Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FDD8C433EF for ; Sat, 8 Jan 2022 22:26:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233500AbiAHW0w (ORCPT ); Sat, 8 Jan 2022 17:26:52 -0500 Received: from mail.netfilter.org ([217.70.188.207]:40126 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229943AbiAHW0u (ORCPT ); Sat, 8 Jan 2022 17:26:50 -0500 Received: from localhost.localdomain (unknown [78.30.32.163]) by mail.netfilter.org (Postfix) with ESMTPSA id 908606428F for ; Sat, 8 Jan 2022 23:24:00 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf-next,v2 13/14] netfilter: nft_payload: cancel register tracking after payload update Date: Sat, 8 Jan 2022 23:26:37 +0100 Message-Id: <20220108222638.36037-14-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220108222638.36037-1-pablo@netfilter.org> References: <20220108222638.36037-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org The payload expression might mangle the packet, cancel register tracking since any payload data in the registers is stale. Finer grain register tracking cancellation by inspecting the payload base, offset and length on the register is also possible. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index b5a3c45727b3..940fed9a760b 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -801,12 +801,33 @@ static int nft_payload_set_dump(struct sk_buff *skb, const struct nft_expr *expr return -1; } +static bool nft_payload_set_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + int i; + + for (i = 0; i < NFT_REG32_NUM; i++) { + if (!track->regs[i].selector) + continue; + + if (track->regs[i].selector->ops != &nft_payload_ops && + track->regs[i].selector->ops != &nft_payload_fast_ops) + continue; + + track->regs[i].selector = NULL; + track->regs[i].bitwise = NULL; + } + + return false; +} + static const struct nft_expr_ops nft_payload_set_ops = { .type = &nft_payload_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)), .eval = nft_payload_set_eval, .init = nft_payload_set_init, .dump = nft_payload_set_dump, + .reduce = nft_payload_set_reduce, }; static const struct nft_expr_ops * -- 2.30.2