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=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 AA7BAC11F67 for ; Tue, 6 Jul 2021 12:02:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95579620DC for ; Tue, 6 Jul 2021 12:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241691AbhGFMBZ (ORCPT ); Tue, 6 Jul 2021 08:01:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:47572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237452AbhGFLgK (ORCPT ); Tue, 6 Jul 2021 07:36:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 40BD561C68; Tue, 6 Jul 2021 11:27:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625570867; bh=dmoVFB9WV8nDf/ZrKMj21XqmZ8SkQGHGeuBLktOpNMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vKxhHwaOslHVf96/IEnQMwNAvpuV7JH78UC11un47jNdHyuthO2oQAtpobqLc8d2T yGwuyB7+BD885t0HfLvB0RUXzJ7MCQMGEItvQmcYVpXjMXsZusvJM8JQQKeesSzDJj Qc+/SiD976J+mgsDt+th1erQlhLqGm7qF2VBJLbiQ1oINnHlCdJi5V/GGkKyxCWAQC vh1gS9t9MIQFprtPMgyAIurwHyabKLxfTIqqIP0P2cN0k3IjLBHHyLgClabqYWCXxy zsMaCTBdZS+4bRVlX6ynXHFbMXtTALq2RW40y1WIMx6xctzwBH/ewDt26NjFPN8ATP nTJ+fpWmvZCfQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marcelo Ricardo Leitner , Ilja Van Sprundel , "David S . Miller" , Sasha Levin , linux-sctp@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 54/55] sctp: add size validation when walking chunks Date: Tue, 6 Jul 2021 07:26:37 -0400 Message-Id: <20210706112638.2065023-54-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210706112638.2065023-1-sashal@kernel.org> References: <20210706112638.2065023-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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