Re: [PATCH] efi: move some sysfs files to be read-only by root

From: Greg Kroah-Hartman
Date: Wed Dec 06 2017 - 01:30:53 EST


On Wed, Dec 06, 2017 at 07:50:41AM +1100, Tobin C. Harding wrote:
> On Tue, Dec 05, 2017 at 11:13:43AM +0100, Greg Kroah-Hartman wrote:
> > Thanks to the scripts/leaking_addresses.pl script, it was found that
> > some EFI values should not be readable by non-root users.
> >
> > So make them root-only, and to do that, add a __ATTR_RO_MODE() macro to
> > make this easier, and use it in other places at the same time.
> >
> > Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Tested-by: Dave Young <dyoung@xxxxxxxxxx>
> > Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
> > Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> > Cc: stable <stable@xxxxxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >
> > ---
> > drivers/firmware/efi/efi.c | 3 +--
> > drivers/firmware/efi/esrt.c | 15 ++++++---------
> > drivers/firmware/efi/runtime-map.c | 10 +++++-----
> > include/linux/sysfs.h | 5 +++++
> > 4 files changed, 17 insertions(+), 16 deletions(-)
> >
> > --- a/drivers/firmware/efi/efi.c
> > +++ b/drivers/firmware/efi/efi.c
> > @@ -143,8 +143,7 @@ static ssize_t systab_show(struct kobjec
> > return str - buf;
> > }
>
> Greg, do you add the CC's here in the commit log for a technical reason?
> Is it so that future investigation that leads to this commit can see who
> to involve in any further discussion?

They came from the output of scripts/get_maintainer.pl on who I should
be sending the patch to, and who should hopefully review it.

> As an example, for the patch that added the %p hashing should I have
> CC'd Jason A. Donenfeld since he was the brains behind the SipHash
> stuff and gave loads of suggestions/direction?

If you want to. It's also a good way for me to track who the patch gets
sent to when doing multiple versions of a patch series. git send-email
picks those up and sends the patch to them as well, making it easier on
the developer instead of having to remember a long --cc= list of
addresses.

thanks,

greg k-h