From patchwork Mon Jun 5 03:47:53 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: 9765421 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 B5ACB60353 for ; Mon, 5 Jun 2017 03:50:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A5BF026E69 for ; Mon, 5 Jun 2017 03:50:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A82B27FA3; Mon, 5 Jun 2017 03:50:10 +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 4BD8D26E69 for ; Mon, 5 Jun 2017 03:50:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751314AbdFEDsm (ORCPT ); Sun, 4 Jun 2017 23:48:42 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:36893 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751309AbdFEDsi (ORCPT ); Sun, 4 Jun 2017 23:48:38 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id f98072ff; Mon, 5 Jun 2017 03:48:28 +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=+iG8 fh1akOdU0hy7JPc3a3o9Lqs=; b=odS6MXAFp9Bs9BpPJ9Pb139ZBZjZpF18pils WnOZ+2tIp67SEk0iXViJCLH3YMmsz1DHTGa36bcb0+q1q8epLzArZV1aACmbvhWV 31tCCwRFfmHujBgSJCQnTDnGGK8s21G/tScaqeZar+PAQ5BJ6r3AlUrGQofTigH9 G4bopBrMNsPqef42GFgMZBlnZkrH6sq6POgnxPx18c6CN620zKf59/YhYTN7ZGwl xciiQJTs+EBhoRW6aUD97DYba9VT6mMuL0FVb8eKDrQV1QW1xraci3cYX+Lm0Krf AQRY8Qq8PKgCO5cRj5PK9L6u626n815+l2dkGbeuIDcrujQzxA== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 7b1f5ecf (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Mon, 5 Jun 2017 03:48:28 +0000 (UTC) From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman Cc: "Jason A. Donenfeld" , Herbert Xu Subject: [PATCH RFC v2 4/8] crypto/rng: ensure that the RNG is ready before using Date: Mon, 5 Jun 2017 05:47:53 +0200 Message-Id: <20170605034757.4803-5-Jason@zx2c4.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170605034757.4803-1-Jason@zx2c4.com> References: <20170605034757.4803-1-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. 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; }