| Message ID | 20250421030020.3108405-2-zhenglifeng1@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/4] PM / devfreq: governor: Replace sscanf() with kstrtoul() in set_freq_store() | expand |
On Mon, 21 Apr 2025 11:00:17 +0800 Lifeng Zheng <zhenglifeng1@huawei.com> wrote: > Replace sscanf() with kstrtoul() in set_freq_store() and check the result > to avoid invalid input. Isn't this a UAPI change? The sscanf() version will ignore trailing characters. In this case it is actually likely that value might have a trailing "Hz". David > > Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> > --- > drivers/devfreq/governor_userspace.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c > index d1aa6806b683..175de0c0b50e 100644 > --- a/drivers/devfreq/governor_userspace.c > +++ b/drivers/devfreq/governor_userspace.c > @@ -9,6 +9,7 @@ > #include <linux/slab.h> > #include <linux/device.h> > #include <linux/devfreq.h> > +#include <linux/kstrtox.h> > #include <linux/pm.h> > #include <linux/mutex.h> > #include <linux/module.h> > @@ -39,10 +40,13 @@ static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr, > unsigned long wanted; > int err = 0; > > + err = kstrtoul(buf, 0, &wanted); > + if (err) > + return err; > + > mutex_lock(&devfreq->lock); > data = devfreq->governor_data; > > - sscanf(buf, "%lu", &wanted); > data->user_frequency = wanted; > data->valid = true; > err = update_devfreq(devfreq);
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c index d1aa6806b683..175de0c0b50e 100644 --- a/drivers/devfreq/governor_userspace.c +++ b/drivers/devfreq/governor_userspace.c @@ -9,6 +9,7 @@ #include <linux/slab.h> #include <linux/device.h> #include <linux/devfreq.h> +#include <linux/kstrtox.h> #include <linux/pm.h> #include <linux/mutex.h> #include <linux/module.h> @@ -39,10 +40,13 @@ static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr, unsigned long wanted; int err = 0; + err = kstrtoul(buf, 0, &wanted); + if (err) + return err; + mutex_lock(&devfreq->lock); data = devfreq->governor_data; - sscanf(buf, "%lu", &wanted); data->user_frequency = wanted; data->valid = true; err = update_devfreq(devfreq);
Replace sscanf() with kstrtoul() in set_freq_store() and check the result to avoid invalid input. Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> --- drivers/devfreq/governor_userspace.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)