Bluetooth: Fix SMP security elevation from medium to high

If we have an unauthenticated key it is not sufficient to acheive high
security. Therefore, when deciding whether to encrypt the link or
request pairing, it is essential to in addition to checking the
existence of a key to also check whether it is authenticated or not.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index c4ac2849d9c2a195c2b65fbda6d9855253b0d5b9..37df4e9b3896435164adf36a0c52b8ab8c08030c 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -703,7 +703,7 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
        return 0;
 }
 
-static u8 smp_ltk_encrypt(struct l2cap_conn *conn)
+static u8 smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
 {
        struct smp_ltk *key;
        struct hci_conn *hcon = conn->hcon;
@@ -712,6 +712,9 @@ static u8 smp_ltk_encrypt(struct l2cap_conn *conn)
        if (!key)
                return 0;
 
+       if (sec_level > BT_SECURITY_MEDIUM && !key->authenticated)
+               return 0;
+
        if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
                return 1;
 
@@ -732,7 +735,7 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
 
        hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req);
 
-       if (smp_ltk_encrypt(conn))
+       if (smp_ltk_encrypt(conn, hcon->pending_sec_level))
                return 0;
 
        if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
@@ -771,7 +774,7 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
                return 1;
 
        if (hcon->link_mode & HCI_LM_MASTER)
-               if (smp_ltk_encrypt(conn))
+               if (smp_ltk_encrypt(conn, sec_level))
                        goto done;
 
        if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))