Re: [PATCH 4.4 24/28] can: dev: prevent potential information leak in can_fill_info()

[Dan Carpenter]

On Tue, Feb 02, 2021 at 07:53:17PM +0100, Pavel Machek wrote:
> Hi!
> 
> > From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > 
> > [ Upstream commit b552766c872f5b0d90323b24e4c9e8fa67486dd5 ]
> > 
> > The "bec" struct isn't necessarily always initialized. For example, the
> > mcp251xfd_get_berr_counter() function doesn't initialize anything if the
> > interface is down.
> 
> Well, yes... and = {} does not neccessarily initialize all of the
> structure... for example padding.
> 
> It is really simple
> 
> struct can_berr_counter {
> 	__u16 txerr;
> 	__u16 rxerr;
> };
> 
> but maybe something like alpha uses padding in such case, and memset
> would be better?

I'm pretty sure nothing uses padding in this situation.  If it does then
we need to re-work a bunch of code.

regards,
dan carpenter