diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c
index f774b7e52da4..e37d9a05f307 100644
--- a/drivers/net/ppp/ppp_synctty.c
+++ b/drivers/net/ppp/ppp_synctty.c
@@ -699,7 +699,7 @@ ppp_sync_input(struct syncppp *ap, const unsigned char *buf,
 
 	/* strip address/control field if present */
 	p = skb->data;
-	if (p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
+	if (skb->len >= 2 && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
 		/* chop off address/control */
 		if (skb->len < 3)
 			goto err;