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 1FB65C433EF for ; Sun, 5 Dec 2021 19:27:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237937AbhLETbK (ORCPT ); Sun, 5 Dec 2021 14:31:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232951AbhLETbJ (ORCPT ); Sun, 5 Dec 2021 14:31:09 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58418C061714; Sun, 5 Dec 2021 11:27:42 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1mtxAg-0004BD-L7; Sun, 05 Dec 2021 20:27:38 +0100 From: Florian Westphal To: Cc: syzkaller-bugs@googlegroups.com, , linux-kernel@vger.kernel.org, Florian Westphal , syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com Subject: [PATCH mptcp] mptcp: remove tcp ulp setsockopt support Date: Sun, 5 Dec 2021 20:27:00 +0100 Message-Id: <20211205192700.25396-1-fw@strlen.de> X-Mailer: git-send-email 2.32.0 In-Reply-To: <00000000000040972505d24e88e3@google.com> References: <00000000000040972505d24e88e3@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Reported-by: syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com Signed-off-by: Florian Westphal --- diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 3c3db22fd36a..aa3fcd86dbe2 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -543,7 +543,6 @@ static bool mptcp_supported_sockopt(int level, int optname) case TCP_NODELAY: case TCP_THIN_LINEAR_TIMEOUTS: case TCP_CONGESTION: - case TCP_ULP: case TCP_CORK: case TCP_KEEPIDLE: case TCP_KEEPINTVL: -- 2.32.0