From: Dave Watson <davejwatson@fb.com>
Subject: Re: [PATCH v3 net-next 1/4] tcp: ULP infrastructure
Date: Mon, 26 Jun 2017 07:30:19 -0700
Message-ID: <20170626143019.GA6357@davejwatson-mba.dhcp.thefacebook.com>
References: <cover.1497465295.git.davejwatson@fb.com>
 <20170614183714.GA80310@davejwatson-mba.dhcp.thefacebook.com>
 <20170625024258.qoynefxset3cmdla@sasha-lappy>
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Cc: Ilya Lesokhin <ilyal@mellanox.com>,
        Aviad Yehezkel <aviadye@mellanox.com>,
        Boris Pismenny <borisp@mellanox.com>,
        Liran Liss <liranl@mellanox.com>,
        Matan Barak <matanb@mellanox.com>,
        David Miller <davem@davemloft.net>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        Tom Herbert <tom@herbertland.com>,
        "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        Hannes Frederic Sowa <hannes@stressinduktion.org>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        "nmav@gnutls.org" <nmav@gnutls.org>,
        "fridolin.pokorny@gmail.com" <fridolin.pokorny@gmail.com>
To: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
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In-Reply-To: <20170625024258.qoynefxset3cmdla@sasha-lappy>
Sender: linux-crypto-owner@vger.kernel.org

On 06/25/17 02:42 AM, Levin, Alexander (Sasha Levin) wrote:
> On Wed, Jun 14, 2017 at 11:37:14AM -0700, Dave Watson wrote:
> >Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP
> >sockets. Based on a similar infrastructure in tcp_cong.  The idea is that any
> >ULP can add its own logic by changing the TCP proto_ops structure to its own
> >methods.
> >
> >Example usage:
> >
> >setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls"));
> >
> >modules will call:
> >tcp_register_ulp(&tcp_tls_ulp_ops);
> >
> >to register/unregister their ulp, with an init function and name.
> >
> >A list of registered ulps will be returned by tcp_get_available_ulp, which is
> >hooked up to /proc.  Example:
> >
> >$ cat /proc/sys/net/ipv4/tcp_available_ulp
> >tls
> >
> >There is currently no functionality to remove or chain ULPs, but
> >it should be possible to add these in the future if needed.
> >
> >Signed-off-by: Boris Pismenny <borisp@mellanox.com>
> >Signed-off-by: Dave Watson <davejwatson@fb.com>
> 
> Hey Dave,
> 
> I'm seeing the following while fuzzing, which was bisected to this commit:
> 
> ==================================================================
> BUG: KASAN: null-ptr-deref in copy_to_user include/linux/uaccess.h:168 [inline]
> BUG: KASAN: null-ptr-deref in do_tcp_getsockopt.isra.33+0x24f/0x1e30 net/ipv4/tcp.c:3057
> Read of size 4 at addr 0000000000000020 by task syz-executor1/15452

At a glance, this looks like it was fixed already by

https://www.mail-archive.com/netdev@vger.kernel.org/msg175226.html

Can you recheck with that patch, or verify that you already have it?
Thanks.