Re: [PATCH 01/11] media: tm6000: fix potential Spectre variant 1

[Mauro Carvalho Chehab]

Em Mon, 14 May 2018 22:31:37 -0500
"Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> escreveu:

> Hi Mauro,
> 
> On 04/26/2018 06:42 PM, Mauro Carvalho Chehab wrote:
> 
> >>
> >> I noticed you changed the status of this series from rejected to new.
> > 
> > Yes.
> > 
> >> Also, there are other similar issues in media/pci/
> > 
> > Well, the issues will be there everywhere on all media drivers.
> > 
> > I marked your patches because I need to study it carefully, after
> > Peter's explanations. My plan is to do it next week. Still not
> > sure if the approach you took is the best one or not.
> > 
> > As I said, one possibility is to change the way v4l2-core handles
> > VIDIOC_ENUM_foo ioctls, but that would be make harder to -stable
> > backports.
> > 
> > I need a weekend to sleep on it.
> > 
> 
> I'm curious about how you finally resolved to handle these issues.
> 
> I noticed Smatch is no longer reporting them.

There was no direct fix for it, but maybe this patch has something
to do with the smatch error report cleanup:

commit 3ad3b7a2ebaefae37a7eafed0779324987ca5e56
Author: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Date:   Tue May 8 13:56:12 2018 -0400

    media: v4l2-ioctl: replace IOCTL_INFO_STD with stub functions
    
    This change removes IOCTL_INFO_STD and adds stub functions where
    needed using the DEFINE_V4L_STUB_FUNC macro. This fixes indirect call
    mismatches with Control-Flow Integrity, caused by calling standard
    ioctls using a function pointer that doesn't match the function type.
    
    Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
    Signed-off-by: Hans Verkuil <hansverk@xxxxxxxxx>
    Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>



> 
> Thanks
> --
> Gustavo



Thanks,
Mauro