From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753821AbaHAGqc (ORCPT ); Fri, 1 Aug 2014 02:46:32 -0400 Received: from mail.eperm.de ([89.247.134.16]:35199 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752542AbaHAGqb (ORCPT ); Fri, 1 Aug 2014 02:46:31 -0400 X-AuthUser: sm@eperm.de From: Stephan Mueller To: herbert@gondor.apana.org.au Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org Subject: [PATCH] DRBG: fix failure of generating multiple of 2**16 bytes Date: Thu, 31 Jul 2014 21:47:33 +0200 Message-ID: <7159935.MYAcUzQ1Ny@myon.chronox.de> User-Agent: KMail/4.12.5 (Linux/3.15.4-200.fc20.x86_64; KDE/4.12.5; x86_64; ; ) 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 The function drbg_generate_long slices the request into 2**16 byte or smaller chunks. However, the loop, however invokes the random number generation function with zero bytes when the request size is a multiple of 2**16 bytes. The fix prevents zero bytes requests. Signed-off-by: Stephan Mueller --- crypto/drbg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index ff975d9..7894db9 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1500,7 +1500,7 @@ static int drbg_generate_long(struct drbg_state *drbg, if (0 >= tmplen) return tmplen; len += tmplen; - } while (slice > 0); + } while (slice > 0 && (len < buflen)); return len; } -- 1.9.3