From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 527D5C48BE5 for ; Mon, 21 Jun 2021 16:40:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 394CE6109E for ; Mon, 21 Jun 2021 16:40:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232321AbhFUQmW (ORCPT ); Mon, 21 Jun 2021 12:42:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:56052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232543AbhFUQhp (ORCPT ); Mon, 21 Jun 2021 12:37:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 149476109E; Mon, 21 Jun 2021 16:29:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1624292944; bh=h3p6fCphVg8BPrbmBoXlbiuTmtHMC8+TL0sU66kDgf4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2nLJz37FbRrA/NPDjsvO3sLENTCHZUBsekcwja1uxGEfK/iYk0qvh59iCzHbTyejL 3L8nmgWEb0qs1qwIlQEdg3ocaxAfy2tAFCWNouMGrbyxtzsM/a23NF7dZEUEVjZsoh 6Hj/Vi3RSIY3yxfNl/iC0btOQ7y66hX65NGc+FDg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Young Xiao <92siuyang@gmail.com>, Maxim Mikityanskiy , Mat Martineau , "David S. Miller" , Sasha Levin Subject: [PATCH 5.12 042/178] mptcp: Fix out of bounds when parsing TCP options Date: Mon, 21 Jun 2021 18:14:16 +0200 Message-Id: <20210621154923.590934946@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210621154921.212599475@linuxfoundation.org> References: <20210621154921.212599475@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maxim Mikityanskiy [ Upstream commit 07718be265680dcf496347d475ce1a5442f55ad7 ] The TCP option parser in mptcp (mptcp_get_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options."). Cc: Young Xiao <92siuyang@gmail.com> Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections") Signed-off-by: Maxim Mikityanskiy Reviewed-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/mptcp/options.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 8848a9e2a95b..47d90cf31f12 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -337,6 +337,8 @@ void mptcp_get_options(const struct sk_buff *skb, length--; continue; default: + if (length < 2) + return; opsize = *ptr++; if (opsize < 2) /* "silly options" */ return; -- 2.30.2