V4L/DVB (7325): cx88-dvb: fix an OOPS for xc3028 devices, when dvb_attach fails

If dvb_attach fails, dev->dvb.frontend is NULL. This will produce an OOPS, as
reported.

Thanks to Vanessa Ezekowitz <vanessaezekowitz@gmail.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/media/video/cx88/cx88-dvb.c b/drivers/media/video/cx88/cx88-dvb.c
index cf6b9b05f496..d72b817bf886 100644
--- a/drivers/media/video/cx88/cx88-dvb.c
+++ b/drivers/media/video/cx88/cx88-dvb.c
@@ -461,6 +461,13 @@ static int attach_xc3028(u8 addr, struct cx8802_dev *dev)
                 .video_dev = dev->core,
         };
 
+        if (!dev->dvb.frontend) {
+                printk(KERN_ERR "%s/2: dvb frontend not attached. "
+                                "Can't attach xc3028\n",
+                       dev->core->name);
+                return -EINVAL;
+        }
+
         fe = dvb_attach(xc2028_attach, dev->dvb.frontend, &cfg);
         if (!fe) {
                 printk(KERN_ERR "%s/2: xc3028 attach failed\n",