[PATCH 5.5 15/23] media: digitv: dont continue if remote control state cant be read

Greg Kroah-Hartman
2020-02-03T16:38:00Z

From: Sean Young <sean@mess.org>

commit eecc70d22ae51225de1ef629c1159f7116476b2e upstream.

This results in an uninitialized variable read.

Reported-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/dvb-usb/digitv.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/media/usb/dvb-usb/digitv.c
+++ b/drivers/media/usb/dvb-usb/digitv.c
@@ -230,18 +230,22 @@ static struct rc_map_table rc_map_digitv

static int digitv_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
{
- int i;
+ int ret, i;
u8 key[5];
u8 b[4] = { 0 };

*event = 0;
*state = REMOTE_NO_KEY_PRESSED;

- digitv_ctrl_msg(d,USB_READ_REMOTE,0,NULL,0,&key[1],4);
+ ret = digitv_ctrl_msg(d, USB_READ_REMOTE, 0, NULL, 0, &key[1], 4);
+ if (ret)
+ return ret;

/* Tell the device we've read the remote. Not sure how necessary
this is, but the Nebula SDK does it. */
- digitv_ctrl_msg(d,USB_WRITE_REMOTE,0,b,4,NULL,0);
+ ret = digitv_ctrl_msg(d, USB_WRITE_REMOTE, 0, b, 4, NULL, 0);
+ if (ret)
+ return ret;

/* if something is inside the buffer, simulate key press */
if (key[1] != 0)