From nobody Mon Sep 29 21:08:02 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 842F9C00140 for ; Tue, 16 Aug 2022 01:08:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346992AbiHPBIi (ORCPT ); Mon, 15 Aug 2022 21:08:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344075AbiHPBEC (ORCPT ); Mon, 15 Aug 2022 21:04:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77726B9594; Mon, 15 Aug 2022 13:50:51 -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 A4CB761291; Mon, 15 Aug 2022 20:50:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 961D7C433D6; Mon, 15 Aug 2022 20:50:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660596623; bh=ScgBIY3HQMCcOzB+zPgCsLe9LaGbzeQNrwHYt+biqjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZL2cjTB/4Kel1pII9n3yPetvyLQ5UpyYZjxMgbhEm0kbOmcalyXLHoZbknUIrURSH uJeeLgmHuYiPz4J184621CAAnE8DC8ZrddyCILlDKAr/m7Z7IksslqNDDv5Br0amkS 3CulBEehXgsFlg7Pj1brHDyvJIL7OBl/KP2zPWgI= 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 5.19 1138/1157] net_sched: cls_route: remove from list when handle is 0 Date: Mon, 15 Aug 2022 20:08:14 +0200 Message-Id: <20220815180525.971372875@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@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]);