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 4CF6AC00140 for ; Mon, 15 Aug 2022 20:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239805AbiHOUEc (ORCPT ); Mon, 15 Aug 2022 16:04:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230438AbiHOUDn (ORCPT ); Mon, 15 Aug 2022 16:03:43 -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 614027E310; Mon, 15 Aug 2022 11:54:21 -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 7BD23B8105D; Mon, 15 Aug 2022 18:54:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C189CC433D6; Mon, 15 Aug 2022 18:54:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589658; bh=ScgBIY3HQMCcOzB+zPgCsLe9LaGbzeQNrwHYt+biqjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lMo7c5wPmVajByEIjqnR1dSWAhL4IK9516rtYaSjZgtcOZFzZS5biOBqkcMMYpSG7 SHhnTxdRWnAL7O/AK+Hdj7duj4NZlrM+kpmVAAi826HGVblHxyqlxhniHv6+DB9CBR kFqAhJTLZm9MVjm1YwL8Nq14oBdaYWWdToE18QuE= 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 5.15 761/779] net_sched: cls_route: remove from list when handle is 0 Date: Mon, 15 Aug 2022 20:06:45 +0200 Message-Id: <20220815180409.960854834@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@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: linux-kernel@vger.kernel.org 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); - if (fold && fold->handle && f->handle != fold->handle) { + if (fold) { th = to_hash(fold->handle); h = from_hash(fold->handle >> 16); b = rtnl_dereference(head->table[th]);