From c7a6252b9472fd96a3dbac40c891eb9f4fe5b4f1 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin <alexander.usyskin@intel.com> Date: Thu, 29 Oct 2020 11:54:43 +0200 Subject: [PATCH] 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> --- drivers/misc/mei/bus.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c index 9cdaa7f3af23..1a54bf3ed0c3 100644 --- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -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;