From nobody Fri Sep 5 20:15:07 2025 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 EC3F5C32772 for ; Tue, 23 Aug 2022 11:47:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358195AbiHWLrR (ORCPT ); Tue, 23 Aug 2022 07:47:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358467AbiHWLly (ORCPT ); Tue, 23 Aug 2022 07:41:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8305FCD538; Tue, 23 Aug 2022 02:29:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3474561388; Tue, 23 Aug 2022 09:29:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C91DC433D6; Tue, 23 Aug 2022 09:29:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246963; bh=ScgBIY3HQMCcOzB+zPgCsLe9LaGbzeQNrwHYt+biqjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cicRRGvk4mK2syW+JaD3JPQnwGfIPmKEYfj71SbBgOi+x4Jh4kNK6dIk5Gf5S5eZ6 IZ8zYUb/cuie/kQohSfz+aZV5OMnzK4qg6oHEX76a8+rvaaiK8Stv3MyzHXqWI4N8G nK8mN1HcokqPbUJb1X7+vEJpKqBL1g4SrDuMy1A8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhenpeng Lin , Thadeu Lima de Souza Cascardo , Kamal Mostafa , Jamal Hadi Salim , Jakub Kicinski Subject: [PATCH 5.4 275/389] net_sched: cls_route: remove from list when handle is 0 Date: Tue, 23 Aug 2022 10:25:53 +0200 Message-Id: <20220823080127.033009643@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080115.331990024@linuxfoundation.org> References: <20220823080115.331990024@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Thadeu Lima de Souza Cascardo commit 9ad36309e2719a884f946678e0296be10f0bb4c1 upstream. When a route filter is replaced and the old filter has a 0 handle, the old one won't be removed from the hashtable, while it will still be freed. The test was there since before commit 1109c00547fc ("net: sched: RCU cls_route"), when a new filter was not allocated when there was an old one. The old filter was reused and the reinserting would only be necessary if an old filter was replaced. That was still wrong for the same case where the old handle was 0. Remove the old filter from the list independently from its handle value. This fixes CVE-2022-2588, also reported as ZDI-CAN-17440. Reported-by: Zhenpeng Lin Signed-off-by: Thadeu Lima de Souza Cascardo Reviewed-by: Kamal Mostafa Cc: Acked-by: Jamal Hadi Salim Link: https://lore.kernel.org/r/20220809170518.164662-1-cascardo@canonical.= com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sched/cls_route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sched/cls_route.c +++ b/net/sched/cls_route.c @@ -526,7 +526,7 @@ static int route4_change(struct net *net rcu_assign_pointer(f->next, f1); rcu_assign_pointer(*fp, f); =20 - if (fold && fold->handle && f->handle !=3D fold->handle) { + if (fold) { th =3D to_hash(fold->handle); h =3D from_hash(fold->handle >> 16); b =3D rtnl_dereference(head->table[th]);