bgpd: fix bgp label evpn CID 1636504

The following static analysis can be seen :

> *** CID 1636504:    (ARRAY_VS_SINGLETON)
> /bgpd/bgp_evpn_mh.c: 1241 in bgp_evpn_type1_route_process()
> 1235            build_evpn_type1_prefix(&p, eth_tag, &esi, vtep_ip);
> 1236            /* Process the route. */
> 1237            if (attr) {
> 1238                    bgp_update(peer, (struct prefix *)&p, addpath_id, attr, afi, safi, ZEBRA_ROUTE_BGP,
> 1239                               BGP_ROUTE_NORMAL, &prd, &label, num_labels, 0, NULL);
> 1240            } else {
> >>>     CID 1636504:    (ARRAY_VS_SINGLETON)
> >>>     Passing "&label" to function "bgp_withdraw" which uses it as an array. This might corrupt or misinterpret adjacent memory locations.
> 1241                    bgp_withdraw(peer, (struct prefix *)&p, addpath_id, afi, safi, ZEBRA_ROUTE_BGP,
> 1242                                 BGP_ROUTE_NORMAL, &prd, &label, num_labels);
> 1243            }
> 1244            return 0;
> 1245     }
> 1246
> /bgpd/bgp_evpn_mh.c: 1238 in bgp_evpn_type1_route_process()
> 1232             * table
> 1233             */
> 1234            vtep_ip.s_addr = INADDR_ANY;
> 1235            build_evpn_type1_prefix(&p, eth_tag, &esi, vtep_ip);
> 1236            /* Process the route. */
> 1237            if (attr) {
> >>>     CID 1636504:    (ARRAY_VS_SINGLETON)
> >>>     Passing "&label" to function "bgp_update" which uses it as an array. This might corrupt or misinterpret adjacent memory locations.
> 1238                    bgp_update(peer, (struct prefix *)&p, addpath_id, attr, afi, safi, ZEBRA_ROUTE_BGP,
> 1239                               BGP_ROUTE_NORMAL, &prd, &label, num_labels, 0, NULL);
> 1240            } else {
> 1241                    bgp_withdraw(peer, (struct prefix *)&p, addpath_id, afi, safi, ZEBRA_ROUTE_BGP,
> 1242                                 BGP_ROUTE_NORMAL, &prd, &label, num_labels);
> 1243            }

Fix this by declaring a label array instead of a single array.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
(cherry picked from commit ba462af2e3a4a242b2ffcde6074750f851632777)

diff --git a/bgpd/bgp_evpn_mh.c b/bgpd/bgp_evpn_mh.c
index 7fd4bb91e2db90eecb8b151b1cf10e6da29b7e15..57f638240d5538ad7c214d8c850c2366836f996f 100644 (file)
--- a/bgpd/bgp_evpn_mh.c
+++ b/bgpd/bgp_evpn_mh.c
@@ -1198,7 +1198,7 @@ int bgp_evpn_type1_route_process(struct peer *peer, afi_t afi, safi_t safi,
        struct prefix_rd prd;
        esi_t esi;
        uint32_t eth_tag;
-       mpls_label_t label;
+       mpls_label_t label[BGP_MAX_LABELS] = {};
        struct in_addr vtep_ip;
        struct prefix_evpn p;
 
@@ -1224,7 +1224,7 @@ int bgp_evpn_type1_route_process(struct peer *peer, afi_t afi, safi_t safi,
        eth_tag = ntohl(eth_tag);
        pfx += EVPN_ETH_TAG_BYTES;
 
-       memcpy(&label, pfx, BGP_LABEL_BYTES);
+       memcpy(&label[0], pfx, BGP_LABEL_BYTES);
 
        /* EAD route prefix doesn't include the nexthop in the global
         * table
@@ -1234,10 +1234,10 @@ int bgp_evpn_type1_route_process(struct peer *peer, afi_t afi, safi_t safi,
        /* Process the route. */
        if (attr) {
                bgp_update(peer, (struct prefix *)&p, addpath_id, attr, afi, safi, ZEBRA_ROUTE_BGP,
-                          BGP_ROUTE_NORMAL, &prd, &label, 1, 0, NULL);
+                          BGP_ROUTE_NORMAL, &prd, &label[0], 1, 0, NULL);
        } else {
                bgp_withdraw(peer, (struct prefix *)&p, addpath_id, afi, safi, ZEBRA_ROUTE_BGP,
-                            BGP_ROUTE_NORMAL, &prd, &label, 1);
+                            BGP_ROUTE_NORMAL, &prd, &label[0], 1);
        }
        return 0;
 }