From patchwork Mon Jul 19 14:51:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 481087 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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 DD2D9C07E95 for ; Mon, 19 Jul 2021 15:33:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA88961370 for ; Mon, 19 Jul 2021 15:33:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244815AbhGSOxN (ORCPT ); Mon, 19 Jul 2021 10:53:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:60454 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237751AbhGSOoY (ORCPT ); Mon, 19 Jul 2021 10:44:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9ABD76121F; Mon, 19 Jul 2021 15:22:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626708153; bh=XUwDBV44ClTF8/YLsdYrF24Rh0dJD/re0h0QpAYYk6Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q5DVHWyvNgFZVhFwZ6DkZgQKRwD9Noh6lYzy9qIUo+xHsPEzl4LOL0Q4GIGvLVMAz NvN6twcpC+IC9dO0pBHYkSPpji1+G5VEMU8PoO5XbsLZs7ss1c7WFJkW+vTj8kAeZP VoZ8bPeMt5AT2IgqGkOvqp2nmHVuJhMkfxHhghOQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilja Van Sprundel , Marcelo Ricardo Leitner , "David S. Miller" , Sasha Levin Subject: [PATCH 4.14 201/315] sctp: add size validation when walking chunks Date: Mon, 19 Jul 2021 16:51:30 +0200 Message-Id: <20210719144950.038069549@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144942.861561397@linuxfoundation.org> References: <20210719144942.861561397@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marcelo Ricardo Leitner [ Upstream commit 50619dbf8db77e98d821d615af4f634d08e22698 ] The first chunk in a packet is ensured to be present at the beginning of sctp_rcv(), as a packet needs to have at least 1 chunk. But the second one, may not be completely available and ch->length can be over uninitialized memory. Fix here is by only trying to walk on the next chunk if there is enough to hold at least the header, and then proceed with the ch->length validation that is already there. Reported-by: Ilja Van Sprundel Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sctp/input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sctp/input.c b/net/sctp/input.c index 7380f0a5949b..1af35b69e99e 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -1197,7 +1197,7 @@ static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, ch = (struct sctp_chunkhdr *)ch_end; chunk_num++; - } while (ch_end < skb_tail_pointer(skb)); + } while (ch_end + sizeof(*ch) < skb_tail_pointer(skb)); return asoc; }