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 8558CC54796 for ; Tue, 23 Aug 2022 10:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356840AbiHWKwW (ORCPT ); Tue, 23 Aug 2022 06:52:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355775AbiHWKoS (ORCPT ); Tue, 23 Aug 2022 06:44:18 -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 A49B7AB044; Tue, 23 Aug 2022 02:10:29 -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 81870608D5; Tue, 23 Aug 2022 09:10:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88C53C433C1; Tue, 23 Aug 2022 09:10:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661245827; bh=PQwFh3y1zqnoCjaqteSP56ZnA2D0ZUNmXY2D9oi4lEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H/Tk5gZMTqvEqXGPHIc0S44svBVwcf52ATTIM3a8Vx0co5bCYkA2ScXTI2Zxwfq1g ME1Ybx7VsSRPwd8sjNDxOTSNMcjeQ6sdhKHnp/IErsri9nw2c/9F9INmFTc7J7n+uq qkJQZmiT8EwwNweOcR+kHAMY7YDcFKVbEVhFf1M0= 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 4.19 201/287] net_sched: cls_route: remove from list when handle is 0 Date: Tue, 23 Aug 2022 10:26:10 +0200 Message-Id: <20220823080107.633720163@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080100.268827165@linuxfoundation.org> References: <20220823080100.268827165@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 @@ -528,7 +528,7 @@ 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]);