1 files changed, 130 insertions, 33 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 5e7fb0f54b88..caed19d90d06 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,
@@ -118,6 +124,13 @@ 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 +194,21 @@ 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 +468,17 @@ 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 +603,7 @@ 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 +2514,11 @@ 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 +2952,7 @@ 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,
@@ -3126,14 +3149,14 @@ 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;
 
@@ -3145,6 +3168,12 @@ 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));
 
@@ -3244,6 +3273,13 @@ 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
@@ -3658,6 +3694,16 @@ 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;
 }
@@ -3713,6 +3759,13 @@ 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;
 }
 
@@ -3720,12 +3773,14 @@ 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;
 
@@ -3734,30 +3789,51 @@ 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;
 }
@@ -3790,7 +3866,7 @@ 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));
 }
 
@@ -3809,10 +3885,31 @@ 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.
  ***************************************************************************/