mei: bus: do not start a read for disconnected clients

Avoid queuing reads and registering rx callbacks in
case the client is not connected, to prevent null
dereferencing and memory leaks.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20201029095444.957924-3-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexander Usyskin 2020-10-29 11:54:43 +02:00 committed by Greg Kroah-Hartman
parent a7c392c76a
commit c7a6252b94

View file

@ -276,7 +276,8 @@ static void mei_cl_bus_rx_work(struct work_struct *work)
cldev->rx_cb(cldev);
mutex_lock(&bus->device_lock);
mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
if (mei_cl_is_connected(cldev->cl))
mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
mutex_unlock(&bus->device_lock);
}
@ -364,7 +365,10 @@ int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
mutex_lock(&bus->device_lock);
ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
if (mei_cl_is_connected(cldev->cl))
ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
else
ret = -ENODEV;
mutex_unlock(&bus->device_lock);
if (ret && ret != -EBUSY)
return ret;