Messages in this thread |  | | From | Pavan Kondeti <> | Date | Tue, 8 Aug 2017 12:26:24 +0530 | Subject | Re: [PATCH] devfreq: add error check for sscanf in userspace governor |
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Hi Santosh,
On Mon, Aug 7, 2017 at 6:36 PM, Santosh Mardi <gsantosh@codeaurora.org> wrote: > store_freq function of devfreq userspace governor > executes further, even if error is returned from sscanf, > this will result in setting up wrong frequency value. > > Add proper error check to bail out if any error is returned. > > Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org> > --- > drivers/devfreq/governor_userspace.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c > index 77028c2..1d0c9cc 100644 > --- a/drivers/devfreq/governor_userspace.c > +++ b/drivers/devfreq/governor_userspace.c > @@ -53,12 +53,15 @@ static ssize_t store_freq(struct device *dev, struct device_attribute *attr, > mutex_lock(&devfreq->lock); > data = devfreq->data; > > - sscanf(buf, "%lu", &wanted); > + err = sscanf(buf, "%lu", &wanted); > + if (err != 1) > + goto out;
You can save this goto statement by moving this sscanf checking to before taking the mutex.
> data->user_frequency = wanted; > data->valid = true; > err = update_devfreq(devfreq); > if (err == 0) > err = count; > +out: > mutex_unlock(&devfreq->lock); > return err; > } > -- > 1.9.1 >
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