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 4AF77CDB474 for ; Mon, 23 Oct 2023 11:22:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233839AbjJWLWc (ORCPT ); Mon, 23 Oct 2023 07:22:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233840AbjJWLWb (ORCPT ); Mon, 23 Oct 2023 07:22:31 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E11D4100 for ; Mon, 23 Oct 2023 04:22:28 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 254B8C433C8; Mon, 23 Oct 2023 11:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698060148; bh=PIAp5+viyOY56Bfh+rq+wGF4hzjCzjEe9SDhpABfQvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o2BDHb0rt76hdcHhGOYJhrCW5YBHiLsGAANjMmsJSNkZpZ8IXzO2JU0XRSx5B2VY/ /2EKrddMkOUFcgjMtNE6ElP7RisTYIODDN0v+qHDCq8XN5+zlKlvGuSDIYxD0fpipT JOg1l4rvy3Q/Sz6EuiPEVpS3sN/vD657GhEqwMGA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiri Pirko , Jakub Kicinski , Paolo Abeni Subject: [PATCH 6.1 074/196] net: avoid UAF on deleted altname Date: Mon, 23 Oct 2023 12:55:39 +0200 Message-ID: <20231023104830.643689815@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104828.488041585@linuxfoundation.org> References: <20231023104828.488041585@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jakub Kicinski commit 1a83f4a7c156fa6bbd6b530e89fa3270bf3d9d1b upstream. Altnames are accessed under RCU (dev_get_by_name_rcu()) but freed by kfree() with no synchronization point. Each node has one or two allocations (node and a variable-size name, sometimes the name is netdev->name). Adding rcu_heads here is a bit tedious. Besides most code which unlists the names already has rcu barriers - so take the simpler approach of adding synchronize_rcu(). Note that the one on the unregistration path (which matters more) is removed by the next fix. Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist") Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -345,7 +345,6 @@ int netdev_name_node_alt_create(struct n static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node) { list_del(&name_node->list); - netdev_name_node_del(name_node); kfree(name_node->name); netdev_name_node_free(name_node); } @@ -364,6 +363,8 @@ int netdev_name_node_alt_destroy(struct if (name_node == dev->name_node || name_node->dev != dev) return -EINVAL; + netdev_name_node_del(name_node); + synchronize_rcu(); __netdev_name_node_alt_destroy(name_node); return 0; @@ -10835,6 +10836,7 @@ void unregister_netdevice_many(struct li synchronize_net(); list_for_each_entry(dev, head, unreg_list) { + struct netdev_name_node *name_node; struct sk_buff *skb = NULL; /* Shutdown queueing discipline. */ @@ -10860,6 +10862,9 @@ void unregister_netdevice_many(struct li dev_uc_flush(dev); dev_mc_flush(dev); + netdev_for_each_altname(dev, name_node) + netdev_name_node_del(name_node); + synchronize_rcu(); netdev_name_node_alt_flush(dev); netdev_name_node_free(dev->name_node);