From patchwork Wed Jun 7 23:26:04 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: 9773301 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 C712960393 for ; Wed, 7 Jun 2017 23:28:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BC233283AD for ; Wed, 7 Jun 2017 23:28:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B06882848D; Wed, 7 Jun 2017 23:28:29 +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 CEADE283AD for ; Wed, 7 Jun 2017 23:28:28 +0000 (UTC) Received: (qmail 31849 invoked by uid 550); 7 Jun 2017 23:27:02 -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 26376 invoked from network); 7 Jun 2017 23:26:35 -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=Wx3E csjwLHV0PI0DLBl591GMgPQ=; b=SFkXUI74my0uKPdaW2Jm9XNquGMA26j91Cs4 QZuPpAEQ7HrCOBr88zZaV/OO5MlkB2WgWt1a+N9neN3ZjPdgSebhpXiqoPIstlCC iWgVIwBrbG0LTRuC5NULKX1ZImcZX0HsqcFgi1mq94I4yChNftMYTCO5P98Cf+0U 6vNIHXPFdgQqUeek8kdOgPE0IY0BwhEjFEW3IdzcB6F2HZolUf/MSEzaobE6Nedt Y/rBsR2xdrxBNeeusZ0YoN8FzMkz/ilmmgEDkoksDrkSRMoatE8klPmvspiEi3KX jGho0CPDI6scKDjSpynLZZptfE08FNJirhz002qukN8IzDwI+w== 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" Date: Thu, 8 Jun 2017 01:26:04 +0200 Message-Id: <20170607232607.26870-11-Jason@zx2c4.com> In-Reply-To: <20170607232607.26870-1-Jason@zx2c4.com> References: <20170607232607.26870-1-Jason@zx2c4.com> Subject: [kernel-hardening] [PATCH v5 10/13] net/neighbor: use get_random_u32 for 32-bit hash random X-Virus-Scanned: ClamAV using ClamSMTP Using get_random_u32 here is faster, more fitting of the use case, and just as cryptographically secure. It also has the benefit of providing better randomness at early boot, which is when many of these structures are assigned. Signed-off-by: Jason A. Donenfeld Cc: David Miller --- net/core/neighbour.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index d274f81fcc2c..9784133b0cdb 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -312,8 +312,7 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl, struct net_device static void neigh_get_hash_rnd(u32 *x) { - get_random_bytes(x, sizeof(*x)); - *x |= 1; + *x = get_random_u32() | 1; } static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)