lib, zebra: Ensure that the ifp->node exists

On removal, ensure that the ifp->node is set to a null
pointer so that FRR does not use data after freed.
In addition ensure that the ifp->node exists before
attempting to free it.

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

2 files changed, 4 insertions, 0 deletions

diff --git a/lib/if.c b/lib/if.c
index 08d8918742..6f567861d1 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -1028,6 +1028,7 @@ void if_terminate(struct vrf *vrf)
 		if (ifp->node) {
 			ifp->node->info = NULL;
 			route_unlock_node(ifp->node);
+			ifp->node = NULL;
 		}
 		if_delete(&ifp);
 	}
diff --git a/zebra/interface.c b/zebra/interface.c
index 231ddc51db..ccf1a0a204 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -267,6 +267,9 @@ struct interface *if_link_per_ns(struct zebra_ns *ns, struct interface *ifp)
 /* Delete a VRF. This is called in vrf_terminate(). */
 void if_unlink_per_ns(struct interface *ifp)
 {
+	if (!ifp->node)
+		return;
+
 	ifp->node->info = NULL;
 	route_unlock_node(ifp->node);
 	ifp->node = NULL;