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 C8453C433F5 for ; Thu, 14 Oct 2021 14:55:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1E5A611C2 for ; Thu, 14 Oct 2021 14:55:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232164AbhJNO5c (ORCPT ); Thu, 14 Oct 2021 10:57:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:42290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232123AbhJNO5W (ORCPT ); Thu, 14 Oct 2021 10:57:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6504360F4A; Thu, 14 Oct 2021 14:55:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1634223318; bh=cDrA1jZFkxemkgTkATXwogA2EjutUnYO21kUTWeFPFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dBgOEnkiXS8+Wtascy0W5Ty+3MKmb1ZRIUub+1CVXy3WRZebdDkzj+gLtf2Ivl7bB a/ukCaZ4VxKEVT9tC6rpZcGkJA/iqKAd8+Y8z6uBkwBpc3QC6TAYgtucxBli4QuBnW lyOIuUA1vzWz6sHIzTo01sz4eBNDxDUDC29qin9Y= 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 4.4 05/18] phy: mdio: fix memory leak Date: Thu, 14 Oct 2021 16:53:37 +0200 Message-Id: <20211014145206.495207097@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211014145206.330102860@linuxfoundation.org> References: <20211014145206.330102860@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 5ea86fd57ae6..4066fb5a935a 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -264,6 +264,13 @@ 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