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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 04BEEC433DF for ; Thu, 30 Jul 2020 08:14:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0F452075F for ; Thu, 30 Jul 2020 08:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596096843; bh=4BqZ/RhG1SD/WQbc4OLwfRvW43zToqd/adGssxo8Ef4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vIgs+8LgJN7MKrGu2AVKZLCJUU3ofpMM0tHWFCXeM1eK4Z/oh2BxigPfpp7RlTwsP VAvUlzAc/PSfDMs7MUEZNP8q5KgQuHoExT+Ybog9GM5mNAV+VTcKqP6hl6P3eTLFju jfi9/rpbribUWoGVaWOeqijKzn1BieSqzIkd7JlA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730142AbgG3IN6 (ORCPT ); Thu, 30 Jul 2020 04:13:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:52494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730108AbgG3INE (ORCPT ); Thu, 30 Jul 2020 04:13:04 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3A6122070B; Thu, 30 Jul 2020 08:13:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596096783; bh=4BqZ/RhG1SD/WQbc4OLwfRvW43zToqd/adGssxo8Ef4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qAY20vQwinxZcskcVtIa8NjAb/BRw5V2kEKkXcz9NHkTf3ZHMUcWRsrXS//DWNmpg ABxcOi/0KvlzvZNf0RKpTnFcR+qVxNtLWnT2oa65pbA2ZSOr9ZtfXcRGpxumuyKNVt X8LFXZnCdq2Y2QvuLty6XA/PCEh6DtTP7ks5MVTc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peilin Ye , "David S. Miller" Subject: [PATCH 4.4 39/54] AX.25: Prevent out-of-bounds read in ax25_sendmsg() Date: Thu, 30 Jul 2020 10:05:18 +0200 Message-Id: <20200730074423.084112225@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200730074421.203879987@linuxfoundation.org> References: <20200730074421.203879987@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peilin Ye [ Upstream commit 8885bb0621f01a6c82be60a91e5fc0f6e2f71186 ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ax25/af_ax25.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -1512,7 +1512,8 @@ static int ax25_sendmsg(struct socket *s struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)usax; /* Valid number of digipeaters ? */ - if (usax->sax25_ndigis < 1 || usax->sax25_ndigis > AX25_MAX_DIGIS) { + if (usax->sax25_ndigis < 1 || addr_len < sizeof(struct sockaddr_ax25) + + sizeof(ax25_address) * usax->sax25_ndigis) { err = -EINVAL; goto out; }