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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B0E2C10F11 for ; Mon, 22 Apr 2019 20:01:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31981204EC for ; Mon, 22 Apr 2019 20:01:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555963275; bh=mcmamO7Oh+IA5VVXze+//Ym8Kz+7TgLgMJ+OLyC967U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0Eu0miLK3O7+P6fZQ0cgy8L63Bzw/oYNr66CgVLh8CbKG1e0bofzvtRTAvk6dtD8y PrbMhh7NAK2mbqGfarJoalz5iXDTRj2lQlqiZ4f+ZI2DqTyd/YuWV/ZtZ+L5VIudKN Ou0mevxEQIRNVCWvUUwN1wIFAz8up4ZDv99IV+kE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731959AbfDVUBO (ORCPT ); Mon, 22 Apr 2019 16:01:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:49600 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730145AbfDVTrB (ORCPT ); Mon, 22 Apr 2019 15:47:01 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3166C21906; Mon, 22 Apr 2019 19:47:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962420; bh=mcmamO7Oh+IA5VVXze+//Ym8Kz+7TgLgMJ+OLyC967U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aFrcl+VThllPklk4LLg9lWdl5L65Ugu5aBeXtZWAQvd53htJTEdx9yinoI6gpwULS s+72UL4cnreRyuf89VAZGjDW+pjZww6BvtIyqfrjOKV/2BMzAF4fj1O/JoTx+L1AKr D2N91lm6YnzhUCYtwC6gviS7hK5ZRI/wiWvJYx1I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Jacek Anaszewski , Sasha Levin , linux-leds@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 53/68] leds: trigger: netdev: fix refcnt leak on interface rename Date: Mon, 22 Apr 2019 15:45:01 -0400 Message-Id: <20190422194516.11634-53-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190422194516.11634-1-sashal@kernel.org> References: <20190422194516.11634-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafał Miłecki [ Upstream commit 4cb6560514fa19d556954b88128f3846fee66a03 ] Renaming a netdev-trigger-tracked interface was resulting in an unbalanced dev_hold(). Example: > iw phy phy0 interface add foo type __ap > echo netdev > trigger > echo foo > device_name > ip link set foo name bar > iw dev bar del [ 237.355366] unregister_netdevice: waiting for bar to become free. Usage count = 1 [ 247.435362] unregister_netdevice: waiting for bar to become free. Usage count = 1 [ 257.545366] unregister_netdevice: waiting for bar to become free. Usage count = 1 Above problem was caused by trigger checking a dev->name which obviously changes after renaming an interface. It meant missing all further events including the NETDEV_UNREGISTER which is required for calling dev_put(). This change fixes that by: 1) Comparing device struct *address* for notification-filtering purposes 2) Dropping unneeded NETDEV_CHANGENAME code (no behavior change) Fixes: 06f502f57d0d ("leds: trigger: Introduce a NETDEV trigger") Signed-off-by: Rafał Miłecki Acked-by: Pavel Machek Signed-off-by: Jacek Anaszewski Signed-off-by: Sasha Levin (Microsoft) --- drivers/leds/trigger/ledtrig-netdev.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c index 3dd3ed46d473..167a94c02d05 100644 --- a/drivers/leds/trigger/ledtrig-netdev.c +++ b/drivers/leds/trigger/ledtrig-netdev.c @@ -301,11 +301,11 @@ static int netdev_trig_notify(struct notifier_block *nb, container_of(nb, struct led_netdev_data, notifier); if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE - && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER - && evt != NETDEV_CHANGENAME) + && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER) return NOTIFY_DONE; - if (strcmp(dev->name, trigger_data->device_name)) + if (!(dev == trigger_data->net_dev || + (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name)))) return NOTIFY_DONE; cancel_delayed_work_sync(&trigger_data->work); @@ -320,12 +320,9 @@ static int netdev_trig_notify(struct notifier_block *nb, dev_hold(dev); trigger_data->net_dev = dev; break; - case NETDEV_CHANGENAME: case NETDEV_UNREGISTER: - if (trigger_data->net_dev) { - dev_put(trigger_data->net_dev); - trigger_data->net_dev = NULL; - } + dev_put(trigger_data->net_dev); + trigger_data->net_dev = NULL; break; case NETDEV_UP: case NETDEV_CHANGE: -- 2.19.1