Re: [PATCH v1] HID: make arrays usage and value to be the same

[Will McVicker]

On Sat, Dec 05, 2020 at 09:59:57AM +0100, Greg KH wrote:
> On Sat, Dec 05, 2020 at 12:48:48AM +0000, Will McVicker wrote:
> > The HID subsystem allows an "HID report field" to have a different
> > number of "values" and "usages" when it is allocated. When a field
> > struct is created, the size of the usage array is guaranteed to be at
> > least as large as the values array, but it may be larger. This leads to
> > a potential out-of-bounds write in
> > __hidinput_change_resolution_multipliers() and an out-of-bounds read in
> > hidinput_count_leds().
> > 
> > To fix this, let's make sure that both the usage and value arrays are
> > the same size.
> > 
> > Signed-off-by: Will McVicker <willmcvicker@xxxxxxxxxx>
> 
> Any reason not to also add a cc: stable on this?
No reason not to include stable. CC'd here.

> 
> And, has this always been the case, or was this caused by some specific
> commit in the past?  If so, a "Fixes:" tag is always nice to included.
I dug into the history and it's been like this for the past 10 years. So yeah
pretty much always like this.

> 
> And finally, as you have a fix for this already, no need to cc:
> security@k.o as there's nothing the people there can do about it now :)
Is that short for security@xxxxxxxxxx? If yes, then I did include them. If no,
do you mind explaining?

> 
> thanks,
> 
> greg k-h