[media] cx88-dvb avoid dangling core->gate_ctrl pointer

dvb_register calls videobuf_dvb_register_bus, but if that returns
a failure the module will be unloaded without clearing the
value of core->gate_ctrl which will cause an oops in macros
called from video_open in cx88-video.c

Signed-off-by: David Fries <David@Fries.net>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Istvan Varga <istvan_v@mailbox.hu>
Cc: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/media/video/cx88/cx88-dvb.c b/drivers/media/video/cx88/cx88-dvb.c
index cf3d33ab541b..396149824fcd 100644
--- a/drivers/media/video/cx88/cx88-dvb.c
+++ b/drivers/media/video/cx88/cx88-dvb.c
@@ -954,6 +954,7 @@ static int dvb_register(struct cx8802_dev *dev)
         struct cx88_core *core = dev->core;
         struct videobuf_dvb_frontend *fe0, *fe1 = NULL;
         int mfe_shared = 0; /* bus not shared by default */
+        int res = -EINVAL;
 
         if (0 != core->i2c_rc) {
                 printk(KERN_ERR "%s/2: no i2c-bus available, cannot attach dvb drivers\n", core->name);
@@ -1566,13 +1567,16 @@ static int dvb_register(struct cx8802_dev *dev)
         call_all(core, core, s_power, 0);
 
         /* register everything */
-        return videobuf_dvb_register_bus(&dev->frontends, THIS_MODULE, dev,
-                                         &dev->pci->dev, adapter_nr, mfe_shared, NULL);
+        res = videobuf_dvb_register_bus(&dev->frontends, THIS_MODULE, dev,
+                &dev->pci->dev, adapter_nr, mfe_shared, NULL);
+        if (res)
+                goto frontend_detach;
+        return res;
 
 frontend_detach:
         core->gate_ctrl = NULL;
         videobuf_dvb_dealloc_frontends(&dev->frontends);
-        return -EINVAL;
+        return res;
 }
 
 /* ----------------------------------------------------------- */