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 CC913C001B0 for ; Wed, 9 Aug 2023 11:24:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233659AbjHILYQ (ORCPT ); Wed, 9 Aug 2023 07:24:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233653AbjHILYP (ORCPT ); Wed, 9 Aug 2023 07:24:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CAC2ED for ; Wed, 9 Aug 2023 04:24:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 963DF63244 for ; Wed, 9 Aug 2023 11:24:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0821C433C7; Wed, 9 Aug 2023 11:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580254; bh=uNcZl0PnwTKu+5JjANOE9jF+i4lzvHYeRu4CfuqlW5M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xSe5YbOmajy6oncQUP0SQbU0rglBRVr6dQUkAsnj8zuhOjrPeOZ2RBcjDTiL0o7tZ M9lZ15rrcYJRd0EJocr6us9G776PmQyzPFvjrS/TauJEmdqTkeWLLqyrcZC1stHHgc WmgTRCSxVKF5qx9t+y3jdsz0tmJuUbbQGw13vEhE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, M A Ramdhan , Jamal Hadi Salim , Pedro Tammela , Jakub Kicinski , SeongJae Park Subject: [PATCH 4.19 283/323] net/sched: cls_fw: Fix improper refcount update leads to use-after-free Date: Wed, 9 Aug 2023 12:42:01 +0200 Message-ID: <20230809103710.997747756@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103658.104386911@linuxfoundation.org> References: <20230809103658.104386911@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: M A Ramdhan commit 0323bce598eea038714f941ce2b22541c46d488f upstream. In the event of a failure in tcf_change_indev(), fw_set_parms() will immediately return an error after incrementing or decrementing reference counter in tcf_bind_filter(). If attacker can control reference counter to zero and make reference freed, leading to use after free. In order to prevent this, move the point of possible failure above the point where the TC_FW_CLASSID is handled. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: M A Ramdhan Signed-off-by: M A Ramdhan Acked-by: Jamal Hadi Salim Reviewed-by: Pedro Tammela Message-ID: <20230705161530.52003-1-ramdhan@starlabs.sg> Signed-off-by: Jakub Kicinski Signed-off-by: SeongJae Park Signed-off-by: Greg Kroah-Hartman --- net/sched/cls_fw.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -221,11 +221,6 @@ static int fw_set_parms(struct net *net, if (err < 0) return err; - if (tb[TCA_FW_CLASSID]) { - f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]); - tcf_bind_filter(tp, &f->res, base); - } - #ifdef CONFIG_NET_CLS_IND if (tb[TCA_FW_INDEV]) { int ret; @@ -244,6 +239,11 @@ static int fw_set_parms(struct net *net, } else if (head->mask != 0xFFFFFFFF) return err; + if (tb[TCA_FW_CLASSID]) { + f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]); + tcf_bind_filter(tp, &f->res, base); + } + return 0; }