On Fri, Aug 4, 2023 at 5:47 PM Oliver Hartkopp <socketcan@xxxxxxxxxxxx> wrote:
>
>
>
> On 04.08.23 14:12, Eric Dumazet wrote:
> > On Fri, Aug 4, 2023 at 1:28 PM Oliver Hartkopp <socketcan@xxxxxxxxxxxx> wrote:
> >>
> >> Commit ee8b94c8510c ("can: raw: fix receiver memory leak") introduced
> >> a new reference to the CAN netdevice that has assigned CAN filters.
> >> But this new ro->dev reference did not maintain its own refcount which
> >> lead to another KASAN use-after-free splat found by Eric Dumazet.
> >>
> >> This patch ensures a proper refcount for the CAN nedevice.
> >
> > Hi Olivier
> >
> > I would feel a bit safer with new longterm device references if you
> > could add an ro->dev_tracker and use netdev_put() netdev_hold() and
> > friends ;)
> >
> > Thanks !
> >
>
> Hi Eric,
>
> the netdev_hold() mechanic has been introduced in Linux 6.0.
>
> Would it make sense to take this patch as fix for all the current stable
> kernels and move to the dev-tracker as improvement via net-next as usual?
Good question.
My take on this, but others might disagree :
I think it is better to cook a patch for current upstream kernels.
Then we will adapt it when backporting to old ones, it should be
relatively easy.
