2020-12-10 15:11:18

by Greg Kroah-Hartman

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

On Thu, Dec 10, 2020 at 03:38:44PM +0100, Greg Kroah-Hartman wrote:
> 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
> > <[email protected]> wrote:
> > >
> > > From: Eric Dumazet <[email protected]>
> > >
> > > 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...

What is the git id of the revert? This ended up already in 4.19.y,
5.4.y, and 5.9.y so needs to be reverted there.

thanks,

greg k-h


2020-12-10 15:15:46

by Eric Dumazet

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

On Thu, Dec 10, 2020 at 3:40 PM Greg Kroah-Hartman
<[email protected]> wrote:
>
> On Thu, Dec 10, 2020 at 03:38:44PM +0100, Greg Kroah-Hartman wrote:
> > 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
> > > <[email protected]> wrote:
> > > >
> > > > From: Eric Dumazet <[email protected]>
> > > >
> > > > 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...
>
> What is the git id of the revert? This ended up already in 4.19.y,
> 5.4.y, and 5.9.y so needs to be reverted there.
>

https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=c02bd115b1d25931159f89c7d9bf47a30f5d4b41

Thanks !

> thanks,
>
> greg k-h

2020-12-10 15:39:42

by Greg Kroah-Hartman

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

On Thu, Dec 10, 2020 at 03:53:09PM +0100, Eric Dumazet wrote:
> On Thu, Dec 10, 2020 at 3:40 PM Greg Kroah-Hartman
> <[email protected]> wrote:
> >
> > On Thu, Dec 10, 2020 at 03:38:44PM +0100, Greg Kroah-Hartman wrote:
> > > 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
> > > > <[email protected]> wrote:
> > > > >
> > > > > From: Eric Dumazet <[email protected]>
> > > > >
> > > > > 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...
> >
> > What is the git id of the revert? This ended up already in 4.19.y,
> > 5.4.y, and 5.9.y so needs to be reverted there.
> >
>
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=c02bd115b1d25931159f89c7d9bf47a30f5d4b41

Thanks, I'll drop the patch from 4.4, 4.9, and 4.14, and queue up this
revert for the other trees now.

greg k-h