From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE64D2C9D for ; Mon, 6 Dec 2021 18:47:48 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10190"; a="217404920" X-IronPort-AV: E=Sophos;i="5.87,292,1631602800"; d="scan'208";a="217404920" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Dec 2021 10:47:48 -0800 X-IronPort-AV: E=Sophos;i="5.87,292,1631602800"; d="scan'208";a="461947381" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2) ([10.251.18.10]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Dec 2021 10:47:48 -0800 Date: Mon, 6 Dec 2021 10:47:47 -0800 (PST) From: Mat Martineau To: Matthieu Baerts cc: Florian Westphal , mptcp@lists.linux.dev Subject: Re: [PATCH mptcp] mptcp: remove tcp ulp setsockopt support In-Reply-To: <61ea8986-10c2-1d4f-6c35-2c910dbdcf89@tessares.net> Message-ID: <38c041f7-29d9-e61d-d5bf-6523785ce12@linux.intel.com> References: <00000000000040972505d24e88e3@google.com> <20211205192700.25396-1-fw@strlen.de> <61ea8986-10c2-1d4f-6c35-2c910dbdcf89@tessares.net> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII On Mon, 6 Dec 2021, Matthieu Baerts wrote: > Hi Florian, > > (without netdev and syzbot ML) > > On 05/12/2021 20:27, 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: >> >> 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. > > Good catch! > Indeed, it doesn't make sense to support TCP_ULP. > >> Reported-by: syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com >> Signed-off-by: Florian Westphal > > I guess we need a Fixes tag here: > > Fixes: d9e4c1291810 ("mptcp: only admit explicitly supported sockopt") > Thanks Florian. Matthieu, could you apply this to the export branch with your suggested Fixes tag? Reviewed-by: Mat Martineau -- Mat Martineau Intel