SCTP : Add paramters validity check for ASCONF chunk

If ADDIP is enabled, when an ASCONF chunk is received with ASCONF
paramter length set to zero, this will cause infinite loop.
By the way, if an malformed ASCONF chunk is received, will cause
processing to access memory without verifying.

This is because of not check the validity of parameters in ASCONF chunk.
This patch fixed this.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index cc71f366d1cd..e8e3a64eb322 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -246,6 +246,9 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
                                               int, __be16);
 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
                                              union sctp_addr *addr);
+int sctp_verify_asconf(const struct sctp_association *asoc,
+                       struct sctp_paramhdr *param_hdr, void *chunk_end,
+                       struct sctp_paramhdr **errp);
 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
                                        struct sctp_chunk *asconf);
 int sctp_process_asconf_ack(struct sctp_association *asoc,
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index c2fe2dcc9afc..490a2928817c 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -421,6 +421,7 @@ struct sctp_signed_cookie {
  * internally.
  */
 union sctp_addr_param {
+        struct sctp_paramhdr p;
         struct sctp_ipv4addr_param v4;
         struct sctp_ipv6addr_param v6;
 };