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 3A601C433FE for ; Wed, 24 Nov 2021 12:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243990AbhKXMZV (ORCPT ); Wed, 24 Nov 2021 07:25:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:42144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244749AbhKXMYK (ORCPT ); Wed, 24 Nov 2021 07:24:10 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A024861053; Wed, 24 Nov 2021 12:14:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637756070; bh=g5nifpUJN2RkH6er6+T6k4+356+3J7aV2BJUIElogRE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hb1kUqvoT8CHwbS8WorKIxaRxDZf3/rx6oVPLvSUsxkpW+owYv34p5rigUo4qPkuZ zbYi2n10Mo/LQ0tcepjdzOgvsnPg24ufhgZIeNSdpQrjYYRiMet5ZJX9CY/2eXe4DM hfH7lRYBHd6Usk+6uGkbIFK4aN7Paos1L8F9xjBg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Corentin Labbe , Andrew Lunn , "David S. Miller" , Florian Fainelli Subject: [PATCH 4.9 159/207] net: mdio-mux: fix unbalanced put_device Date: Wed, 24 Nov 2021 12:57:10 +0100 Message-Id: <20211124115709.158453042@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115703.941380739@linuxfoundation.org> References: <20211124115703.941380739@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Corentin Labbe commit 60f786525032432af1b7d9b8935cb12936244ccd upstream. mdio_mux_uninit() call put_device (unconditionally) because of of_mdio_find_bus() in mdio_mux_init. But of_mdio_find_bus is only called if mux_bus is empty. If mux_bus is set, mdio_mux_uninit will print a "refcount_t: underflow" trace. This patch add a get_device in the other branch of "if (mux_bus)". Signed-off-by: Corentin Labbe Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Florian Fainelli Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/mdio-mux.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/net/phy/mdio-mux.c +++ b/drivers/net/phy/mdio-mux.c @@ -117,6 +117,7 @@ int mdio_mux_init(struct device *dev, } else { parent_bus_node = NULL; parent_bus = mux_bus; + get_device(&parent_bus->dev); } pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL); @@ -182,9 +183,7 @@ int mdio_mux_init(struct device *dev, devm_kfree(dev, pb); err_pb_kz: - /* balance the reference of_mdio_find_bus() took */ - if (!mux_bus) - put_device(&parent_bus->dev); + put_device(&parent_bus->dev); err_parent_bus: of_node_put(parent_bus_node); return ret_val; @@ -202,7 +201,6 @@ void mdio_mux_uninit(void *mux_handle) cb = cb->next; } - /* balance the reference of_mdio_find_bus() in mdio_mux_init() took */ put_device(&pb->mii_bus->dev); } EXPORT_SYMBOL_GPL(mdio_mux_uninit);