Re: [PATCH] USB: input: powermate: fix oops with malicious USB descriptors

[Greg Kroah-Hartman]

On Mon, Mar 14, 2016 at 12:46:26PM -0400, Josh Boyer wrote:
> On Mon, Mar 14, 2016 at 12:15 PM, Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Mon, Mar 14, 2016 at 10:12:53AM -0400, Josh Boyer wrote:
> >> The powermate driver expects at least one valid USB endpoint in its
> >> probe function.  If given malicious descriptors that specify 0 for
> >> the number of endpoints, it will crash.  Validate the number of
> >> endpoints on the interface before using them.
> >>
> >> The full report for this issue can be found here:
> >> http://seclists.org/bugtraq/2016/Mar/85
> >>
> >> Reported-by: Ralf Spenneberg <ralf@xxxxxxxxxxxxxx>
> >> Cc: stable <stable@xxxxxxxxxxxxxxx>
> >> Signed-off-by: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx>
> >> ---
> >>  drivers/input/misc/powermate.c | 3 +++
> >>  1 file changed, 3 insertions(+)
> >
> > I'll queue these up after 4.6-rc1 is out as the merge window is closed
> > right now, but we might want to think about a better way to handle this
> > type of thing in the USB core.  A way to keep from having to add checks
> > like this for every single driver, when the driver shouldn't even really
> > have their probe function called unless their expected endpoints are
> > going to be there.
> 
> I thought this discussion came up a while ago, when something very
> similar was fixed in the whiteheat driver (commit cbb4be652d374).  I
> can't find the thread at the moment, but I thought someone said this
> had to be per-driver for some reason.  I'm more than happy to have a
> core subsystem fix if it's possible.
> 
> > I'll think about that over the next few weeks...
> 
> I have something around 8 drivers with issues like this.  I think
> Oliver (now CC'd) is working from the same set of bugs.  Should we
> hold off on submitting individual fixes until later, or should we go
> ahead and submit them?

Please submit them, that will give us a framework to be able to figure
out the specifics of what needs to be changed.

thanks,

greg k-h