Bluetooth: Fix properly ignoring unexpected SMP PDUs

If we didn't request certain pieces of information during the key
distribution negotiation we should properly ignore those PDUs if the
peer incorrectly sends them. This includes the Encryption Information
and Master Identification PDUs if the EncKey bit was not set, and the
Identity Information and Identity Address Information PDUs if the IdKey
bit was not set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/smp.c

@@ -891,6 +891,10 @@ static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
 	if (skb->len < sizeof(*rp))
 		return SMP_UNSPECIFIED;
 
+	/* Ignore this PDU if it wasn't requested */
+	if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
+		return 0;
+
 	skb_pull(skb, sizeof(*rp));
 
 	memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
@@ -911,6 +915,10 @@ static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
 	if (skb->len < sizeof(*rp))
 		return SMP_UNSPECIFIED;
 
+	/* Ignore this PDU if it wasn't requested */
+	if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
+		return 0;
+
 	skb_pull(skb, sizeof(*rp));
 
 	hci_dev_lock(hdev);
@@ -935,6 +943,10 @@ static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb)
 	if (skb->len < sizeof(*info))
 		return SMP_UNSPECIFIED;
 
+	/* Ignore this PDU if it wasn't requested */
+	if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
+		return 0;
+
 	skb_pull(skb, sizeof(*info));
 
 	memcpy(smp->irk, info->irk, 16);
@@ -955,6 +967,10 @@ static int smp_cmd_ident_addr_info(struct l2cap_conn *conn,
 	if (skb->len < sizeof(*info))
 		return SMP_UNSPECIFIED;
 
+	/* Ignore this PDU if it wasn't requested */
+	if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
+		return 0;
+
 	skb_pull(skb, sizeof(*info));
 
 	bacpy(&smp->id_addr, &info->bdaddr);