Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752496AbdFOL7r (ORCPT ); Thu, 15 Jun 2017 07:59:47 -0400 Received: from mail.eperm.de ([89.247.134.16]:60254 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752323AbdFOL7q (ORCPT ); Thu, 15 Jun 2017 07:59:46 -0400 From: Stephan =?ISO-8859-1?Q?M=FCller?= To: kernel-hardening@lists.openwall.com Cc: Michael Ellerman , "Theodore Ts'o" , "Jason A. Donenfeld" , Linux Crypto Mailing List , LKML , Greg Kroah-Hartman , David Miller , Eric Biggers Subject: Re: [kernel-hardening] Re: [PATCH v4 13/13] random: warn when kernel uses unseeded randomness Date: Thu, 15 Jun 2017 13:59:43 +0200 Message-ID: <1606799.lNpamfCTbW@tauon.chronox.de> In-Reply-To: <871sqlpl63.fsf@concordia.ellerman.id.au> References: <20170606174804.31124-1-Jason@zx2c4.com> <20170608081919.zbtwdjl32vbvd7jt@thunk.org> <871sqlpl63.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1042 Lines: 28 Am Donnerstag, 15. Juni 2017, 13:03:48 CEST schrieb Michael Ellerman: Hi Michael, > > Even with this patch, it's still pretty spammy (today's linux-next): > I would think that the issue regarding the logging is relevant for cryptographic use cases or use cases requiring strong random numbers only. Only those use cases should be fixed eventually to wait for a fully seeded DRNG. The logged messages you present here indicate use cases where no strong security is required. It looks like that the logs show ASLR related use of random numbers. Those do not require a fully seeded ChaCha20 DRNG. IMHO, users using the get_random_u64 or get_random_u32 are use cases that do not require a fully seeded DRNG thus do not need a cryptographically strong random number. Hence, I would think that the logging should be removed from get_random_u32/u64. Yet, logging should remain for get_random_bytes which should be denominated as the interface for use cases where cryptographically strong random numbers are required. Ciao Stephan