From patchwork Thu May 20 09:22:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 444391 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=-19.1 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 35A46C433B4 for ; Thu, 20 May 2021 10:09:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 195AE61444 for ; Thu, 20 May 2021 10:09:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235222AbhETKKp (ORCPT ); Thu, 20 May 2021 06:10:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:42254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235812AbhETKJZ (ORCPT ); Thu, 20 May 2021 06:09:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2666F6143D; Thu, 20 May 2021 09:42:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503740; bh=bIpcaK3P6O0ixzV5ghQ2/4F0iAIThjp71apwk6nJL28=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LOYkgP5k7ILEEgSWZ+oVWwaqP89AE52uXabPBZDSkuAtts2zWfyeZSkHPotdE4zYn fSNRBYklXevzQ75LMlhEwL3TkIFhrEH+blcVhhUTQoXOeRvWvfbxr09k+oiv7xVW9r 5CRFTvfpZ/6kbdroBZ3koxHckNYPeclPd2m0zh/Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.19 357/425] netfilter: nfnetlink_osf: Fix a missing skb_header_pointer() NULL check Date: Thu, 20 May 2021 11:22:06 +0200 Message-Id: <20210520092143.142249257@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pablo Neira Ayuso [ Upstream commit 5e024c325406470d1165a09c6feaf8ec897936be ] Do not assume that the tcph->doff field is correct when parsing for TCP options, skb_header_pointer() might fail to fetch these bits. Fixes: 11eeef41d5f6 ("netfilter: passive OS fingerprint xtables match") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nfnetlink_osf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nfnetlink_osf.c b/net/netfilter/nfnetlink_osf.c index 131f9f8c0b09..917f06110c82 100644 --- a/net/netfilter/nfnetlink_osf.c +++ b/net/netfilter/nfnetlink_osf.c @@ -191,6 +191,8 @@ static const struct tcphdr *nf_osf_hdr_ctx_init(struct nf_osf_hdr_ctx *ctx, ctx->optp = skb_header_pointer(skb, ip_hdrlen(skb) + sizeof(struct tcphdr), ctx->optsize, opts); + if (!ctx->optp) + return NULL; } return tcp;