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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 43AE3C433E1 for ; Thu, 23 Jul 2020 01:07:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B0272080D for ; Thu, 23 Jul 2020 01:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387490AbgGWBHZ (ORCPT ); Wed, 22 Jul 2020 21:07:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728607AbgGWBHY (ORCPT ); Wed, 22 Jul 2020 21:07:24 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9B8BC0619DC; Wed, 22 Jul 2020 18:07:24 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 03364126B39BC; Wed, 22 Jul 2020 17:50:38 -0700 (PDT) Date: Wed, 22 Jul 2020 18:07:23 -0700 (PDT) Message-Id: <20200722.180723.102622644879670834.davem@davemloft.net> To: yepeilin.cs@gmail.com Cc: jreuter@yaina.de, ralf@linux-mips.org, gregkh@linuxfoundation.org, syzkaller-bugs@googlegroups.com, linux-kernel-mentees@lists.linuxfoundation.org, kuba@kernel.org, linux-hams@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [Linux-kernel-mentees] [PATCH net] AX.25: Prevent out-of-bounds read in ax25_sendmsg() From: David Miller In-Reply-To: <20200722160512.370802-1-yepeilin.cs@gmail.com> References: <20200722160512.370802-1-yepeilin.cs@gmail.com> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 22 Jul 2020 17:50:39 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peilin Ye Date: Wed, 22 Jul 2020 12:05:12 -0400 > Checks on `addr_len` and `usax->sax25_ndigis` are insufficient. > ax25_sendmsg() can go out of bounds when `usax->sax25_ndigis` equals to 7 > or 8. Fix it. > > It is safe to remove `usax->sax25_ndigis > AX25_MAX_DIGIS`, since > `addr_len` is guaranteed to be less than or equal to > `sizeof(struct full_sockaddr_ax25)` > > Signed-off-by: Peilin Ye Applied.