Messages in this thread | | | Date | Thu, 14 Mar 2019 11:04:16 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH 1/4] leds: netdev trigger: use memcpy in device_name_store |
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On Thu, Mar 14, 2019 at 10:57:14AM +0100, Rasmus Villemoes wrote: > On 14/03/2019 10.29, Uwe Kleine-König wrote: > > Hello, > > > > On Wed, Mar 13, 2019 at 09:26:12PM +0100, Rasmus Villemoes wrote: > >> --- a/drivers/leds/trigger/ledtrig-netdev.c > >> +++ b/drivers/leds/trigger/ledtrig-netdev.c > >> @@ -122,7 +122,8 @@ static ssize_t device_name_store(struct device *dev, > >> trigger_data->net_dev = NULL; > >> } > >> > >> - strncpy(trigger_data->device_name, buf, size); > >> + memcpy(trigger_data->device_name, buf, size); > >> + trigger_data->device_name[size] = '\0'; > > > > This is open-coding > > > > strlcpy(trigger_data->device_name, buf, size); > > No. size here is the number of bytes userspace wrote, which never (well, > almost never, they could do something odd) contain a nul byte. Passing > that as size to strlcpy would guarantee that we chopped off the last > character from the user input.
You're right here, strlcpy isn't a replacement here. I withdraw my suggestion.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
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