1 files changed, 46 insertions, 0 deletions

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 2e34220d94cd..23ae37ec8711 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2499,6 +2499,52 @@ 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;
+        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;
+
+                if (param.v > chunk_end - length ||
+                    length < sizeof(sctp_paramhdr_t))
+                        return 0;
+
+                switch (param.p->type) {
+                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;
+                        break;
+                case SCTP_PARAM_SUCCESS_REPORT:
+                case SCTP_PARAM_ADAPTATION_LAYER_IND:
+                        if (length != sizeof(sctp_addip_param_t))
+                                return 0;
+
+                        break;
+                default:
+                        break;
+                }
+
+                param.v += WORD_ROUND(length);
+        }
+
+        if (param.v != chunk_end)
+                return 0;
+
+        return 1;
+}
+
 /* Process an incoming ASCONF chunk with the next expected serial no. and
  * return an ASCONF_ACK chunk to be sent in response.
  */