Bluetooth: Fix ignoring unknown SMP authentication requirement bits

The SMP specification states that we should ignore any unknown bits from
the authentication requirement. We already have a define for masking out
unknown bits but we haven't used it in all places so far. This patch
adds usage of the AUTH_REQ_MASK to all places that need it and ensures
that we don't pass unknown bits onward to other functions.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 13 insertions, 9 deletions

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index dbd17a07dc2e..ef8f96d2c059 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -949,8 +949,11 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
         if (!smp)
                 return SMP_UNSPECIFIED;
 
+        /* We didn't start the pairing, so match remote */
+        auth = req->auth_req & AUTH_REQ_MASK;
+
         if (!test_bit(HCI_BONDABLE, &hdev->dev_flags) &&
-            (req->auth_req & SMP_AUTH_BONDING))
+            (auth & SMP_AUTH_BONDING))
                 return SMP_PAIRING_NOTSUPP;
 
         SMP_DISALLOW_CMD(smp, SMP_CMD_PAIRING_REQ);
@@ -959,9 +962,6 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
         memcpy(&smp->preq[1], req, sizeof(*req));
         skb_pull(skb, sizeof(*req));
 
-        /* We didn't start the pairing, so match remote */
-        auth = req->auth_req;
-
         sec_level = authreq_to_seclevel(auth);
         if (sec_level > conn->hcon->pending_sec_level)
                 conn->hcon->pending_sec_level = sec_level;
@@ -1024,6 +1024,8 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
         if (check_enc_key_size(conn, key_size))
                 return SMP_ENC_KEY_SIZE;
 
+        auth = rsp->auth_req & AUTH_REQ_MASK;
+
         /* If we need MITM check that it can be acheived */
         if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) {
                 u8 method;
@@ -1044,7 +1046,7 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
          */
         smp->remote_key_dist &= rsp->resp_key_dist;
 
-        auth = (req->auth_req | rsp->auth_req);
+        auth |= req->auth_req;
 
         ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability);
         if (ret)
@@ -1160,7 +1162,7 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
         struct smp_cmd_pairing cp;
         struct hci_conn *hcon = conn->hcon;
         struct smp_chan *smp;
-        u8 sec_level;
+        u8 sec_level, auth;
 
         BT_DBG("conn %p", conn);
 
@@ -1170,7 +1172,9 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
         if (hcon->role != HCI_ROLE_MASTER)
                 return SMP_CMD_NOTSUPP;
 
-        sec_level = authreq_to_seclevel(rp->auth_req);
+        auth = rp->auth_req & AUTH_REQ_MASK;
+
+        sec_level = authreq_to_seclevel(auth);
         if (smp_sufficient_security(hcon, sec_level))
                 return 0;
 
@@ -1185,13 +1189,13 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
                 return SMP_UNSPECIFIED;
 
         if (!test_bit(HCI_BONDABLE, &hcon->hdev->dev_flags) &&
-            (rp->auth_req & SMP_AUTH_BONDING))
+            (auth & SMP_AUTH_BONDING))
                 return SMP_PAIRING_NOTSUPP;
 
         skb_pull(skb, sizeof(*rp));
 
         memset(&cp, 0, sizeof(cp));
-        build_pairing_cmd(conn, &cp, NULL, rp->auth_req);
+        build_pairing_cmd(conn, &cp, NULL, auth);
 
         smp->preq[0] = SMP_CMD_PAIRING_REQ;
         memcpy(&smp->preq[1], &cp, sizeof(cp));