svn commit: r368757 - stable/12/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Fri Dec 18 10:13:28 2020
New Revision: 368757
URL: https://svnweb.freebsd.org/changeset/base/368757

Log:
  MFC r368593:
  Clean up more resouces of an existing SCTP association in case of
  a restart.
  This fixes a use-after-free scenario, which was reported by Felix
  Wilhelm from Google in case a peer is able to modify the cookie.
  However, this can also be triggered by an assciation restart under
  some specific conditions.
  
  MFC r368622:
  Harden the handling of outgoing streams in case of an restart or INIT
  collision. This avouds an out-of-bounce access in case the peer can
  break the cookie signature. Thanks to Felix Wilhelm from Google for
  reporting the issue.

Modified:
  stable/12/sys/netinet/sctp_input.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/netinet/sctp_input.c
==============================================================================
--- stable/12/sys/netinet/sctp_input.c	Fri Dec 18 10:09:21 2020	(r368756)
+++ stable/12/sys/netinet/sctp_input.c	Fri Dec 18 10:13:28 2020	(r368757)
@@ -1433,6 +1433,11 @@ sctp_process_cookie_existing(struct mbuf *m, int iphle
 	struct sctp_association *asoc;
 	struct sctp_init_chunk *init_cp, init_buf;
 	struct sctp_init_ack_chunk *initack_cp, initack_buf;
+	struct sctp_asconf_addr *aparam, *naparam;
+	struct sctp_asconf_ack *aack, *naack;
+	struct sctp_tmit_chunk *chk, *nchk;
+	struct sctp_stream_reset_list *strrst, *nstrrst;
+	struct sctp_queued_to_read *sq, *nsq;
 	struct sctp_nets *net;
 	struct mbuf *op_err;
 	struct timeval old;
@@ -1700,7 +1705,9 @@ sctp_process_cookie_existing(struct mbuf *m, int iphle
 			    NULL);
 		}
 		asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);
-		asoc->pre_open_streams = ntohs(initack_cp->init.num_outbound_streams);
+		if (asoc->pre_open_streams < asoc->streamoutcnt) {
+			asoc->pre_open_streams = asoc->streamoutcnt;
+		}
 
 		if (ntohl(init_cp->init.initiate_tag) != asoc->peer_vtag) {
 			/*
@@ -1711,7 +1718,6 @@ sctp_process_cookie_existing(struct mbuf *m, int iphle
 			 * still take a timeout to move these.. but it can't
 			 * hurt to mark them.
 			 */
-			struct sctp_tmit_chunk *chk;
 
 			TAILQ_FOREACH(chk, &stcb->asoc.sent_queue, sctp_next) {
 				if (chk->sent < SCTP_DATAGRAM_RESEND) {
@@ -1834,7 +1840,9 @@ sctp_process_cookie_existing(struct mbuf *m, int iphle
 			/* move to OPEN state, if not in SHUTDOWN_SENT */
 			SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);
 		}
-		asoc->pre_open_streams = ntohs(initack_cp->init.num_outbound_streams);
+		if (asoc->pre_open_streams < asoc->streamoutcnt) {
+			asoc->pre_open_streams = asoc->streamoutcnt;
+		}
 		asoc->init_seq_number = ntohl(initack_cp->init.initial_tsn);
 		asoc->sending_seq = asoc->asconf_seq_out = asoc->str_reset_seq_out = asoc->init_seq_number;
 		asoc->asconf_seq_out_acked = asoc->asconf_seq_out - 1;
@@ -1875,6 +1883,57 @@ sctp_process_cookie_existing(struct mbuf *m, int iphle
 			stcb->asoc.strmout[i].next_mid_unordered = 0;
 			stcb->asoc.strmout[i].last_msg_incomplete = 0;
 		}
+		TAILQ_FOREACH_SAFE(strrst, &asoc->resetHead, next_resp, nstrrst) {
+			TAILQ_REMOVE(&asoc->resetHead, strrst, next_resp);
+			SCTP_FREE(strrst, SCTP_M_STRESET);
+		}
+		TAILQ_FOREACH_SAFE(sq, &asoc->pending_reply_queue, next, nsq) {
+			TAILQ_REMOVE(&asoc->pending_reply_queue, sq, next);
+			if (sq->data) {
+				sctp_m_freem(sq->data);
+				sq->data = NULL;
+			}
+			sctp_free_remote_addr(sq->whoFrom);
+			sq->whoFrom = NULL;
+			sq->stcb = NULL;
+			sctp_free_a_readq(stcb, sq);
+		}
+		TAILQ_FOREACH_SAFE(chk, &asoc->control_send_queue, sctp_next, nchk) {
+			TAILQ_REMOVE(&asoc->control_send_queue, chk, sctp_next);
+			if (chk->data) {
+				sctp_m_freem(chk->data);
+				chk->data = NULL;
+			}
+			if (chk->holds_key_ref)
+				sctp_auth_key_release(stcb, chk->auth_keyid, SCTP_SO_LOCKED);
+			sctp_free_remote_addr(chk->whoTo);
+			SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_chunk), chk);
+			SCTP_DECR_CHK_COUNT();
+		}
+		TAILQ_FOREACH_SAFE(chk, &asoc->asconf_send_queue, sctp_next, nchk) {
+			TAILQ_REMOVE(&asoc->asconf_send_queue, chk, sctp_next);
+			if (chk->data) {
+				sctp_m_freem(chk->data);
+				chk->data = NULL;
+			}
+			if (chk->holds_key_ref)
+				sctp_auth_key_release(stcb, chk->auth_keyid, SCTP_SO_LOCKED);
+			sctp_free_remote_addr(chk->whoTo);
+			SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_chunk), chk);
+			SCTP_DECR_CHK_COUNT();
+		}
+		TAILQ_FOREACH_SAFE(aparam, &asoc->asconf_queue, next, naparam) {
+			TAILQ_REMOVE(&asoc->asconf_queue, aparam, next);
+			SCTP_FREE(aparam, SCTP_M_ASC_ADDR);
+		}
+		TAILQ_FOREACH_SAFE(aack, &asoc->asconf_ack_sent, next, naack) {
+			TAILQ_REMOVE(&asoc->asconf_ack_sent, aack, next);
+			if (aack->data != NULL) {
+				sctp_m_freem(aack->data);
+			}
+			SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_asconf_ack), aack);
+		}
+
 		/* process the INIT-ACK info (my info) */
 		asoc->my_vtag = ntohl(initack_cp->init.initiate_tag);
 		asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);
@@ -2061,7 +2120,6 @@ sctp_process_cookie_new(struct mbuf *m, int iphlen, in
 	/* process the INIT-ACK info (my info) */
 	asoc->my_vtag = ntohl(initack_cp->init.initiate_tag);
 	asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);
-	asoc->pre_open_streams = ntohs(initack_cp->init.num_outbound_streams);
 	asoc->init_seq_number = ntohl(initack_cp->init.initial_tsn);
 	asoc->sending_seq = asoc->asconf_seq_out = asoc->str_reset_seq_out = asoc->init_seq_number;
 	asoc->asconf_seq_out_acked = asoc->asconf_seq_out - 1;