From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757361Ab2HGDyk (ORCPT ); Mon, 6 Aug 2012 23:54:40 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:59631 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757284Ab2HGDiL (ORCPT ); Mon, 6 Aug 2012 23:38:11 -0400 Message-Id: <20120807032757.853527625@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Tue, 07 Aug 2012 04:28:07 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Theodore Tso , "H. Peter Anvin" Subject: [ 12/70] random: Use arch-specific RNG to initialize the entropy store In-Reply-To: <20120807032755.803571133@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o commit 3e88bdff1c65145f7ba297ccec69c774afe4c785 upstream. If there is an architecture-specific random number generator (such as RDRAND for Intel architectures), use it to initialize /dev/random's entropy stores. Even in the worst case, if RDRAND is something like AES(NSA_KEY, counter++), it won't hurt, and it will definitely help against any other adversaries. Signed-off-by: "Theodore Ts'o" Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@mit.edu Signed-off-by: H. Peter Anvin Signed-off-by: Ben Hutchings --- drivers/char/random.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/char/random.c b/drivers/char/random.c index 85da874..3079477 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -965,6 +965,7 @@ EXPORT_SYMBOL(get_random_bytes); */ static void init_std_data(struct entropy_store *r) { + int i; ktime_t now; unsigned long flags; @@ -974,6 +975,11 @@ static void init_std_data(struct entropy_store *r) now = ktime_get_real(); mix_pool_bytes(r, &now, sizeof(now)); + for (i = r->poolinfo->poolwords; i; i--) { + if (!arch_get_random_long(&flags)) + break; + mix_pool_bytes(r, &flags, sizeof(flags)); + } mix_pool_bytes(r, utsname(), sizeof(*(utsname()))); }