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 X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E0E9C433B4 for ; Wed, 7 Apr 2021 23:01:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC4DE61242 for ; Wed, 7 Apr 2021 23:01:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229477AbhDGXB2 (ORCPT ); Wed, 7 Apr 2021 19:01:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:59978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbhDGXB2 (ORCPT ); Wed, 7 Apr 2021 19:01:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2D5C7611C9; Wed, 7 Apr 2021 23:01:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617836478; bh=Z7WqCUanSlNvnD9wexNvEc3dx0BZpbT+4uVfy5X9skQ=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=AD9RsG1MszT7GTAMUnWeZhwOTLC5s3l0DrH6BnTkqDkKT0q18MV8IYE6Zy0t7p5Ok m7vfcNJ+KrsG5vKPysOXjwIU8Ddzt5lPY/swg7C+T4xQKlOqtsugxVnOr08V01rqjm +b4gnM0uRwAQvV1c8+OLWg24WeT+BrQY55ACrC6DdrvdUNhgwcIVSwOh04wb4Tmyra CMfM1W90tDzF9smEKQ8sDIaRLgKXK4oa1KkHVRq2BUPrZVObCC3LbpyZUH8e5v3nyh 6Qq5uTvDfaffUx5Jis1ztg2qckI8AC2GPSNxRE+OlyvyQNb9fraw/7coh+lGkjbsAm SdcW9KKg06CAA== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20210406230606.3007138-1-dmitry.baryshkov@linaro.org> References: <20210406230606.3007138-1-dmitry.baryshkov@linaro.org> Subject: Re: [PATCH] clk: fixed: fix double free in resource managed fixed-factor clock From: Stephen Boyd Cc: linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, Rob Clark , Daniel Palmer To: Andy Gross , Bjorn Andersson , Dmitry Baryshkov , Michael Turquette Date: Wed, 07 Apr 2021 16:01:16 -0700 Message-ID: <161783647690.3790633.7004111396421583619@swboyd.mtv.corp.google.com> User-Agent: alot/0.9.1 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Quoting Dmitry Baryshkov (2021-04-06 16:06:06) > devm_clk_hw_register_fixed_factor_release(), the release function for > the devm_clk_hw_register_fixed_factor(), calls > clk_hw_unregister_fixed_factor(), which will kfree() the clock. However > after that the devres functions will also kfree the allocated data, > resulting in double free/memory corruption. Just call > clk_hw_unregister() instead, leaving kfree() to devres code. >=20 > Reported-by: Rob Clark > Cc: Daniel Palmer > Signed-off-by: Dmitry Baryshkov > --- Applied to clk-fixes. I also squashed this in to cleanup that ugly cast. ---8<---- diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c index 390c16f321a6..4e4b6d367612 100644 --- a/drivers/clk/clk-fixed-factor.c +++ b/drivers/clk/clk-fixed-factor.c @@ -66,12 +66,14 @@ EXPORT_SYMBOL_GPL(clk_fixed_factor_ops); =20 static void devm_clk_hw_register_fixed_factor_release(struct device *dev, = void *res) { + struct clk_fixed_factor *fix =3D res; + /* * We can not use clk_hw_unregister_fixed_factor, since it will kfree() * the hw, resulting in double free. Just unregister the hw and let * devres code kfree() it. */ - clk_hw_unregister(&((struct clk_fixed_factor *)res)->hw); + clk_hw_unregister(&fix->hw); } =20 static struct clk_hw *