linux-kernel - Re: [PATCH bpf-next] net: Fix slab-out-of-bounds in inet[6]_steal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230809171451.78725-1-kuniyu@amazon.com>
Date:   Wed, 9 Aug 2023 10:14:51 -0700
From:   Kuniyuki Iwashima <kuniyu@...zon.com>
To:     <lmb@...valent.com>
CC:     <bpf@...r.kernel.org>, <daniel@...earbox.net>,
        <davem@...emloft.net>, <edumazet@...gle.com>, <kuba@...nel.org>,
        <kuniyu@...zon.com>, <linux-kernel@...r.kernel.org>,
        <martin.lau@...nel.org>, <martin.lau@...ux.dev>,
        <memxor@...il.com>, <netdev@...r.kernel.org>, <pabeni@...hat.com>
Subject: Re: [PATCH bpf-next] net: Fix slab-out-of-bounds in inet[6]_steal_sock

From: Lorenz Bauer <lmb@...valent.com>
Date: Wed, 9 Aug 2023 17:55:02 +0100
> On Wed, Aug 9, 2023 at 4:56 PM Kuniyuki Iwashima <kuniyu@...zon.com> wrote:
> >
> > > Things we could do if necessary:
> > > 1. Reset the flag in inet_csk_clone_lock like we do for SOCK_RCU_FREE
> >
> > I think we can't do this as sk_reuseport is inherited to twsk and used
> > in inet_bind_conflict().
> 
> Ok, so what kind of state does reuseport carry in the various states then?
> 
> TCP_LISTEN: sk_reuseport && sk_reuseport_cb
> TCP_ESTABLISHED: sk_reuseport && !sk_reuseport_cb
> TCP_TIME_WAIT: sk_reuseport && !sk_reuseport_cb
> 
> Where is sk_reuseport_cb cleared? On clone? Or not at all?

sk_clone_lock() does when cloning sk from listener, and we
cannot check sk_reuseport_cb for twsk as it doesn't have the
member.


> 
> > > 2. Duplicate the cb check into inet[6]_steal_sock
> >
> > or 3. Add sk_fullsock() test ?
> 
> I guess this would be in addition to the convoluted series of checks
> I've removed in this patch?

Yes.