaranteed to pull a SCTP header. */
 		}
 	}
 
@@ -187,24 +178,14 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
 	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
 	chunk->subh.v = NULL; /* Subheader is no longer valid.  */
 
-	if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) {
+	if (chunk->chunk_end + sizeof(sctp_chunkhdr_t) <
+	    skb_tail_pointer(chunk->skb)) {
 		/* This is not a singleton */
 		chunk->singleton = 0;
 	} else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
-		/* RFC 2960, Section 6.10  Bundling
-		 *
-		 * Partial chunks MUST NOT be placed in an SCTP packet.
-		 * If the receiver detects a partial chunk, it MUST drop
-		 * the chunk.
-		 *
-		 * Since the end of the chunk is past the end of our buffer
-		 * (which contains the whole packet, we can freely discard
-		 * the whole packet.
-		 */
-		sctp_chunk_free(chunk);
-		chunk = queue->in_progress = NULL;
-
-		return NULL;
+		/* Discard inside state machine. */
+		chunk->pdiscard = 1;
+		chunk->chunk_end = skb_tail_pointer(chunk->skb);
 	} else {
 		/* We are at the end of the packet, so mark the chunk
 		 * in case we need to send a SACK.

net/sctp/sm_make_chunk.c

@@ -3110,50 +3110,63 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
 	return SCTP_ERROR_NO_ERROR;
 }
 
-/* Verify the ASCONF packet before we process it.  */
-int sctp_verify_asconf(const struct sctp_association *asoc,
-		       struct sctp_paramhdr *param_hdr, void *chunk_end,
-		       struct sctp_paramhdr **errp) {
-	sctp_addip_param_t *asconf_param;
+/* Verify the ASCONF packet before we process it. */
+bool sctp_verify_asconf(const struct sctp_association *asoc,
+			struct sctp_chunk *chunk, bool addr_param_needed,
+			struct sctp_paramhdr **errp)
+{
+	sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
 	union sctp_params param;
-	int length, plen;
-
-	param.v = (sctp_paramhdr_t *) param_hdr;
-	while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
-		length = ntohs(param.p->length);
-		*errp = param.p;
+	bool addr_param_seen = false;
 
-		if (param.v > chunk_end - length ||
-		    length < sizeof(sctp_paramhdr_t))
-			return 0;
+	sctp_walk_params(param, addip, addip_hdr.params) {
+		size_t length = ntohs(param.p->length);
 
+		*errp = param.p;
 		switch (param.p->type) {
+		case SCTP_PARAM_ERR_CAUSE:
+			break;
+		case SCTP_PARAM_IPV4_ADDRESS:
+			if (length != sizeof(sctp_ipv4addr_param_t))
+				return false;
+			addr_param_seen = true;
+			break;
+		case SCTP_PARAM_IPV6_ADDRESS:
+			if (length != sizeof(sctp_ipv6addr_param_t))
+				return false;
+			addr_param_seen = true;
+			break;
 		case SCTP_PARAM_ADD_IP:
 		case SCTP_PARAM_DEL_IP:
 		case SCTP_PARAM_SET_PRIMARY:
-			asconf_param = (sctp_addip_param_t *)param.v;
-			plen = ntohs(asconf_param->param_hdr.length);
-			if (plen < sizeof(sctp_addip_param_t) +
-			    sizeof(sctp_paramhdr_t))
-				return 0;
+			/* In ASCONF chunks, these need to be first. */
+			if (addr_param_needed && !addr_param_seen)
+				return false;
+			length = ntohs(param.addip->param_hdr.length);
+			if (length < sizeof(sctp_addip_param_t) +
+				     sizeof(sctp_paramhdr_t))
+				return false;
 			break;
 		case SCTP_PARAM_SUCCESS_REPORT:
 		case SCTP_PARAM_ADAPTATION_LAYER_IND:
 			if (length != sizeof(sctp_addip_param_t))
-				return 0;
-
+				return false;
 			break;
 		default:
-			break;
+			/* This is unkown to us, reject! */
+			return false;
 		}
-
-		param.v += WORD_ROUND(length);
 	}
 
-	if (param.v != chunk_end)
-		return 0;
+	/* Remaining sanity checks. */
+	if (addr_param_needed && !addr_param_seen)
+		return false;
+	if (!addr_param_needed && addr_param_seen)
+		return false;
+	if (param.v != chunk->chunk_end)
+		return false;
 
-	return 1;
+	return true;
 }
 
 /* Process an incoming ASCONF chunk with the next expected serial no. and
@@ -3162,16 +3175,17 @@ int sctp_verify_asconf(const struct sctp_association *asoc,
 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 				       struct sctp_chunk *asconf)
 {
+	sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
+	bool all_param_pass = true;
+	union sctp_params param;
 	sctp_addiphdr_t		*hdr;
 	union sctp_addr_param	*addr_param;
 	sctp_addip_param_t	*asconf_param;
 	struct sctp_chunk	*asconf_ack;
-
 	__be16	err_code;
 	int	length = 0;
 	int	chunk_len;
 	__u32	serial;
-	int	all_param_pass = 1;
 
 	chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
 	hdr = (sctp_addiphdr_t *)asconf->skb->data;
@@ -3199,9 +3213,14 @@ struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 		goto done;
 
 	/* Process the TLVs contained within the ASCONF chunk. */
-	while (chunk_len > 0) {
+	sctp_walk_params(param, addip, addip_hdr.params) {
+		/* Skip preceeding address parameters. */
+		if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
+		    param.p->type == SCTP_PARAM_IPV6_ADDRESS)
+			continue;
+
 		err_code = sctp_process_asconf_param(asoc, asconf,
-						     asconf_param);
+						     param.addip);
 		/* ADDIP 4.1 A7)
 		 * If an error response is received for a TLV parameter,
 		 * all TLVs with no response before the failed TLV are
@@ -3209,28 +3228,20 @@ struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 		 * the failed response are considered unsuccessful unless
 		 * a specific success indication is present for the parameter.
 		 */
-		if (SCTP_ERROR_NO_ERROR != err_code)
-			all_param_pass = 0;
-
+		if (err_code != SCTP_ERROR_NO_ERROR)
+			all_param_pass = false;
 		if (!all_param_pass)
-			sctp_add_asconf_response(asconf_ack,
-						 asconf_param->crr_id, err_code,
-						 asconf_param);
+			sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
+						 err_code, param.addip);
 
 		/* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
 		 * an IP address sends an 'Out of Resource' in its response, it
 		 * MUST also fail any subsequent add or delete requests bundled
 		 * in the ASCONF.
 		 */
-		if (SCTP_ERROR_RSRC_LOW == err_code)
+		if (err_code == SCTP_ERROR_RSRC_LOW)
 			goto done;
-
-		/* Move to the next ASCONF param. */
-		length = ntohs(asconf_param->param_hdr.length);
-		asconf_param = (void *)asconf_param + length;
-		chunk_len -= length;
 	}
-
 done:
 	asoc->peer.addip_serial++;
 

net/sctp/sm_statefuns.c

@@ -170,6 +170,9 @@ sctp_chunk_length_valid(struct sctp_chunk *chunk,
 {
 	__u16 chunk_length = ntohs(chunk->chunk_hdr->length);
 
+	/* Previously already marked? */
+	if (unlikely(chunk->pdiscard))
+		return 0;
 	if (unlikely(chunk_length < required_length))
 		return 0;
 
@@ -3591,9 +3594,7 @@ sctp_disposition_t sctp_sf_do_asconf(struct net *net,
 	struct sctp_chunk	*asconf_ack = NULL;
 	struct sctp_paramhdr	*err_param = NULL;
 	sctp_addiphdr_t		*hdr;
-	union sctp_addr_param	*addr_param;
 	__u32			serial;
-	int			length;
 
 	if (!sctp_vtag_verify(chunk, asoc)) {
 		sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
@@ -3618,17 +3619,8 @@ sctp_disposition_t sctp_sf_do_asconf(struct net *net,
 	hdr = (sctp_addiphdr_t *)chunk->skb->data;
 	serial = ntohl(hdr->serial);
 
-	addr_param = (union sctp_addr_param *)hdr->params;
-	length = ntohs(addr_param->p.length);
-	if (length < sizeof(sctp_paramhdr_t))
-		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
-			   (void *)addr_param, commands);
-
 	/* Verify the ASCONF chunk before processing it. */
-	if (!sctp_verify_asconf(asoc,
-			    (sctp_paramhdr_t *)((void *)addr_param + length),
-			    (void *)chunk->chunk_end,
-			    &err_param))
+	if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
 		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
 						  (void *)err_param, commands);
 
@@ -3745,10 +3737,7 @@ sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
 	rcvd_serial = ntohl(addip_hdr->serial);
 
 	/* Verify the ASCONF-ACK chunk before processing it. */
-	if (!sctp_verify_asconf(asoc,
-	    (sctp_paramhdr_t *)addip_hdr->params,
-	    (void *)asconf_ack->chunk_end,
-	    &err_param))
+	if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
 		return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
 			   (void *)err_param, commands);