NFC: llcp: Clean local timers and works when removing a device

Whenever an adapter is removed we must clean all the local structures,
especially the timers and scheduled work. Otherwise those asynchronous
threads will eventually try to access the freed nfc_dev pointer if an LLCP
link is up.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
index 7f8266dd14cbc164a278aa3bbc0438c845fa0bf5..77e1d97b3996e87ccb8547975f4f48454a6010ee 100644 (file)
--- a/net/nfc/llcp/llcp.c
+++ b/net/nfc/llcp/llcp.c
@@ -142,20 +142,25 @@ struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
        return local;
 }
 
-static void local_release(struct kref *ref)
+static void local_cleanup(struct nfc_llcp_local *local, bool listen)
 {
-       struct nfc_llcp_local *local;
-
-       local = container_of(ref, struct nfc_llcp_local, ref);
-
-       list_del(&local->list);
-       nfc_llcp_socket_release(local, false);
+       nfc_llcp_socket_release(local, listen);
        del_timer_sync(&local->link_timer);
        skb_queue_purge(&local->tx_queue);
        cancel_work_sync(&local->tx_work);
        cancel_work_sync(&local->rx_work);
        cancel_work_sync(&local->timeout_work);
        kfree_skb(local->rx_pending);
+}
+
+static void local_release(struct kref *ref)
+{
+       struct nfc_llcp_local *local;
+
+       local = container_of(ref, struct nfc_llcp_local, ref);
+
+       list_del(&local->list);
+       local_cleanup(local, false);
        kfree(local);
 }
 
@@ -1427,6 +1432,8 @@ void nfc_llcp_unregister_device(struct nfc_dev *dev)
                return;
        }
 
+       local_cleanup(local, false);
+
        nfc_llcp_local_put(local);
 }