sctp: handle errors when updating asoc

It's a bad thing not to handle errors when updating asoc. The memory
allocation failure in any of the functions called in sctp_assoc_update()
would cause sctp to work unexpectedly.

This patch is to fix it by aborting the asoc and reporting the error when
any of these functions fails.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 5051317..e26763b 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1953,8 +1953,8 @@ struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
                                           const union sctp_addr *,
                                           const union sctp_addr *);
 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
-void sctp_assoc_update(struct sctp_association *old,
-                      struct sctp_association *new);
+int sctp_assoc_update(struct sctp_association *old,
+                     struct sctp_association *new);
 
 __u32 sctp_association_get_next_tsn(struct sctp_association *);
 

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 72b07dd..757be41 100644 (file)
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1112,8 +1112,8 @@ void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
 }
 
 /* Update an association (possibly from unexpected COOKIE-ECHO processing).  */
-void sctp_assoc_update(struct sctp_association *asoc,
-                      struct sctp_association *new)
+int sctp_assoc_update(struct sctp_association *asoc,
+                     struct sctp_association *new)
 {
        struct sctp_transport *trans;
        struct list_head *pos, *temp;
@@ -1124,8 +1124,10 @@ void sctp_assoc_update(struct sctp_association *asoc,
        asoc->peer.sack_needed = new->peer.sack_needed;
        asoc->peer.auth_capable = new->peer.auth_capable;
        asoc->peer.i = new->peer.i;
-       sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
-                        asoc->peer.i.initial_tsn, GFP_ATOMIC);
+
+       if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
+                             asoc->peer.i.initial_tsn, GFP_ATOMIC))
+               return -ENOMEM;
 
        /* Remove any peer addresses not present in the new association. */
        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
@@ -1169,11 +1171,11 @@ void sctp_assoc_update(struct sctp_association *asoc,
        } else {
                /* Add any peer addresses from the new association. */
                list_for_each_entry(trans, &new->peer.transport_addr_list,
-                               transports) {
-                       if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
-                               sctp_assoc_add_peer(asoc, &trans->ipaddr,
-                                                   GFP_ATOMIC, trans->state);
-               }
+                                   transports)
+                       if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr) &&
+                           !sctp_assoc_add_peer(asoc, &trans->ipaddr,
+                                                GFP_ATOMIC, trans->state))
+                               return -ENOMEM;
 
                asoc->ctsn_ack_point = asoc->next_tsn - 1;
                asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
@@ -1182,7 +1184,8 @@ void sctp_assoc_update(struct sctp_association *asoc,
                        sctp_stream_update(&asoc->stream, &new->stream);
 
                /* get a new assoc id if we don't have one yet. */
-               sctp_assoc_set_id(asoc, GFP_ATOMIC);
+               if (sctp_assoc_set_id(asoc, GFP_ATOMIC))
+                       return -ENOMEM;
        }
 
        /* SCTP-AUTH: Save the peer parameters from the new associations
@@ -1200,7 +1203,7 @@ void sctp_assoc_update(struct sctp_association *asoc,
        asoc->peer.peer_hmacs = new->peer.peer_hmacs;
        new->peer.peer_hmacs = NULL;
 
-       sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
+       return sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
 }
 
 /* Update the retran path for sending a retransmitted packet.

diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index 7623566..dfe1fcb 100644 (file)
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -818,6 +818,28 @@ static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
        asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 }
 
+static void sctp_cmd_assoc_update(sctp_cmd_seq_t *cmds,
+                                 struct sctp_association *asoc,
+                                 struct sctp_association *new)
+{
+       struct net *net = sock_net(asoc->base.sk);
+       struct sctp_chunk *abort;
+
+       if (!sctp_assoc_update(asoc, new))
+               return;
+
+       abort = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t));
+       if (abort) {
+               sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
+               sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+       }
+       sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
+       sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
+                       SCTP_PERR(SCTP_ERROR_RSRC_LOW));
+       SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+       SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+}
+
 /* Helper function to change the state of an association. */
 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
                               struct sctp_association *asoc,
@@ -1294,7 +1316,7 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
                        break;
 
                case SCTP_CMD_UPDATE_ASSOC:
-                      sctp_assoc_update(asoc, cmd->obj.asoc);
+                      sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
                       break;
 
                case SCTP_CMD_PURGE_OUTQUEUE: