Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94532C433EF for ; Mon, 6 Dec 2021 18:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347338AbhLFSrv (ORCPT ); Mon, 6 Dec 2021 13:47:51 -0500 Received: from mga14.intel.com ([192.55.52.115]:36114 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346257AbhLFSru (ORCPT ); Mon, 6 Dec 2021 13:47:50 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10190"; a="237605152" X-IronPort-AV: E=Sophos;i="5.87,292,1631602800"; d="scan'208";a="237605152" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Dec 2021 10:44:21 -0800 X-IronPort-AV: E=Sophos;i="5.87,292,1631602800"; d="scan'208";a="515086341" Received: from jperiasx-mobl.amr.corp.intel.com (HELO mjmartin-desk2) ([10.251.18.10]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Dec 2021 10:44:21 -0800 Date: Mon, 6 Dec 2021 10:44:16 -0800 (PST) From: Mat Martineau To: Jakub Kicinski cc: Florian Westphal , mptcp@lists.linux.dev, syzkaller-bugs@googlegroups.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com Subject: Re: [PATCH mptcp] mptcp: remove tcp ulp setsockopt support In-Reply-To: <20211206075515.3cf5b0df@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Message-ID: <2297cabb-be69-98ef-f4fc-d9472c7820cc@linux.intel.com> References: <00000000000040972505d24e88e3@google.com> <20211205192700.25396-1-fw@strlen.de> <20211206075326.700f2078@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20211206075515.3cf5b0df@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 6 Dec 2021, Jakub Kicinski wrote: > On Mon, 6 Dec 2021 07:53:26 -0800 Jakub Kicinski wrote: >> On Sun, 5 Dec 2021 20:27:00 +0100 Florian Westphal wrote: >>> TCP_ULP setsockopt cannot be used for mptcp because its already >>> used internally to plumb subflow (tcp) sockets to the mptcp layer. >>> >>> syzbot managed to trigger a crash for mptcp connections that are >>> in fallback mode: >> >> Fallback mode meaning ops are NULL? I'm slightly confused by this >> report. > > Ah, it's the socket not the ops. > >>> KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] >>> CPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0 >>> RIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline] >>> [..] >>> __tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline] >>> tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160 >>> do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391 >>> mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638 >>> >>> Remove support for TCP_ULP setsockopt. >>> >>> Reported-by: syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com >>> Signed-off-by: Florian Westphal Jakub - If you could mark this as "Not Applicable" in netdevbpf patchwork, we'll apply it to the mptcp tree and resubmit to netdev with some related patches. Thanks, -- Mat Martineau Intel