Bluetooth: Free potentially unfreed SCO connection

commit 0f00cd322d22d4441de51aa80bcce5bb6a8cbb44 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 09e7f84..2634cb4 100644 (file)
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1063,8 +1063,15 @@ 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;