zebra: Ensure stream is long enough

In zebra_evpn_proc_remote_nh if we do not pass in a long
enough stream, the stream reads will fail.  Ensure that
we have enough data.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

diff --git a/zebra/zebra_evpn_mh.c b/zebra/zebra_evpn_mh.c
index f0d4d2b8c971d6844cc7f85d58080b0e59b1acb2..c0cc57fc69eb0ada572b3e41aa852013bddad166 100644 (file)
--- a/zebra/zebra_evpn_mh.c
+++ b/zebra/zebra_evpn_mh.c
@@ -3920,8 +3920,18 @@ void zebra_evpn_proc_remote_nh(ZAPI_HANDLER_ARGS)
        struct ipaddr nh;
        struct ethaddr rmac;
        struct prefix_evpn dummy_prefix;
+       size_t min_len = 4 + sizeof(nh);
 
        s = msg;
+
+       /*
+        * Ensure that the stream sent to us is long enough
+        */
+       if (hdr->command == ZEBRA_EVPN_REMOTE_NH_ADD)
+               min_len += sizeof(rmac);
+       if (hdr->length < min_len)
+               return;
+
        vrf_id = stream_getl(s);
        stream_get(&nh, s, sizeof(nh));