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 95765C433EF for ; Thu, 30 Sep 2021 06:20:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D565613A5 for ; Thu, 30 Sep 2021 06:20:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348275AbhI3GVm (ORCPT ); Thu, 30 Sep 2021 02:21:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348267AbhI3GVl (ORCPT ); Thu, 30 Sep 2021 02:21:41 -0400 Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9F88C06161C; Wed, 29 Sep 2021 23:19:58 -0700 (PDT) Received: by mail-lf1-x130.google.com with SMTP id i4so20885908lfv.4; Wed, 29 Sep 2021 23:19:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UYSzK2oRpRLs39P58LffOhEpmAopES8bceIpkauH90g=; b=K2KrpjzzON5G5Y57FE5DJZCvGli5VwvTTuC2WmoW/FukQj1QvK/mE+yLWqjQ++I0Z4 Ez4+hh6LJ8ple6Tv1ALAt5BZeVI6Shf6hdK4oo21E66EyCtj8hh9vieohy6gVUi3uVwh 431mUrsn2Xo0zxRBI6YCWLZZS01jHffvPsLI3AI/rssi/sbDDZPyUBGMyJ2q1m+pYOsn aWRJrEQSNCmmWg4k3gxa7BafV5qJSDD7ePmqYv6ePBTgV7gKJ75lipkZI6nN813dt1eb 3oqZTbzDxrNFn8Nf1q4G3j6ZqVxCxfebMCb6ZZuNX4tDYwzCWx6fcve82q2/VDjTDK18 aPzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UYSzK2oRpRLs39P58LffOhEpmAopES8bceIpkauH90g=; b=m/tsW+wKmTR0GDcvSaO2S+C+K+/MF630TIxlDyzr8eawadUbFTLYnLo39iOQj0uP5x uBBmt5+q1CQhi/mNfhVBQcFiHJhej4bqmuCfK5tWLKqpUC3NIw4ixPK+9iC3TcqrXeR5 +WazD0SSvm+7DGnjkTX8YVDTVHNsBpHG16+KDNzjOmS7na80+Re49TbpO99ZoG5aYQ1k j7wFuxaYCCcDHJuW/B1AUKq0njxodGl3lerEeSJKr/cJCy2gEHf5ZBFBnFjGis/06dLP b8NW5r9oaA26RkqCwZDRLoiUTLqaM2oU6kS9CyrqGCbJ3eUwe+XDu4YeYFS98Mh9dgRB xQ0A== X-Gm-Message-State: AOAM532Afoif4wTBCW1zBI0FcgYxHIk+3XLM4KVqsy//W0vllWRSV3Cb V81NxmFiLKsg87zveqleejQ= X-Google-Smtp-Source: ABdhPJwSAYLVz7LCHeX3el9rkXaztxr+oOA5U4cvjevnJDg42e6Zc2hPXLJuBdgjxSHSNNDxZirAtw== X-Received: by 2002:a2e:998a:: with SMTP id w10mr4120546lji.322.1632982797221; Wed, 29 Sep 2021 23:19:57 -0700 (PDT) Received: from localhost.localdomain ([217.117.245.149]) by smtp.gmail.com with ESMTPSA id a16sm252597lfr.186.2021.09.29.23.19.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Sep 2021 23:19:56 -0700 (PDT) From: Pavel Skripkin To: andrew@lunn.ch, hkallweit1@gmail.com, linux@armlinux.org.uk, davem@davemloft.net, kuba@kernel.org, buytenh@marvell.com, afleming@freescale.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Skripkin , syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com, Dan Carpenter Subject: [PATCH v3 2/2] phy: mdio: fix memory leak Date: Thu, 30 Sep 2021 09:19:54 +0300 Message-Id: <5745dea4e12268a3f6b0772317f1cf0f49dab958.1632982651.git.paskripkin@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- Changes in v3: s/==/=/ Added Dan's Reviewed-by tag Changes in v2: Removed new state, since MDIOBUS_UNREGISTERED can be used. Also, moved bus->state initialization _before_ device_register() call, because Yanfei's patch is reverted in [v2 1/2] --- 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 53f034fc2ef7..a5f910d4a7be 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -534,6 +534,13 @@ 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 realese + * 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