From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792774170; b=jE8E/VZ31EvL4o8I6Xkw//arKBZcbTw2lRF+W7UHVysFz3kLSXaWtSDm1zgjYLqy6IZU euF2KuyIubcoLPFlUCvXQRjiyO+3Gz1ksC1aoq71M4d71hYhN4uWrYGWSasD8d5BGHLM+ bPRCNL5tNmHz15SnggHYnooE+dkTnYScdeKKmGI3o5oDlHoLGZRu0oAkZy6tMwaMFZf/t x6gqjqRQ9yLikiflpC4J7hPIP+ORcEL8nSkgijK91oEWDhBAzl1cxJ44P7WvP3KtpyVj4 6kO82/2JPbXg/k52Bek9YRcz3SiJi0C8p70tjHK/XC+Umz/KwcnfJcIRZ6S2u6QQ8sA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792774170; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=Sz1bVLpiFuKK+RCQYpq7UXkq/LFxamweMzs5zFJlmtA=; b=0eykGQD7lZNDl6m2yybuaXasF2eOhMPo1/pNoRr0WkzPWBNsaA2+YXlMQC/fgviPNRMA IXZmOpJ1+1vIbl4jpOB0GruYrMDAohuHo692BZWsYrWhwwyvCmAdRn/tZVprWURR5WWuy XQukfpzIqqxea+g7LnigdqQfnVOPm9PmSpjkfm+o2x/BSH3nBirvmeXCsT+t61A6r/GCS j0tcHJzC7FVWfRoLcvcJTNOKNOVu+pZK4ATyCiSoSpgqNzcbo/52yZuDXE0+jhFmrUgMe 0TCxkvzdHTSf4P917vEQyomip4IuGiIYiSHP973F6dqTNkuELEbo43g/QQ03+NSwOSA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=ok717qUD; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18DBC606A31B; Fri, 23 Oct 2026 16:49:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=ok717qUD Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FFB51F01825; Fri, 23 Oct 2026 16:49:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792774169; bh=Sz1bVLpiFuKK+RCQYpq7UXkq/LFxamweMzs5zFJlmtA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ok717qUDf6t/fYZukkzCDHtF2PqgAW7H9ho8VDPBdJ16O5QR2CTac76ONsNjQeaRd gnirttLAnYTeyHyNlG8hYeVp3P2T0YvQSvkksYaZP6Hd5XuUiOGS54mBc0VLwQxlnk e5Jickwp87C0UuqckWFUdjeJoFyUeeA3puw51Dhc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michal Kubecek , Florian Westphal , Pablo Neira Ayuso , Sasha Levin , stable+noautosel@kernel.org Subject: [PATCH 6.18 145/193] netfilter: nft_byteorder: remove multi-register support Date: Fri, 23 Oct 2026 18:37:02 +0200 Message-ID: <20261023163717.639412580@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261023163714.201276352@linuxfoundation.org> References: <20261023163714.201276352@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal [ Upstream commit bb061d3de41707415269be75ebf700efb03ec212 ] 64bit byteorder conversion is broken when several registers need to be converted because the source register array advances in steps for 4 bytes instead of 8: for (i = ... src64 = nft_reg_load64(&src[i]); ~~~~~ u32 *src nft_reg_store64(&dst64[i], Remove the multi-register support, it has other issues as well: Pablo points out that commit caf3ef7468f7 ("netfilter: nf_tables: prevent OOB access in nft_byteorder_eval") alters semantics: before the loop operated on registers, i.e. for ( ... ) dst32[i] = htons((u16)src32[i]) .. but after the patch it will operate on bytes, which makes this useless to convert e.g. concatenations, which store each compound in its own register. Multi-convert of u32 has one theoretical application: ct mark . meta mark . tcp dport @intervalset Because ct mark and meta mark are host byte order, use with intervals has to convert the byteorder for ct/meta mark value to network byte order (bigendian). nftables emits this: [ meta load mark => reg 1 ] [ byteorder reg 1 = hton(reg 1, 4, 4) ] [ ct load mark => reg 9 ] [ byteorder reg 9 = hton(reg 9, 4, 4) ] ... I.e. two separate calls. Theoretically it could be changed to do: [ meta load mark => reg 1 ] [ ct load mark => reg 9 ] [ byteorder reg 1 = htonl(reg 1, 4, 8) ] ... But then all it would take to change the set to meta mark . tcp dport . ct mark ... and we'd be back to two "byteorder" calls. IOW, support to convert a range of registers is both dysfunctional and dubious. Simplify this: remove the feature. Pablo Neira Ayuso points out that nftables before 1.1.0 can generate incorrect byteorder conversions, see 9fe58952c45a, "evaluate: skip byteorder conversion for selector smaller than 2 bytes" in nftables.git). Affected rulesets fail to load with this change and old userspace due to 'len != size' check. Fixes: c301f0981fdd ("netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()") Cc: # may break rule load with old nftables versions Reported-by: Michal Kubecek Link: https://lore.kernel.org/netfilter-devel/20240206104336.ctigqpkunom2ufmn@lion.mk-sys.cz/ Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nft_byteorder.c | 51 ++++++++++++++--------------------- 1 file changed, 20 insertions(+), 31 deletions(-) diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c index 74548b4c114b9..391aade36ef3c 100644 --- a/net/netfilter/nft_byteorder.c +++ b/net/netfilter/nft_byteorder.c @@ -19,7 +19,6 @@ struct nft_byteorder { u8 sreg; u8 dreg; enum nft_byteorder_ops op:8; - u8 len; u8 size; }; @@ -28,13 +27,8 @@ void nft_byteorder_eval(const struct nft_expr *expr, const struct nft_pktinfo *pkt) { const struct nft_byteorder *priv = nft_expr_priv(expr); - u32 *src = ®s->data[priv->sreg]; + const u32 *src = ®s->data[priv->sreg]; u32 *dst = ®s->data[priv->dreg]; - u16 *s16, *d16; - unsigned int i; - - s16 = (void *)src; - d16 = (void *)dst; switch (priv->size) { case 8: { @@ -43,18 +37,14 @@ void nft_byteorder_eval(const struct nft_expr *expr, switch (priv->op) { case NFT_BYTEORDER_NTOH: - for (i = 0; i < priv->len / 8; i++) { - src64 = nft_reg_load64(&src[i]); - nft_reg_store64(&dst64[i], - be64_to_cpu((__force __be64)src64)); - } + src64 = nft_reg_load64(src); + + nft_reg_store64(dst64, be64_to_cpu((__force __be64)src64)); break; case NFT_BYTEORDER_HTON: - for (i = 0; i < priv->len / 8; i++) { - src64 = (__force __u64) - cpu_to_be64(nft_reg_load64(&src[i])); - nft_reg_store64(&dst64[i], src64); - } + src64 = (__force __u64)cpu_to_be64(nft_reg_load64(src)); + + nft_reg_store64(dst64, src64); break; } break; @@ -62,24 +52,20 @@ void nft_byteorder_eval(const struct nft_expr *expr, case 4: switch (priv->op) { case NFT_BYTEORDER_NTOH: - for (i = 0; i < priv->len / 4; i++) - dst[i] = ntohl((__force __be32)src[i]); + *dst = ntohl((__force __be32)*src); break; case NFT_BYTEORDER_HTON: - for (i = 0; i < priv->len / 4; i++) - dst[i] = (__force __u32)htonl(src[i]); + *dst = (__force __u32)htonl(*src); break; } break; case 2: switch (priv->op) { case NFT_BYTEORDER_NTOH: - for (i = 0; i < priv->len / 2; i++) - d16[i] = ntohs((__force __be16)s16[i]); + nft_reg_store16(dst, ntohs(nft_reg_load_be16(src))); break; case NFT_BYTEORDER_HTON: - for (i = 0; i < priv->len / 2; i++) - d16[i] = (__force __u16)htons(s16[i]); + nft_reg_store_be16(dst, htons(nft_reg_load16(src))); break; } break; @@ -137,20 +123,22 @@ static int nft_byteorder_init(const struct nft_ctx *ctx, if (err < 0) return err; - priv->len = len; + /* no longer support multi-reg conversions */ + if (len != size) + return -EOPNOTSUPP; err = nft_parse_register_load(ctx, tb[NFTA_BYTEORDER_SREG], &priv->sreg, - priv->len); + len); if (err < 0) return err; err = nft_parse_register_store(ctx, tb[NFTA_BYTEORDER_DREG], &priv->dreg, NULL, NFT_DATA_VALUE, - priv->len); + len); if (err < 0) return err; - if (nft_reg_overlap(priv->sreg, priv->dreg, priv->len)) + if (nft_reg_overlap(priv->sreg, priv->dreg, len)) return -EINVAL; return 0; @@ -167,10 +155,11 @@ static int nft_byteorder_dump(struct sk_buff *skb, goto nla_put_failure; if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op))) goto nla_put_failure; - if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len))) - goto nla_put_failure; if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size))) goto nla_put_failure; + /* compatibility for old userspace which permitted size != len */ + if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->size))) + goto nla_put_failure; return 0; nla_put_failure: -- 2.53.0