Re: [TECH TOPIC] Improving resource ownership and life-time in linux device drivers

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Thu, Aug 10, 2023 at 05:47:02PM +0200, Greg KH wrote:
> On Wed, Aug 09, 2023 at 08:04:39PM +0200, Bartosz Golaszewski wrote:
> > Hi!
> > 
> > I submitted this proposal on time using the website but forgot about
> > sending it here too. Hope that's alright. The abstract follows.
> > 
> > Bartosz Golaszewski
> > 
> > --
> > 
> > Recently there have been several talks about issues with object
> > ownership in device drivers, use-after-free bugs and problems with
> > handling hot unplug events in certain subsystems.
> > 
> > First Laurent Pinchart revisited an older discussion about the harmful
> > side-effects of devres helpers during LPC 2022[1]. I then went down
> > that rabbit hole only to discover a whole suite of issues, not really
> > linked to devres in any way but rather mostly caused by the way
> > subsystems and drivers mix reference counted resources with regular
> > ones[2]. This year Wolfram Sang continued the research and presented
> > even more vulnerable subsystems as well as some potential remedies
> > during his talk at the EOSS 2023 in Prague[3].
> > 
> > I have since experimented with several approaches and would like to
> > present some updates on this subject. During this talk I plan to jump
> > straight into presenting concrete ideas and timelines for improving
> > the driver model and introducing some unification in the way
> > subsystems handle driver data. While this is a significant effort
> > spanning multiple device subsystems that will need to be carried out
> > in many phases over what will most likely be years, without addressing
> > the problems, we'll be left with many parts of the kernel not being
> > able to correctly handle simple driver unbinds.
> 
> I'm all for this, we need some major work in this area.

Likewise. I will however not be physically present at the kernel summit
this year, but plan to participate remotely.

-- 
Regards,

Laurent Pinchart