zebra: Add a conditional guard if zvrf lookup fail

Add a conditional to guard against segfaulting on the debug
statement when zvrf lookup fails.

Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>

diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index f951738b703d6097c4592ecf7e043c46dfda3258..b1d0c1e3a69ee78099ef8e276fbaa1dc76750bec 100644 (file)
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -811,7 +811,9 @@ static int netlink_route_change_read_multicast(struct nlmsghdr *h,
        }
 
        if (IS_ZEBRA_DEBUG_KERNEL) {
-               struct interface *ifp;
+               struct interface *ifp = NULL;
+               struct zebra_vrf *zvrf = NULL;
+
                strlcpy(sbuf, inet_ntoa(m->sg.src), sizeof(sbuf));
                strlcpy(gbuf, inet_ntoa(m->sg.grp), sizeof(gbuf));
                for (count = 0; count < oif_count; count++) {
@@ -822,13 +824,14 @@ static int netlink_route_change_read_multicast(struct nlmsghdr *h,
                                oif[count]);
                        strlcat(oif_list, temp, sizeof(oif_list));
                }
-               struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(vrf);
+               zvrf = zebra_vrf_lookup_by_id(vrf);
                ifp = if_lookup_by_index(iif, vrf);
-               zlog_debug("MCAST VRF: %s(%d) %s (%s,%s) IIF: %s(%d) OIF: %s jiffies: %lld",
-                          zvrf->vrf->name, vrf,
-                          nl_msg_type_to_str(h->nlmsg_type),
-                          sbuf, gbuf, ifp ? ifp->name : "Unknown", iif,
-                          oif_list, m->lastused);
+               zlog_debug(
+                       "MCAST VRF: %s(%d) %s (%s,%s) IIF: %s(%d) OIF: %s jiffies: %lld",
+                       (zvrf ? zvrf->vrf->name : "Unknown"), vrf,
+                       nl_msg_type_to_str(h->nlmsg_type), sbuf, gbuf,
+                       ifp ? ifp->name : "Unknown", iif, oif_list,
+                       m->lastused);
        }
        return 0;
 }