Subject: Re: [RFC PATCH net-next 02/12] devlink: Hold a reference on parent device

From: Ido Schimmel <[email-masked]>
Date: Tue, 17 Oct 2023 11:11:24 +0300

On Tue, Oct 17, 2023 at 09:56:18AM +0200, Jiri Pirko wrote:
> Tue, Oct 17, 2023 at 09:42:47AM CEST, [email-masked] wrote:
> >Each devlink instance is associated with a parent device and a pointer
> >to this device is stored in the devlink structure, but devlink does not
> >hold a reference on this device.
> >
> >This is going to be a problem in the next patch where - among other
> >things - devlink will acquire the device lock during netns dismantle,
> >before the reload operation. Since netns dismantle is performed
> >asynchronously and since a reference is not held on the parent device,
> >it will be possible to hit a use-after-free.
> >
> >Prepare for the upcoming change by holding a reference on the parent
> >device.
> >
> 
> Just a note, I'm currently pushing the same patch as a part
> of my patchset:
> https://lore.kernel.org/all/[email-masked]/

Then you probably need patch #1 as well:

https://lore.kernel.org/netdev/[email-masked]/