1 files changed, 204 insertions, 39 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 177528ed3e1b..a583d67cab63 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -90,6 +90,11 @@ static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
                                              const sctp_subtype_t type,
                                              void *arg,
                                              sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
+                                        const struct sctp_association *asoc,
+                                        const sctp_subtype_t type,
+                                        void *arg,
+                                        sctp_cmd_seq_t *commands);
 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
 
 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
@@ -98,6 +103,7 @@ static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
                                            struct sctp_transport *transport);
 
 static sctp_disposition_t sctp_sf_abort_violation(
+                                     const struct sctp_endpoint *ep,
                                      const struct sctp_association *asoc,
                                      void *arg,
                                      sctp_cmd_seq_t *commands,
@@ -111,6 +117,13 @@ static sctp_disposition_t sctp_sf_violation_chunklen(
                                      void *arg,
                                      sctp_cmd_seq_t *commands);
 
+static sctp_disposition_t sctp_sf_violation_paramlen(
+                                     const struct sctp_endpoint *ep,
+                                     const struct sctp_association *asoc,
+                                     const sctp_subtype_t type,
+                                     void *arg,
+                                     sctp_cmd_seq_t *commands);
+
 static sctp_disposition_t sctp_sf_violation_ctsn(
                                      const struct sctp_endpoint *ep,
                                      const struct sctp_association *asoc,
@@ -118,6 +131,13 @@ static sctp_disposition_t sctp_sf_violation_ctsn(
                                      void *arg,
                                      sctp_cmd_seq_t *commands);
 
+static sctp_disposition_t sctp_sf_violation_chunk(
+                                     const struct sctp_endpoint *ep,
+                                     const struct sctp_association *asoc,
+                                     const sctp_subtype_t type,
+                                     void *arg,
+                                     sctp_cmd_seq_t *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.
@@ -181,16 +201,21 @@ sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
         struct sctp_chunk *chunk = arg;
         struct sctp_ulpevent *ev;
 
+        if (!sctp_vtag_verify_either(chunk, asoc))
+                return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+
         /* RFC 2960 6.10 Bundling
          *
          * An endpoint MUST NOT bundle INIT, INIT ACK or
          * SHUTDOWN COMPLETE with any other chunks.
          */
         if (!chunk->singleton)
-                return SCTP_DISPOSITION_VIOLATION;
+                return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
 
-        if (!sctp_vtag_verify_either(chunk, asoc))
-                return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+        /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
+        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
 
         /* RFC 2960 10.2 SCTP-to-ULP
          *
@@ -450,17 +475,17 @@ sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
         if (!sctp_vtag_verify(chunk, asoc))
                 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
 
-        /* Make sure that the INIT-ACK chunk has a valid length */
-        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
-                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
-                                                  commands);
         /* 6.10 Bundling
          * An endpoint MUST NOT bundle INIT, INIT ACK or
          * SHUTDOWN COMPLETE with any other chunks.
          */
         if (!chunk->singleton)
-                return SCTP_DISPOSITION_VIOLATION;
+                return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
 
+        /* Make sure that the INIT-ACK chunk has a valid length */
+        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
+                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
         /* Grab the INIT header.  */
         chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
 
@@ -585,7 +610,7 @@ sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
          * control endpoint, respond with an ABORT.
          */
         if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
-                return sctp_sf_ootb(ep, asoc, type, arg, commands);
+                return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
 
         /* Make sure that the COOKIE_ECHO chunk has a valid length.
          * In this case, we check that we have enough for at least a
@@ -2496,6 +2521,11 @@ sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
         struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
         struct sctp_chunk *reply;
 
+        /* Make sure that the chunk has a valid length */
+        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
+
         /* Since we are not going to really process this INIT, there
          * is no point in verifying chunk boundries.  Just generate
          * the SHUTDOWN ACK.
@@ -2929,7 +2959,7 @@ sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
  *
  * The return value is the disposition of the chunk.
 */
-sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
+static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
                                         const struct sctp_association *asoc,
                                         const sctp_subtype_t type,
                                         void *arg,
@@ -2965,6 +2995,7 @@ sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
 
                 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
 
+                sctp_sf_pdiscard(ep, asoc, type, arg, commands);
                 return SCTP_DISPOSITION_CONSUME;
         }
 
@@ -3125,14 +3156,14 @@ sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
 
         ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
         do {
-                /* Break out if chunk length is less then minimal. */
+                /* Report violation if the chunk is less then minimal */
                 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
-                        break;
-
-                ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
-                if (ch_end > skb_tail_pointer(skb))
-                        break;
+                        return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
 
+                /* Now that we know we at least have a chunk header,
+                 * do things that are type appropriate.
+                 */
                 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
                         ootb_shut_ack = 1;
 
@@ -3144,15 +3175,19 @@ sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
                 if (SCTP_CID_ABORT == ch->type)
                         return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
 
+                /* Report violation if chunk len overflows */
+                ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+                if (ch_end > skb_tail_pointer(skb))
+                        return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
+
                 ch = (sctp_chunkhdr_t *) ch_end;
         } while (ch_end < skb_tail_pointer(skb));
 
         if (ootb_shut_ack)
-                sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
+                return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
         else
-                sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
-
-        return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
+                return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
 }
 
 /*
@@ -3218,7 +3253,11 @@ static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
                 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
                         return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
 
-                return SCTP_DISPOSITION_CONSUME;
+                /* We need to discard the rest of the packet to prevent
+                 * potential bomming attacks from additional bundled chunks.
+                 * This is documented in SCTP Threats ID.
+                 */
+                return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
         }
 
         return SCTP_DISPOSITION_NOMEM;
@@ -3241,6 +3280,13 @@ sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
                                       void *arg,
                                       sctp_cmd_seq_t *commands)
 {
+        struct sctp_chunk *chunk = arg;
+
+        /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
+        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
+
         /* Although we do have an association in this case, it corresponds
          * to a restarted association. So the packet is treated as an OOTB
          * packet and the state function that handles OOTB SHUTDOWN_ACK is
@@ -3257,8 +3303,11 @@ sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
 {
         struct sctp_chunk       *chunk = arg;
         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,
@@ -3274,6 +3323,20 @@ sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
         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(ep, asoc, type,
+                           (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))
+                return sctp_sf_violation_paramlen(ep, asoc, type,
+                           (void *)&err_param, commands);
+
         /* ADDIP 4.2 C1) Compare the value of the serial number to the value
          * the endpoint stored in a new association variable
          * 'Peer-Serial-Number'.
@@ -3328,6 +3391,7 @@ sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
         struct sctp_chunk       *asconf_ack = arg;
         struct sctp_chunk       *last_asconf = asoc->addip_last_asconf;
         struct sctp_chunk       *abort;
+        struct sctp_paramhdr    *err_param = NULL;
         sctp_addiphdr_t         *addip_hdr;
         __u32                   sent_serial, rcvd_serial;
 
@@ -3345,6 +3409,14 @@ sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
         addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
         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))
+                return sctp_sf_violation_paramlen(ep, asoc, type,
+                           (void *)&err_param, commands);
+
         if (last_asconf) {
                 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
                 sent_serial = ntohl(addip_hdr->serial);
@@ -3655,6 +3727,16 @@ sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
                                          void *arg,
                                          sctp_cmd_seq_t *commands)
 {
+        struct sctp_chunk *chunk = arg;
+
+        /* 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.
+         */
+        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
+
         SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
         return SCTP_DISPOSITION_DISCARD;
 }
@@ -3710,6 +3792,13 @@ sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
                                      void *arg,
                                      sctp_cmd_seq_t *commands)
 {
+        struct sctp_chunk *chunk = arg;
+
+        /* Make sure that the chunk has a valid length. */
+        if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+                return sctp_sf_violation_chunklen(ep, asoc, type, arg,
+                                                  commands);
+
         return SCTP_DISPOSITION_VIOLATION;
 }
 
@@ -3717,12 +3806,14 @@ sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
  * Common function to handle a protocol violation.
  */
 static sctp_disposition_t sctp_sf_abort_violation(
+                                     const struct sctp_endpoint *ep,
                                      const struct sctp_association *asoc,
                                      void *arg,
                                      sctp_cmd_seq_t *commands,
                                      const __u8 *payload,
                                      const size_t paylen)
 {
+        struct sctp_packet *packet = NULL;
         struct sctp_chunk *chunk =  arg;
         struct sctp_chunk *abort = NULL;
 
@@ -3731,30 +3822,51 @@ static sctp_disposition_t sctp_sf_abort_violation(
         if (!abort)
                 goto nomem;
 
-        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
-        SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
+        if (asoc) {
+                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+                SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
 
-        if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
-                sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
-                                SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
-                sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
-                                SCTP_ERROR(ECONNREFUSED));
-                sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
-                                SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+                if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
+                        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+                        sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+                                        SCTP_ERROR(ECONNREFUSED));
+                        sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+                                        SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+                } else {
+                        sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+                                        SCTP_ERROR(ECONNABORTED));
+                        sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+                                        SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+                        SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
+                }
         } else {
-                sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
-                                SCTP_ERROR(ECONNABORTED));
-                sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
-                                SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
-                SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
+                packet = sctp_ootb_pkt_new(asoc, chunk);
+
+                if (!packet)
+                        goto nomem_pkt;
+
+                if (sctp_test_T_bit(abort))
+                        packet->vtag = ntohl(chunk->sctp_hdr->vtag);
+
+                abort->skb->sk = ep->base.sk;
+
+                sctp_packet_append_chunk(packet, abort);
+
+                sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+                        SCTP_PACKET(packet));
+
+                SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
         }
 
-        sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+        sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
 
         SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
 
         return SCTP_DISPOSITION_ABORT;
 
+nomem_pkt:
+        sctp_chunk_free(abort);
 nomem:
         return SCTP_DISPOSITION_NOMEM;
 }
@@ -3787,7 +3899,24 @@ static sctp_disposition_t sctp_sf_violation_chunklen(
 {
         char err_str[]="The following chunk had invalid length:";
 
-        return sctp_sf_abort_violation(asoc, arg, commands, err_str,
+        return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+                                        sizeof(err_str));
+}
+
+/*
+ * Handle a protocol violation when the parameter length is invalid.
+ * "Invalid" length is identified as smaller then the minimal length a
+ * given parameter can be.
+ */
+static sctp_disposition_t sctp_sf_violation_paramlen(
+                                     const struct sctp_endpoint *ep,
+                                     const struct sctp_association *asoc,
+                                     const sctp_subtype_t type,
+                                     void *arg,
+                                     sctp_cmd_seq_t *commands) {
+        char err_str[] = "The following parameter had invalid length:";
+
+        return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
                                         sizeof(err_str));
 }
 
@@ -3806,10 +3935,31 @@ static sctp_disposition_t sctp_sf_violation_ctsn(
 {
         char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
 
-        return sctp_sf_abort_violation(asoc, arg, commands, err_str,
+        return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
                                         sizeof(err_str));
 }
 
+/* Handle protocol violation of an invalid chunk bundling.  For example,
+ * when we have an association and we recieve bundled INIT-ACK, or
+ * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
+ * statement from the specs.  Additinally, there might be an attacker
+ * on the path and we may not want to continue this communication.
+ */
+static sctp_disposition_t sctp_sf_violation_chunk(
+                                     const struct sctp_endpoint *ep,
+                                     const struct sctp_association *asoc,
+                                     const sctp_subtype_t type,
+                                     void *arg,
+                                     sctp_cmd_seq_t *commands)
+{
+        char err_str[]="The following chunk violates protocol:";
+
+        if (!asoc)
+                return sctp_sf_violation(ep, asoc, type, arg, commands);
+
+        return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+                                        sizeof(err_str));
+}
 /***************************************************************************
  * These are the state functions for handling primitive (Section 10) events.
  ***************************************************************************/
@@ -5176,7 +5326,22 @@ static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc
          * association exists, otherwise, use the peer's vtag.
          */
         if (asoc) {
-                vtag = asoc->peer.i.init_tag;
+                /* Special case the INIT-ACK as there is no peer's vtag
+                 * yet.
+                 */
+                switch(chunk->chunk_hdr->type) {
+                case SCTP_CID_INIT_ACK:
+                {
+                        sctp_initack_chunk_t *initack;
+
+                        initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
+                        vtag = ntohl(initack->init_hdr.init_tag);
+                        break;
+                }
+                default:
+                        vtag = asoc->peer.i.init_tag;
+                        break;
+                }
         } else {
                 /* Special case the INIT and stale COOKIE_ECHO as there is no
                  * vtag yet.