Bluetooth: Fix race condition with conn->sec_level

The conn->sec_level value is supposed to represent the current level of
security that the connection has. However, by assigning to it before
requesting authentication it will have the wrong value during the
authentication procedure. To fix this a pending_sec_level variable is
added which is used to track the desired security level while making
sure that sec_level always represents the current level of security.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

1 files changed, 6 insertions, 2 deletions

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index fe712a89a856..99cd8d9d891b 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -379,7 +379,8 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
         hci_conn_hold(acl);
 
         if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
-                acl->sec_level = sec_level;
+                acl->sec_level = BT_SECURITY_LOW;
+                acl->pending_sec_level = sec_level;
                 acl->auth_type = auth_type;
                 hci_acl_connect(acl);
         }
@@ -437,8 +438,11 @@ static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
 {
         BT_DBG("conn %p", conn);
 
+        if (conn->pending_sec_level > sec_level)
+                sec_level = conn->pending_sec_level;
+
         if (sec_level > conn->sec_level)
-                conn->sec_level = sec_level;
+                conn->pending_sec_level = sec_level;
         else if (conn->link_mode & HCI_LM_AUTH)
                 return 1;