[PATCH 1/1] media: dvb-usb-v2: ce6230: fix bug when sending usb_control_msg of size 0

[Jakov Novak]

The function ce6230_ctrl_msg, didn't check the size of the message that
was supposed to be read/written, which in turn caused the error at the
usb core function usb_submit_urb after calling usb_control_msg in the
driver code. This patch fixes the issue by returning an error code if
the req->data_len == 0.

Fixes: eebb876b0b8f ("V4L/DVB (11216): Add driver for Intel CE6230 DVB-T USB2.0")
Reported-and-tested-by: syzbot+427909a2e3b2f83d78cb@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=427909a2e3b2f83d78cb
Signed-off-by: Jakov Novak <jakovnovak30@xxxxxxxxx>
---
 drivers/media/usb/dvb-usb-v2/ce6230.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/media/usb/dvb-usb-v2/ce6230.c b/drivers/media/usb/dvb-usb-v2/ce6230.c
index 7ebaf3ee4491..dd3aa45b56a3 100644
--- a/drivers/media/usb/dvb-usb-v2/ce6230.c
+++ b/drivers/media/usb/dvb-usb-v2/ce6230.c
@@ -23,6 +23,13 @@ static int ce6230_ctrl_msg(struct dvb_usb_device *d, struct usb_req *req)
 	value = req->value;
 	index = req->index;
 
+	if (!req->data_len) {
+		dev_err(&d->udev->dev,
+				"%s: cannot send crtl_msg of size 0",
+				KBUILD_MODNAME);
+		return -ENOBUFS;
+	}
+
 	switch (req->cmd) {
 	case I2C_READ:
 	case DEMOD_READ:
-- 
2.53.0