From patchwork Wed Jun 7 23:25:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 9773319 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6BB1F60234 for ; Wed, 7 Jun 2017 23:29:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5FF571FFF8 for ; Wed, 7 Jun 2017 23:29:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 52FAF28389; Wed, 7 Jun 2017 23:29:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E99931FFF8 for ; Wed, 7 Jun 2017 23:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751892AbdFGX3d (ORCPT ); Wed, 7 Jun 2017 19:29:33 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:55513 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753199AbdFGX01 (ORCPT ); Wed, 7 Jun 2017 19:26:27 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 35860cbe; Wed, 7 Jun 2017 23:25:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=from:to:cc :subject:date:message-id:in-reply-to:references; s=mail; bh=3zwV aD5VPcMrHsUWJ4U9cMhkG7M=; b=T7yuih/cEKCQKXLKYPvbOnG7bS6S6uSD7QtQ 12IGMom2jDAkpZBtCM0NaRX8xya1P64xHW1ccv48gBM/aPNL38NgBzckvz/naNqr eq+zjnnARohfoA1yWY8fnSFQ3PWE2d5D7+RT2xxCBe34ecZfXpHhAc7YVNjkicki 4nPcupoiPG/KU2Ot7psZ3uT/7tZMqwhXigZjpWcMDhEz2G8/tLS+SAjK/Fo2Njdk 8dRvZHEtkejwg1oDXDIoFu+9hP+DxZMHPn0Khf+mbV8F01UNvdxQzcm/ZhONJi8z mnesNrOseMpCCTfbQXAmjzLo2EeHRJIwZCQKnSOldbr45MphaA== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 0944202b (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Wed, 7 Jun 2017 23:25:52 +0000 (UTC) From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , Eric Biggers , Linus Torvalds , David Miller Cc: "Jason A. Donenfeld" , Herbert Xu Subject: [PATCH v5 05/13] crypto/rng: ensure that the RNG is ready before using Date: Thu, 8 Jun 2017 01:25:59 +0200 Message-Id: <20170607232607.26870-6-Jason@zx2c4.com> In-Reply-To: <20170607232607.26870-1-Jason@zx2c4.com> References: <20170607232607.26870-1-Jason@zx2c4.com> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Otherwise, we might be seeding the RNG using bad randomness, which is dangerous. The one use of this function from within the kernel -- not from userspace -- is being removed (keys/big_key), so that call site isn't relevant in assessing this. Cc: Herbert Xu Signed-off-by: Jason A. Donenfeld --- crypto/rng.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/crypto/rng.c b/crypto/rng.c index f46dac5288b9..e042437e64b4 100644 --- a/crypto/rng.c +++ b/crypto/rng.c @@ -48,12 +48,14 @@ int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) if (!buf) return -ENOMEM; - get_random_bytes(buf, slen); + err = get_random_bytes_wait(buf, slen); + if (err) + goto out; seed = buf; } err = crypto_rng_alg(tfm)->seed(tfm, seed, slen); - +out: kzfree(buf); return err; }