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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DBCF7C433EF for ; Sat, 12 Mar 2022 00:15:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229737AbiCLAQs (ORCPT ); Fri, 11 Mar 2022 19:16:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229709AbiCLAQr (ORCPT ); Fri, 11 Mar 2022 19:16:47 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A9EFFFF6 for ; Fri, 11 Mar 2022 16:15:42 -0800 (PST) Received: from localhost.localdomain (unknown [78.30.32.163]) by mail.netfilter.org (Postfix) with ESMTPSA id 60CBB60240 for ; Sat, 12 Mar 2022 01:13:36 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf-next] netfilter: nft_payload: only cancel tracking for clobbered dregs Date: Sat, 12 Mar 2022 01:15:38 +0100 Message-Id: <20220312001538.23128-1-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org payload expression might use more than one single register and clobber previous data, reset tracking for the remaining registers too. Fixes: a7c176bf9f0e ("netfilter: nft_payload: track register operations") Reported-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 5cc06aef4345..431f70c8bc15 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -210,6 +210,23 @@ static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr) return -1; } +static void nft_update_reg_track(struct nft_regs_track *track, + const struct nft_expr *expr, u8 dreg, u8 len) +{ + unsigned int regcount; + int i; + + track->regs[dreg].selector = expr; + track->regs[dreg].bitwise = NULL; + + dreg++; + regcount = DIV_ROUND_UP(len, NFT_REG32_SIZE); + for (i = 1; i < regcount; i++, dreg++) { + track->regs[dreg].selector = NULL; + track->regs[dreg].bitwise = NULL; + } +} + static bool nft_payload_reduce(struct nft_regs_track *track, const struct nft_expr *expr) { @@ -218,8 +235,7 @@ static bool nft_payload_reduce(struct nft_regs_track *track, if (!track->regs[priv->dreg].selector || track->regs[priv->dreg].selector->ops != expr->ops) { - track->regs[priv->dreg].selector = expr; - track->regs[priv->dreg].bitwise = NULL; + nft_update_reg_track(track, expr, priv->dreg, priv->len); return false; } @@ -227,8 +243,7 @@ static bool nft_payload_reduce(struct nft_regs_track *track, if (priv->base != payload->base || priv->offset != payload->offset || priv->len != payload->len) { - track->regs[priv->dreg].selector = expr; - track->regs[priv->dreg].bitwise = NULL; + nft_update_reg_track(track, expr, priv->dreg, priv->len); return false; } -- 2.30.2