[media] dmxdev: don't use before checking file->private_data
As reported by smatch:
drivers/media/dvb-core/dmxdev.c:1091 dvb_demux_poll() warn: variable dereferenced before check 'dmxdevfilter' (see line 1088)
This was introduced by changeset d102cac8097c.
We need to test before using it.
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index 42b5e70..abff803 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -1085,10 +1085,9 @@
static unsigned int dvb_demux_poll(struct file *file, poll_table *wait)
{
struct dmxdev_filter *dmxdevfilter = file->private_data;
- struct dmxdev *dmxdev = dmxdevfilter->dev;
unsigned int mask = 0;
- if ((!dmxdevfilter) || (dmxdev->exit))
+ if ((!dmxdevfilter) || dmxdevfilter->dev->exit)
return POLLERR;
poll_wait(file, &dmxdevfilter->buffer.queue, wait);