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=-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=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 94F78C6377C for ; Mon, 19 Jul 2021 16:26:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80F06613DF for ; Mon, 19 Jul 2021 16:26:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350265AbhGSPpq (ORCPT ); Mon, 19 Jul 2021 11:45:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:52506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344267AbhGSO7c (ORCPT ); Mon, 19 Jul 2021 10:59:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4FD0B61002; Mon, 19 Jul 2021 15:39:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709165; bh=dmoVFB9WV8nDf/ZrKMj21XqmZ8SkQGHGeuBLktOpNMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=thFyBgxMaF0Ci2m4v4xT+vn2nEAoWUgGu0e3H1QW89ncN62pM55iHBqRwFXgrnGgd ZOzVXhgaHabDvfsHNrK9nFuNpjtpyU+vNxXsMRd3v0iFqTZCtXRCQ/XArFML3g50gk bBK8bxs7gQNTb+ixk9Q4SuajQ7LsUXoFjSmFL39k= 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 4.19 277/421] sctp: add size validation when walking chunks Date: Mon, 19 Jul 2021 16:51:28 +0200 Message-Id: <20210719144955.949115171@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@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 e17c8359571c..203aaefd8d04 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -1204,7 +1204,7 @@ 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