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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 37B26C2BA1A for ; Wed, 8 Apr 2020 13:38:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 04D5C20747 for ; Wed, 8 Apr 2020 13:38:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04D5C20747 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 72B848E0011; Wed, 8 Apr 2020 09:38:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6DBA38E000D; Wed, 8 Apr 2020 09:38:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C9B58E0011; Wed, 8 Apr 2020 09:38:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0023.hostedemail.com [216.40.44.23]) by kanga.kvack.org (Postfix) with ESMTP id 427168E000D for ; Wed, 8 Apr 2020 09:38:46 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id EB881801BEF0 for ; Wed, 8 Apr 2020 13:38:45 +0000 (UTC) X-FDA: 76684793010.20.alley87_123b5958fa432 X-HE-Tag: alley87_123b5958fa432 X-Filterd-Recvd-Size: 2756 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Wed, 8 Apr 2020 13:38:45 +0000 (UTC) IronPort-SDR: wBbfhFOLDb6PZeHU2VaE17gAxUyGWrl1N1nGe8Dxm0GotP1aJR1AxCn/9LhurZEE5WjsAEP6qv cbZ3l/NfA/sw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Apr 2020 06:38:42 -0700 IronPort-SDR: R22WpOEU8IKS8IgdXmswW399/H6U6WiPxgDyUhHCrxA3Ql3xyGoS+vJXGd7pEeMNTNLLln4tnj 6JsvN7gJlfHg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,358,1580803200"; d="scan'208";a="425136945" Received: from eefimov-mobl2.ger.corp.intel.com (HELO localhost) ([10.249.41.73]) by orsmga005.jf.intel.com with ESMTP; 08 Apr 2020 06:38:36 -0700 Date: Wed, 8 Apr 2020 16:38:35 +0300 From: Jarkko Sakkinen To: Waiman Long Cc: Andrew Morton , David Howells , James Morris , "Serge E. Hallyn" , linux-mm@kvack.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Joe Perches , Matthew Wilcox , David Rientjes Subject: Re: [PATCH v3] mm: Add kvfree_sensitive() for freeing sensitive data objects Message-ID: <20200408133835.GA4097@linux.intel.com> References: <20200407200318.11711-1-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200407200318.11711-1-longman@redhat.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Apr 07, 2020 at 04:03:18PM -0400, Waiman Long wrote: > For kvmalloc'ed data object that contains sensitive information like > cryptographic key, we need to make sure that the buffer is always > cleared before freeing it. Using memset() alone for buffer clearing may > not provide certainty as the compiler may compile it away. To be sure, > the special memzero_explicit() has to be used. > > This patch introduces a new kvfree_sensitive() for freeing those > sensitive data objects allocated by kvmalloc(). The relevnat places > where kvfree_sensitive() can be used are modified to use it. > > Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read") > Suggested-by: Linus Torvalds > Signed-off-by: Waiman Long Acked-by: Jarkko Sakkinen David, you want to pick this one? /Jarkko