From patchwork Tue Jun 6 17:47:56 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: 9769391 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 F2D4A6035D for ; Tue, 6 Jun 2017 17:49:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EDB3C2849E for ; Tue, 6 Jun 2017 17:49:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E0C9B284E3; Tue, 6 Jun 2017 17:49:23 +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 C7F012849E for ; Tue, 6 Jun 2017 17:49:22 +0000 (UTC) Received: (qmail 1686 invoked by uid 550); 6 Jun 2017 17:48:31 -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 1468 invoked from network); 6 Jun 2017 17:48:26 -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=F4DFtBN0TS1nAq7T2G9dgBtnKqJN1jb9eOjo 7pxN1/ZzsgkJ/yqsbYcZBwww33oPUr6a35qwkEuDNcj4ODVBoaG8g35Pgi1vQHZb 3xUp2Vmp4UkYuwTP2KBAENXZuPGiv4pJSRrSKHY2BYi26/bYprRZY3+uu8vickpt kV1jkJU5L1RE3L59+YcglYlgwZRgPLvcODF8oDub+pc/vrLyJd/SQVJRWx4ddLJz JyJMijrQT5I0nIbyJ+UO8UqUaiqkn7QOsZaDhdNiSNBeJEBapbdWGAVxxvZ2MP2O Wf3Qle8C09n/WRCjs0Z0PBrk7ASt/Xn1tIt9Kag34gq+JtO+Qg== From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , David Miller , Eric Biggers Cc: "Jason A. Donenfeld" , Herbert Xu Date: Tue, 6 Jun 2017 19:47:56 +0200 Message-Id: <20170606174804.31124-6-Jason@zx2c4.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170606174804.31124-1-Jason@zx2c4.com> References: <20170606174804.31124-1-Jason@zx2c4.com> Subject: [kernel-hardening] [PATCH v4 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; }