Re: [PATCH 4.4 15/39] geneve: pull IP header before ECN decapsulation

From: Greg Kroah-Hartman
Date: Thu Dec 10 2020 - 10:41:30 EST


On Thu, Dec 10, 2020 at 03:32:12PM +0100, Eric Dumazet wrote:
> On Thu, Dec 10, 2020 at 3:26 PM Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > From: Eric Dumazet <edumazet@xxxxxxxxxx>
> >
> > IP_ECN_decapsulate() and IP6_ECN_decapsulate() assume
> > IP header is already pulled.
> >
> > geneve does not ensure this yet.
> >
> > Fixing this generically in IP_ECN_decapsulate() and
> > IP6_ECN_decapsulate() is not possible, since callers
> > pass a pointer that might be freed by pskb_may_pull()
> >
> > syzbot reported :
> >
>
> Note that we had to revert this patch, so you can either scratp this
> backport, or make sure to backport the revert.

I'll drop it thanks. Odd I lost the upstream git id on this patch, let
me check what went wrong...

greg k-h