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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11E52C433F5 for ; Mon, 11 Oct 2021 14:17:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F00B760238 for ; Mon, 11 Oct 2021 14:17:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238000AbhJKOTL (ORCPT ); Mon, 11 Oct 2021 10:19:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:39266 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241233AbhJKOQF (ORCPT ); Mon, 11 Oct 2021 10:16:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C4B8761076; Mon, 11 Oct 2021 14:05:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633961152; bh=PgHwjF3wtrbnQbGkUF54xuFzIv4x4wSDnP6YuNA+2gU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eYYUNnwFBe1HHUlczi7W3Cf7dVnm9v3zrTMAoixFJCahYjSY2BpG495Jgh/QIZgRO 6bbcvCkcv5OQrpLFTyu2HZgU06ll708Zwo4Rnmi1t5bUOV8XvnHOvUvRKglcq20wJz 1YerMkYH/QIhfB+Mr5sRYIyFrGR76R+Gac2kXswI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Pavel Skripkin , Jakub Kicinski , Sasha Levin , syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com Subject: [PATCH 4.19 14/28] phy: mdio: fix memory leak Date: Mon, 11 Oct 2021 15:47:04 +0200 Message-Id: <20211011134641.172882204@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211011134640.711218469@linuxfoundation.org> References: <20211011134640.711218469@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: linux-kernel@vger.kernel.org From: Pavel Skripkin [ Upstream commit ca6e11c337daf7925ff8a2aac8e84490a8691905 ] Syzbot reported memory leak in MDIO bus interface, the problem was in wrong state logic. MDIOBUS_ALLOCATED indicates 2 states: 1. Bus is only allocated 2. Bus allocated and __mdiobus_register() fails, but device_register() was called In case of device_register() has been called we should call put_device() to correctly free the memory allocated for this device, but mdiobus_free() calls just kfree(dev) in case of MDIOBUS_ALLOCATED state To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED _before_ calling device_register(), because put_device() should be called even in case of device_register() failure. Link: https://lore.kernel.org/netdev/YVMRWNDZDUOvQjHL@shell.armlinux.org.uk/ Fixes: 46abc02175b3 ("phylib: give mdio buses a device tree presence") Reported-and-tested-by: syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com Reviewed-by: Dan Carpenter Signed-off-by: Pavel Skripkin Link: https://lore.kernel.org/r/eceae1429fbf8fa5c73dd2a0d39d525aa905074d.1633024062.git.paskripkin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/phy/mdio_bus.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 08c81d4cfca8..3207da2224f6 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -378,6 +378,13 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) bus->dev.groups = NULL; dev_set_name(&bus->dev, "%s", bus->id); + /* We need to set state to MDIOBUS_UNREGISTERED to correctly release + * the device in mdiobus_free() + * + * State will be updated later in this function in case of success + */ + bus->state = MDIOBUS_UNREGISTERED; + err = device_register(&bus->dev); if (err) { pr_err("mii_bus %s failed to register\n", bus->id); -- 2.33.0