Bluetooth: Free potentially unfreed SCO connection

It is possible to initiate a SCO connection while deleting the
corresponding ACL connection, e.g. in below scenario:

(1) < hci setup sync connect command
(2) > hci disconn complete event (for the acl connection)
(3) > hci command complete event (for(1), failure)

When it happens, hci_cs_setup_sync_conn won't be able to obtain the
reference to the SCO connection, so it will be stuck and potentially
hinder subsequent connections to the same device.

This patch prevents that by also deleting the SCO connection if it is
still not established when the corresponding ACL connection is deleted.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Ying Hsu <yinghsu@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 61a34801e61eaef148dbb7ef86e35ac9d09d0f74..838f51c272a66c0b8d7be2ef62f8fff250c3780e 100644 (file)
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1061,8 +1061,15 @@ int hci_conn_del(struct hci_conn *conn)
 
        if (conn->type == ACL_LINK) {
                struct hci_conn *sco = conn->link;
-               if (sco)
+               if (sco) {
                        sco->link = NULL;
+                       /* Due to race, SCO connection might be not established
+                        * yet at this point. Delete it now, otherwise it is
+                        * possible for it to be stuck and can't be deleted.
+                        */
+                       if (sco->handle == HCI_CONN_HANDLE_UNSET)
+                               hci_conn_del(sco);
+               }
 
                /* Unacked frames */
                hdev->acl_cnt += conn->sent;