mei: fix out of array access to me clients array

The patch 9f81abdac362: "mei: implement mei_cl_connect function"
from Jan 8, 2013, leads to the following static checker warning:
"drivers/misc/mei/main.c:522 mei_ioctl_connect_client()
	 warn: check 'dev->me_clients[]' for negative offsets (-2)"

Reported-by: Dan Carpenter <dan.carpenter@oracle.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/main.c b/drivers/misc/mei/main.c
index 7c44c8d..053139f 100644 (file)
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -489,11 +489,16 @@ static int mei_ioctl_connect_client(struct file *file,
 
        /* find ME client we're trying to connect to */
        i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
-       if (i >= 0 && !dev->me_clients[i].props.fixed_address) {
-               cl->me_client_id = dev->me_clients[i].client_id;
-               cl->state = MEI_FILE_CONNECTING;
+       if (i < 0 || dev->me_clients[i].props.fixed_address) {
+               dev_dbg(&dev->pdev->dev, "Cannot connect to FW Client UUID = %pUl\n",
+                               &data->in_client_uuid);
+               rets = -ENODEV;
+               goto end;
        }
 
+       cl->me_client_id = dev->me_clients[i].client_id;
+       cl->state = MEI_FILE_CONNECTING;
+
        dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
                        cl->me_client_id);
        dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
@@ -527,11 +532,6 @@ static int mei_ioctl_connect_client(struct file *file,
                goto end;
        }
 
-       if (cl->state != MEI_FILE_CONNECTING) {
-               rets = -ENODEV;
-               goto end;
-       }
-
 
        /* prepare the output buffer */
        client = &data->out_client_properties;
@@ -543,7 +543,6 @@ static int mei_ioctl_connect_client(struct file *file,
        rets = mei_cl_connect(cl, file);
 
 end:
-       dev_dbg(&dev->pdev->dev, "free connect cb memory.");
        return rets;
 }