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 A2F5CC433EF for ; Mon, 27 Sep 2021 11:20:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B76D60F4A for ; Mon, 27 Sep 2021 11:20:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234056AbhI0LWN (ORCPT ); Mon, 27 Sep 2021 07:22:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234049AbhI0LV7 (ORCPT ); Mon, 27 Sep 2021 07:21:59 -0400 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66AC3C061714; Mon, 27 Sep 2021 04:20:21 -0700 (PDT) Received: by mail-lf1-x12b.google.com with SMTP id b15so74881375lfe.7; Mon, 27 Sep 2021 04:20:21 -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:mime-version :content-transfer-encoding; bh=IM0udcg7Exs9Wnno0uDS6E62zPZhOJr/cycPpKfnVQk=; b=L/8MgV0oyeUPafvMVbtVmDu6G4fF5NWkGlFnkakoW6A0bmCaZYF6m8mJPsAnlfgUv6 bQwfyboY2aMAG+yBz7WnKoQeJDIMKxTVOAPa7i0GHwMl66BG7AfTdcbJ8qLKYbOHoJOG JGKcc591VuF3xRKTGo7wZZzjlImrv/NGMlYdsV++U6hGXd/WkWbO8M0EH/fTkFxoWIeG xwRPGBWRaKip8p0kelTi2jtXzGrWo4O4N9ptR+eQ9Nz2gBTaF3liuj+pb6ExopGrKBeu obY1Ref6pkgYjWXbQL1wPpA2kOhpOX3N+YD6wGpK+JrCpJziQoxAaPXw8C0rbXyiixhH 3NJw== 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:mime-version :content-transfer-encoding; bh=IM0udcg7Exs9Wnno0uDS6E62zPZhOJr/cycPpKfnVQk=; b=2nh/H/XX2gAaZ9ah9L8t+DCqdAIN+DWWFmsyCGKb7F6IVEBP9vFbeSeQMiDmGFTZRc 6R0R/I5q5jtJs4nIfuyVeRzB6HBSuaJe2u2M6thwsq7Bjn7sRY+uBs4nKXiqFgurbVNX LKyenTicTNsvm8ygG/JXT4fIQfz4RQAo4w6AP5gi/dBSIWqglkJVRh4+NswV9uW9BM02 qMhyAr5lV/RxLxLtTl10f8hJxiCHX7rS3+YqpBC7weq8l+wC6iNYhNy3UFlSihqJKu1s qnNGHY43yoSZMGWrsIS5iayfah84tw1TT5n90FmGquiVJ0tvcVxiSwul/A+2gwwKsPuo m4Ww== X-Gm-Message-State: AOAM53161W8e4MYfpdWZ4mZdeBBjth6iyRy8tMSnwhi0N//fsQrNlXg8 qEVAOBl6oWI1tLIL6C8JsgM= X-Google-Smtp-Source: ABdhPJxxCsdNzj//iPQCyzCjltNqYaesAyRbJIFqOu6djIN1chwsISnVFjpzf1PB0yJt89PxuZrJbg== X-Received: by 2002:a05:6512:3ba5:: with SMTP id g37mr23275112lfv.651.1632741619712; Mon, 27 Sep 2021 04:20:19 -0700 (PDT) Received: from localhost.localdomain ([217.117.245.149]) by smtp.gmail.com with ESMTPSA id p8sm1387002lft.242.2021.09.27.04.20.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Sep 2021 04:20:18 -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 Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Skripkin , syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com Subject: [PATCH] phy: mdio: fix memory leak Date: Mon, 27 Sep 2021 14:20:17 +0300 Message-Id: <20210927112017.19108-1-paskripkin@gmail.com> X-Mailer: git-send-email 2.33.0 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() was just calling kfree(dev) in case of MDIOBUS_ALLOCATED state To avoid this behaviour we can add new intermediate state, which means, that we have called device_regiter(), but failed on any of the next steps. Clean up process for this state is the same as for MDIOBUS_UNREGISTERED, but MDIOBUS_UNREGISTERED name does not fit to the logic described above. Fixes: 46abc02175b3 ("phylib: give mdio buses a device tree presence") Reported-and-tested-by: syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin --- drivers/net/phy/mdio_bus.c | 4 +++- include/linux/phy.h | 1 + 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 53f034fc2ef7..ed764638b449 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -540,6 +540,8 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) return -EINVAL; } + bus->state = MDIOBUS_DEV_REGISTERED; + mutex_init(&bus->mdio_lock); mutex_init(&bus->shared_lock); @@ -647,7 +649,7 @@ void mdiobus_free(struct mii_bus *bus) return; } - BUG_ON(bus->state != MDIOBUS_UNREGISTERED); + BUG_ON(bus->state != MDIOBUS_UNREGISTERED && bus->state != MDIOBUS_DEV_REGISTERED); bus->state = MDIOBUS_RELEASED; put_device(&bus->dev); diff --git a/include/linux/phy.h b/include/linux/phy.h index 736e1d1a47c4..41d2ccdacd5e 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -343,6 +343,7 @@ struct mii_bus { MDIOBUS_REGISTERED, MDIOBUS_UNREGISTERED, MDIOBUS_RELEASED, + MDIOBUS_DEV_REGISTERED, } state; /** @dev: Kernel device representation */ -- 2.33.0