[media] vp7045: fix buffer setup

dvb_usb_device_init calls the frontend_attach method of this driver which
uses vp7045_usb_ob. In order to have a buffer ready in vp7045_usb_op, it has to
be allocated before that happens.

Luckily we can use the whole private data as the buffer as it gets separately
allocated on the heap via kzalloc in dvb_usb_device_init and is thus apt for
use via usb_control_msg.

This fixes a
	BUG: unable to handle kernel paging request at 0000000000001e78

reported by Tino Keitel and diagnosed by Dan Carpenter.

Cc: stable@kernel.org # For v3.0 and upper
Tested-by: Tino Keitel <tino.keitel@tikei.de>
Signed-off-by: Florian Mickler <florian@mickler.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 4 insertions, 22 deletions

diff --git a/drivers/media/dvb/dvb-usb/vp7045.c b/drivers/media/dvb/dvb-usb/vp7045.c
index 3db89e3cb0bb..536c16c943bd 100644
--- a/drivers/media/dvb/dvb-usb/vp7045.c
+++ b/drivers/media/dvb/dvb-usb/vp7045.c
@@ -224,26 +224,8 @@ static struct dvb_usb_device_properties vp7045_properties;
 static int vp7045_usb_probe(struct usb_interface *intf,
                 const struct usb_device_id *id)
 {
-        struct dvb_usb_device *d;
-        int ret = dvb_usb_device_init(intf, &vp7045_properties,
-                                   THIS_MODULE, &d, adapter_nr);
-        if (ret)
-                return ret;
-
-        d->priv = kmalloc(20, GFP_KERNEL);
-        if (!d->priv) {
-                dvb_usb_device_exit(intf);
-                return -ENOMEM;
-        }
-
-        return ret;
-}
-
-static void vp7045_usb_disconnect(struct usb_interface *intf)
-{
-        struct dvb_usb_device *d = usb_get_intfdata(intf);
-        kfree(d->priv);
-        dvb_usb_device_exit(intf);
+        return dvb_usb_device_init(intf, &vp7045_properties,
+                                   THIS_MODULE, NULL, adapter_nr);
 }
 
 static struct usb_device_id vp7045_usb_table [] = {
@@ -258,7 +240,7 @@ MODULE_DEVICE_TABLE(usb, vp7045_usb_table);
 static struct dvb_usb_device_properties vp7045_properties = {
         .usb_ctrl = CYPRESS_FX2,
         .firmware = "dvb-usb-vp7045-01.fw",
-        .size_of_priv = sizeof(u8 *),
+        .size_of_priv = 20,
 
         .num_adapters = 1,
         .adapter = {
@@ -305,7 +287,7 @@ static struct dvb_usb_device_properties vp7045_properties = {
 static struct usb_driver vp7045_usb_driver = {
         .name           = "dvb_usb_vp7045",
         .probe          = vp7045_usb_probe,
-        .disconnect     = vp7045_usb_disconnect,
+        .disconnect     = dvb_usb_device_exit,
         .id_table       = vp7045_usb_table,
 };