Backport of
https://anongit.mindrot.org/openssh.git/patch/?id=28652bca29046f62c7045e933e6b931de1d16737

--- openssh-7.3p1/kex.c
+++ openssh-7.3p1/kex.c
@@ -419,6 +419,8 @@
 	ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_protocol_error);
 	if ((r = sshpkt_get_end(ssh)) != 0)
 		return r;
+	if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0)
+		return r;
 	kex->done = 1;
 	sshbuf_reset(kex->peer);
 	/* sshbuf_reset(kex->my); */
--- openssh-7.3p1/packet.c
+++ openssh-7.3p1/packet.c
@@ -1919,9 +1919,7 @@
 			return r;
 		return SSH_ERR_PROTOCOL_ERROR;
 	}
-	if (*typep == SSH2_MSG_NEWKEYS)
-		r = ssh_set_newkeys(ssh, MODE_IN);
-	else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
+	if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
 		r = ssh_packet_enable_delayed_compress(ssh);
 	else
 		r = 0;
