mei: fix NULL dereferencing during FW initiated disconnection

commit 6a8d648c8d1824117a9e9edb948ed1611fb013c0 upstream.

In the case when disconnection is initiated from the FW
the driver is flushing items from the write control list while
iterating over it:

mei_irq_write_handler()
    list_for_each_entry_safe(ctrl_wr_list)         <-- outer loop
         mei_cl_irq_disconnect_rsp()
             mei_cl_set_disconnected()
                 mei_io_list_flush(ctrl_wr_list)   <-- destorying list

We move the list flushing to the completion routine.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index a6c87c713193808365071a8e0ad34fd17cea0eab..958af84884b57e8af7b68df6d3ab7319a963b583 100644 (file)
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1734,6 +1734,10 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
                if (waitqueue_active(&cl->wait))
                        wake_up(&cl->wait);
 
+               break;
+       case MEI_FOP_DISCONNECT_RSP:
+               mei_io_cb_free(cb);
+               mei_cl_set_disconnected(cl);
                break;
        default:
                BUG_ON(0);

diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index e7b7aad0999bc665e01da3c94b75ee91caa86c31..fd8a9f057ea644227e779e00febdfa3836e811fd 100644 (file)
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -873,8 +873,7 @@ static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
                cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT_RSP, NULL);
                if (!cb)
                        return -ENOMEM;
-               cl_dbg(dev, cl, "add disconnect response as first\n");
-               list_add(&cb->list, &dev->ctrl_wr_list.list);
+               list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
        }
        return 0;
 }

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 64b568a0268d7026d7305f3233c378900e5669f4..44471edb62f7fcf48f75e704fed634187e441dfb 100644 (file)
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -184,10 +184,7 @@ static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
                return -EMSGSIZE;
 
        ret = mei_hbm_cl_disconnect_rsp(dev, cl);
-       mei_cl_set_disconnected(cl);
-       mei_io_cb_free(cb);
-       mei_me_cl_put(cl->me_cl);
-       cl->me_cl = NULL;
+       list_move_tail(&cb->list, &cmpl_list->list);
 
        return ret;
 }