From nobody Fri Oct 24 20:23:13 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 3F381C25B08 for ; Mon, 15 Aug 2022 23:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354144AbiHOXni (ORCPT ); Mon, 15 Aug 2022 19:43:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354103AbiHOXlO (ORCPT ); Mon, 15 Aug 2022 19:41:14 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6240D4B0D4; Mon, 15 Aug 2022 13:10:37 -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 ams.source.kernel.org (Postfix) with ESMTPS id 1D77BB80EA8; Mon, 15 Aug 2022 20:10:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70987C433C1; Mon, 15 Aug 2022 20:10:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660594234; bh=ScgBIY3HQMCcOzB+zPgCsLe9LaGbzeQNrwHYt+biqjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tw2FWiykrK1bkhIv8qkcZitUaQUIHdNeTchXoUhE2C6TauVC28CVTbuxS03LzI6GN ErWqSjA+uEor2/GncMkfG/B4DQyeBfv+PHY2ZMoMfu66IYlKYo1SRFGYVBOY8b4Jqp 5aNQ6X7kpSglz+pcvbVYCkLNJ2tt5RnaE/Av7+1o= 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 5.18 1076/1095] net_sched: cls_route: remove from list when handle is 0 Date: Mon, 15 Aug 2022 20:07:55 +0200 Message-Id: <20220815180513.560350758@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180429.240518113@linuxfoundation.org> References: <20220815180429.240518113@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]);