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 36AB3C04FDF for ; Tue, 25 Jul 2023 11:44:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235055AbjGYLoZ (ORCPT ); Tue, 25 Jul 2023 07:44:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235099AbjGYLnw (ORCPT ); Tue, 25 Jul 2023 07:43:52 -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 0B2A11BD8 for ; Tue, 25 Jul 2023 04:43:50 -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 DF47F615BA for ; Tue, 25 Jul 2023 11:43:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0483C433C8; Tue, 25 Jul 2023 11:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690285429; bh=8GAmZO/WqNL3QSuzG71YUw7pfjZGk59m96FiseWY6EY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yp4XYsADTFXaF2nvpo46FgOHdzPiPNUgVWW04Ny5mjAftyMdfDwLiqjnfIi7PPgQP MUU1w3ejGzCjYzztUjVCuBKcrYTVJVLaLYMvH2w2hM2QY74VBXhdaGdR34lpNUnIYM siOqn3hvvq4J217MHNMxzaSZi27ijXLOHvcNoazM= 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 , Sasha Levin Subject: [PATCH 5.4 202/313] net/sched: cls_fw: Fix improper refcount update leads to use-after-free Date: Tue, 25 Jul 2023 12:45:55 +0200 Message-ID: <20230725104529.748573505@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104521.167250627@linuxfoundation.org> References: <20230725104521.167250627@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 [ Upstream commit 0323bce598eea038714f941ce2b22541c46d488f ] 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: Sasha Levin --- net/sched/cls_fw.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c index ec945294626a8..41f0898a5a565 100644 --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -210,11 +210,6 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp, 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); - } - if (tb[TCA_FW_INDEV]) { int ret; ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack); @@ -231,6 +226,11 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp, } 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; } -- 2.39.2