Re: [media-dvb-usb-v2] question about value overwrite

From: Malcolm Priestley
Date: Thu May 18 2017 - 15:55:35 EST


Hi

On 18/05/17 20:09, Gustavo A. R. Silva wrote:

Hello everybody,

While looking into Coverity ID 1226934 I ran into the following piece of code at drivers/media/usb/dvb-usb-v2/lmedm04.c:205

205static int lme2510_stream_restart(struct dvb_usb_device *d)
206{
207 struct lme2510_state *st = d->priv;
208 u8 all_pids[] = LME_ALL_PIDS;
209 u8 stream_on[] = LME_ST_ON_W;
210 int ret;
211 u8 rbuff[1];
212 if (st->pid_off)
213 ret = lme2510_usb_talk(d, all_pids, sizeof(all_pids),
214 rbuff, sizeof(rbuff));
215 /*Restart Stream Command*/
216 ret = lme2510_usb_talk(d, stream_on, sizeof(stream_on),
217 rbuff, sizeof(rbuff));
218 return ret;
219}

It is a mistake it should have been ORed ad in |= as lme2510_usb_talk only returns three states.

So if an error is in the running it will be returned to user.

The first of your patches is better and more or less the same, the second would break driver, restart is not an else condition.

Regards


Malcolm