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=-13.0 required=3.0 tests=BAYES_00, 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 B02C2C433E4 for ; Tue, 28 Jul 2020 18:15:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 94E742070B for ; Tue, 28 Jul 2020 18:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732263AbgG1SPz (ORCPT ); Tue, 28 Jul 2020 14:15:55 -0400 Received: from correo.us.es ([193.147.175.20]:41202 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732261AbgG1SPz (ORCPT ); Tue, 28 Jul 2020 14:15:55 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 585DC15AEB0 for ; Tue, 28 Jul 2020 20:15:53 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 46DDEDA722 for ; Tue, 28 Jul 2020 20:15:53 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 3C3CBDA78B; Tue, 28 Jul 2020 20:15:53 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 1C3C5DA78F for ; Tue, 28 Jul 2020 20:15:51 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Tue, 28 Jul 2020 20:15:51 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from localhost.localdomain (unknown [90.77.255.23]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id F32D34265A2F for ; Tue, 28 Jul 2020 20:15:50 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nft 3/3] evaluate: UAF in hook priority expression Date: Tue, 28 Jul 2020 20:15:46 +0200 Message-Id: <20200728181546.12663-3-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200728181546.12663-1-pablo@netfilter.org> References: <20200728181546.12663-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Release priority expression right before assigning the constant expression that results from the evaluation. Fixes: 627c451b2351 ("src: allow variables in the chain priority specification") Signed-off-by: Pablo Neira Ayuso --- src/evaluate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/evaluate.c b/src/evaluate.c index 536325e83537..7f93621827e6 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -3707,7 +3707,6 @@ static bool evaluate_priority(struct eval_ctx *ctx, struct prio_spec *prio, mpz_export_data(prio_str, prio->expr->value, BYTEORDER_HOST_ENDIAN, NFT_NAME_MAXLEN); loc = prio->expr->location; - expr_free(prio->expr); if (sscanf(prio_str, "%s %c %d", prio_fst, &op, &prio_snd) < 3) { priority = std_prio_lookup(prio_str, family, hook); @@ -3724,6 +3723,7 @@ static bool evaluate_priority(struct eval_ctx *ctx, struct prio_spec *prio, else return false; } + expr_free(prio->expr); prio->expr = constant_expr_alloc(&loc, &integer_type, BYTEORDER_HOST_ENDIAN, sizeof(int) * BITS_PER_BYTE, -- 2.20.1