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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 71771C433E2 for ; Tue, 8 Sep 2020 18:20:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F2A4207DE for ; Tue, 8 Sep 2020 18:20:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599589207; bh=l/8H7rVMog7bWzM6uvkGF62iaNWvmch34g7eQFlLRUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GHDpvDJxPdv9z7QUSAox0MdrWVrIJomJAhdUK2D5wO5+VaBzns4QNyjCMGhTOgLnK t7V/Ywgkqg30zsoqBj3ohVTB+wfAnTD5mXYsO1blFmGo9tQZ7HOB382MWZ8S3BFwr9 vWc8RrPvelFDGgtiW6D7SUmCT/Bz4LCt0/AUatW0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731631AbgIHST5 (ORCPT ); Tue, 8 Sep 2020 14:19:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:55394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731467AbgIHQLN (ORCPT ); Tue, 8 Sep 2020 12:11:13 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0176824803; Tue, 8 Sep 2020 15:43:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599579789; bh=l/8H7rVMog7bWzM6uvkGF62iaNWvmch34g7eQFlLRUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yaGFISJpoMFJQpaTy0ySvg3aZtE1x3qKqLPsPji4kdlhor+OIGsFd9A+6Pl9hTmZM CE2DLxaZke5wHoeursRd4RPxYkxS4QpRQUtrH5NDta3FtGcludQjJw189egSkx0Ldm TM+U9XhctIGW/lsMCpkRuxYBfXAsr0anvSaERZ24= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 5.4 034/129] netfilter: nf_tables: fix destination register zeroing Date: Tue, 8 Sep 2020 17:24:35 +0200 Message-Id: <20200908152231.390238249@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152229.689878733@linuxfoundation.org> References: <20200908152229.689878733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Florian Westphal [ Upstream commit 1e105e6afa6c3d32bfb52c00ffa393894a525c27 ] Following bug was reported via irc: nft list ruleset set knock_candidates_ipv4 { type ipv4_addr . inet_service size 65535 elements = { 127.0.0.1 . 123, 127.0.0.1 . 123 } } .. udp dport 123 add @knock_candidates_ipv4 { ip saddr . 123 } udp dport 123 add @knock_candidates_ipv4 { ip saddr . udp dport } It should not have been possible to add a duplicate set entry. After some debugging it turned out that the problem is the immediate value (123) in the second-to-last rule. Concatenations use 32bit registers, i.e. the elements are 8 bytes each, not 6 and it turns out the kernel inserted inet firewall @knock_candidates_ipv4 element 0100007f ffff7b00 : 0 [end] element 0100007f 00007b00 : 0 [end] Note the non-zero upper bits of the first element. It turns out that nft_immediate doesn't zero the destination register, but this is needed when the length isn't a multiple of 4. Furthermore, the zeroing in nft_payload is broken. We can't use [len / 4] = 0 -- if len is a multiple of 4, index is off by one. Skip zeroing in this case and use a conditional instead of (len -1) / 4. Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- include/net/netfilter/nf_tables.h | 2 ++ net/netfilter/nft_payload.c | 4 +++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 2d0275f13bbfd..bc2c73f549622 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -143,6 +143,8 @@ static inline u64 nft_reg_load64(u32 *sreg) static inline void nft_data_copy(u32 *dst, const struct nft_data *src, unsigned int len) { + if (len % NFT_REG32_SIZE) + dst[len / NFT_REG32_SIZE] = 0; memcpy(dst, src, len); } diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 0e3bfbc26e790..62dc728bf93c9 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -79,7 +79,9 @@ void nft_payload_eval(const struct nft_expr *expr, u32 *dest = ®s->data[priv->dreg]; int offset; - dest[priv->len / NFT_REG32_SIZE] = 0; + if (priv->len % NFT_REG32_SIZE) + dest[priv->len / NFT_REG32_SIZE] = 0; + switch (priv->base) { case NFT_PAYLOAD_LL_HEADER: if (!skb_mac_header_was_set(skb)) -- 2.25.1