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 C5FECC11F66 for ; Tue, 6 Jul 2021 12:25:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB8546223C for ; Tue, 6 Jul 2021 12:25:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242730AbhGFM1f (ORCPT ); Tue, 6 Jul 2021 08:27:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:42406 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235850AbhGFLa3 (ORCPT ); Tue, 6 Jul 2021 07:30:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D7DB561DEC; Tue, 6 Jul 2021 11:21:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625570517; bh=tMnwuOqsKetrJOZHCxfof29wQdNfyrd0hr/fLSioJSQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ie96NERXhG/C3PNMDHLmI3f4kgWDRYoj3KpLfzkl4bwyI+tD2KQxU98RG/bY2a+vN XAD7QfYcUld9ryoCuLFOPXepq0UzyxzzUtlfScRA5ciNgYynkRY/UKOlAGjr7Pygih RPvS56zu5oVEglm3tf9yBynhciZSC1LxC3QQLH+yVDVY2cLF1C4g8D0FXRrj0DHq64 Ne/FWgI4OUXk6bo8OXQROoCJtM7YWcNiKdbLb5CWnq/BEb9It8IaWIYugd7AFqU0Q+ W1FeLmeCmh0AAFHPdVKlesOX/DoZ3pwJj3cleg4fqqheusb6PweCmq+bY3G/71FT5P lntjgH/ZRxaMg== 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 5.12 157/160] sctp: add size validation when walking chunks Date: Tue, 6 Jul 2021 07:18:23 -0400 Message-Id: <20210706111827.2060499-157-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210706111827.2060499-1-sashal@kernel.org> References: <20210706111827.2060499-1-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 8924e2e142c8..f72bff93745c 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