From patchwork Mon Jul 19 14:51:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 481309 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 D4FDCC636C9 for ; Mon, 19 Jul 2021 15:12:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C11096120D for ; Mon, 19 Jul 2021 15:12:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245307AbhGSObu (ORCPT ); Mon, 19 Jul 2021 10:31:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:40236 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244634AbhGSO3y (ORCPT ); Mon, 19 Jul 2021 10:29:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3E5986113C; Mon, 19 Jul 2021 15:10:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626707418; bh=FQQIFpnAiR23hT4T3lXEcnFdqObycTksY+X948lJ45A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BGZYjLOdY7O9XXnX5I8FSIu8nvLtmdFDg+is4pZ0XinJiNCudhH5Y/dVLTFGTHxqG HNfN0S2pc6XAlbJeuiP639I26RngngjWt/dmV3Pxoj5z7/MFYvV6lqGugzV+9EdOSc TKjZMIX2YZp51QqfboELrJv0ZhTxtfBnlXrDYTFA= 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 4.9 156/245] sctp: add size validation when walking chunks Date: Mon, 19 Jul 2021 16:51:38 +0200 Message-Id: <20210719144945.448079004@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144940.288257948@linuxfoundation.org> References: <20210719144940.288257948@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 12d821ea8a1f..8f4574c4aa6c 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -1165,7 +1165,7 @@ static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, ch = (sctp_chunkhdr_t *) ch_end; chunk_num++; - } while (ch_end < skb_tail_pointer(skb)); + } while (ch_end + sizeof(*ch) < skb_tail_pointer(skb)); return asoc; }