From nobody Wed Sep 17 03:31:49 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D3A6C3DA7A for ; Thu, 22 Dec 2022 22:39:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235595AbiLVWjh (ORCPT ); Thu, 22 Dec 2022 17:39:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235442AbiLVWjd (ORCPT ); Thu, 22 Dec 2022 17:39:33 -0500 Received: from msg-4.mailo.com (msg-4.mailo.com [213.182.54.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCB9EA45A for ; Thu, 22 Dec 2022 14:39:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mailo.com; s=mailo; t=1671748768; bh=z8J0zWp2xScShPwwVbxBi7EfLHWTA83YkulZZUzCqCQ=; h=X-EA-Auth:Date:From:To:Cc:Subject:Message-ID:MIME-Version: Content-Type; b=aFgIbMQuvk47ps7/6m0SiLneAD6PXfeS8OXXpWTad9L2GZueB95X/dylAKf6RmlVd UchTzqfQ4ZhkRRZG2NUL1Llh1UBkXW41H2NSciMfBk16iA5uIxmUET1Sv19KC7T393 kFYlKe+CrwjdYeAR5WyXOrYC/d3w/Uhw3rWVrf8c= Received: by b-6.in.mailobj.net [192.168.90.16] with ESMTP via ip-206.mailobj.net [213.182.55.206] Thu, 22 Dec 2022 23:39:27 +0100 (CET) X-EA-Auth: +78mYshc1jvuTVNaSX5oSe5ppaMTDLnPHSBg/6O+0Uud39gcRigBQlR58ttQMV+b52Zi9yOXgzdg46jT2cnOtwo3GGkxzO5I Date: Fri, 23 Dec 2022 04:09:22 +0530 From: Deepak R Varma To: Evgeniy Polyakov , linux-kernel@vger.kernel.org Cc: Saurabh Singh Sengar , Praveen Kumar , drv@mailo.com Subject: [PATCH] w1: Use kfree_sensitive to clear sensitive information Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Replace combination of 'memset(0) + kfree()' by kfree_sensitive() as it prevents compiler from optimizing away from zeroing out memory at the end of a scope. kfree_sensitive() is also safe in case the memory pointer turns out to be null, which simply gets ignored. Issue identified using kfree_sensitive.cocci coccinelle semantic patch. Signed-off-by: Deepak R Varma --- Note: proposed change is compile tested only. drivers/w1/w1.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index f2ae2e563dc5..e08467e08b73 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -73,8 +73,7 @@ static void w1_master_release(struct device *dev) struct w1_master *md =3D dev_to_w1_master(dev); dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name); - memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); - kfree(md); + kfree_sensitive(md); } static void w1_slave_release(struct device *dev) @@ -805,9 +804,10 @@ int w1_unref_slave(struct w1_slave *sl) w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl); device_unregister(&sl->dev); #ifdef DEBUG - memset(sl, 0, sizeof(*sl)); - #endif + kfree_sensitive(sl); + #else kfree(sl); + #endif } atomic_dec(&dev->refcnt); mutex_unlock(&dev->list_mutex); -- 2.34.1