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: 9773275 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 12EAC60234 for ; Wed, 7 Jun 2017 23:27:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07849283AD for ; Wed, 7 Jun 2017 23:27:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F05612848D; Wed, 7 Jun 2017 23:27:21 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 0791A283AD for ; Wed, 7 Jun 2017 23:27:20 +0000 (UTC) Received: (qmail 26220 invoked by uid 550); 7 Jun 2017 23:26:30 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 26082 invoked from network); 7 Jun 2017 23:26:26 -0000 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== 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 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> Subject: [kernel-hardening] [PATCH v5 05/13] crypto/rng: ensure that the RNG is ready before using 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; }