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[01/46,media] dmxdev: don't use before checking file->private_data

Message ID 313ddec45cf1a7b3778eaa9fd3acb31f994b2e88.1409775488.git.m.chehab@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mauro Carvalho Chehab Sept. 3, 2014, 8:27 p.m. UTC 
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 if dmxdevfilter exists before using it.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff mbox

Patch

diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index 42b5e70d5ca7..abff803ad69a 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -1085,10 +1085,9 @@  static long dvb_demux_ioctl(struct file *file, unsigned int cmd,
 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);