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 757E0C11F6E for ; Tue, 6 Jul 2021 12:01:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F4D0620DD for ; Tue, 6 Jul 2021 12:01:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240286AbhGFMAe (ORCPT ); Tue, 6 Jul 2021 08:00:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:47602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237284AbhGFLgE (ORCPT ); Tue, 6 Jul 2021 07:36:04 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3BA3161EEA; Tue, 6 Jul 2021 11:26:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625570795; bh=CFfpxMYRtSFEtrkuK4v7XIcMIQZy/kBrY4eH87LdzPY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EBqut+ZhLCiM7flRa7O5b3NUmdkuJfEWccD3qDeoURfqLCJ0tGmpVcihrOrLZ+IRY I+zu8pWJP6OSIvEm/mgNEZLJAsjLYJ3E6oOY7FJXmie+QXvtiJk79URMhbeN0TROI5 yHjKu5SqUAxufPbEzyVZvjb8jRmmzOvOz/MlY2LW0sRAlsve1MYpI1JgfJnuhIZUex Rb3yaeUaIQwxvNZMv3LRTq6lHrY/Tc8wlrlCorm8prbynzYh/axqnf0gXfPXirJoKk RY4dcdI8ucLaM4EMDrHGquPorDcsDuIR76E0/SC7AMtu+OLABGj2QcdSN/+ol1sV8Z 1oxw4VnHsEuRQ== 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 5.4 72/74] sctp: add size validation when walking chunks Date: Tue, 6 Jul 2021 07:25:00 -0400 Message-Id: <20210706112502.2064236-72-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210706112502.2064236-1-sashal@kernel.org> References: <20210706112502.2064236-1-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 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