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=-19.4 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=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 7D2EEC636C8 for ; Thu, 15 Jul 2021 18:44:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6632C613C9 for ; Thu, 15 Jul 2021 18:44:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236135AbhGOSrR (ORCPT ); Thu, 15 Jul 2021 14:47:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:47558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237977AbhGOSqW (ORCPT ); Thu, 15 Jul 2021 14:46:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7A7B1613CA; Thu, 15 Jul 2021 18:43:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626374608; bh=CFfpxMYRtSFEtrkuK4v7XIcMIQZy/kBrY4eH87LdzPY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TZ99/b4D2/zGWcVYALtzYS96RGG2Jyhi+QIGTXnVXcopiq+fu1O5h5VGUrZE71xXH /ttRMSwvl5Fu295rQSUNr+WjzOvQ7Zk74LWcyZMcRku1u9BH4m+fyMQ7QJhyrIdGw6 j5bJJ2IzBHjzRpyXJvahWL2OYyY9hZOBWG/gdyLs= 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 5.4 069/122] sctp: add size validation when walking chunks Date: Thu, 15 Jul 2021 20:38:36 +0200 Message-Id: <20210715182507.853408276@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182448.393443551@linuxfoundation.org> References: <20210715182448.393443551@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: 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 a84523284777..ab84ebf1af4a 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -1247,7 +1247,7 @@ 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; } -- 2.30.2