ipvs: fix sctp chunk length order

Fix wrong but non-fatal access to chunk length.
sch->length should be in network order, next chunk should
be aligned to 4 bytes. Problem noticed in sparse output.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 9 insertions, 7 deletions

diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c
index ae8ec6f27688..cd1d7298f7ba 100644
--- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c
@@ -906,7 +906,7 @@ set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
         sctp_chunkhdr_t _sctpch, *sch;
         unsigned char chunk_type;
         int event, next_state;
-        int ihl;
+        int ihl, cofs;
 
 #ifdef CONFIG_IP_VS_IPV6
         ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
@@ -914,8 +914,8 @@ set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
         ihl = ip_hdrlen(skb);
 #endif
 
-        sch = skb_header_pointer(skb, ihl + sizeof(sctp_sctphdr_t),
-                                sizeof(_sctpch), &_sctpch);
+        cofs = ihl + sizeof(sctp_sctphdr_t);
+        sch = skb_header_pointer(skb, cofs, sizeof(_sctpch), &_sctpch);
         if (sch == NULL)
                 return;
 
@@ -933,10 +933,12 @@ set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
          */
         if ((sch->type == SCTP_CID_COOKIE_ECHO) ||
             (sch->type == SCTP_CID_COOKIE_ACK)) {
-                sch = skb_header_pointer(skb, (ihl + sizeof(sctp_sctphdr_t) +
-                                sch->length), sizeof(_sctpch), &_sctpch);
-                if (sch) {
-                        if (sch->type == SCTP_CID_ABORT)
+                int clen = ntohs(sch->length);
+
+                if (clen >= sizeof(sctp_chunkhdr_t)) {
+                        sch = skb_header_pointer(skb, cofs + ALIGN(clen, 4),
+                                                 sizeof(_sctpch), &_sctpch);
+                        if (sch && sch->type == SCTP_CID_ABORT)
                                 chunk_type = sch->type;
                 }
         }