From patchwork Tue Jun 6 00:51:05 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: 9767761 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 9075A6034B for ; Tue, 6 Jun 2017 00:52:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8726127968 for ; Tue, 6 Jun 2017 00:52:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7BE2A283C0; Tue, 6 Jun 2017 00:52:51 +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 9844827968 for ; Tue, 6 Jun 2017 00:52:50 +0000 (UTC) Received: (qmail 21578 invoked by uid 550); 6 Jun 2017 00:52:16 -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 18286 invoked from network); 6 Jun 2017 00:52:03 -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=UK6ckHHiSjKMV4QOHaNycZ5vwg31pql9XVLq b0aFpjgVjzEGISrzEVljv9adNu2hlfQSSmwW12+nfy35Zy4bAMIDhhBWZhN76NZZ 2KvA7ZWhNTB0a+XnJ+9EHAEXw+v7YBtdTNBHJLrlNBWTudaIFcaEJs3tn5HDBNwn 5xb5FIgiq17I0vB/FbZp+yZFWSgm7hhFi/950UCz8FgJ+/ySHDb+3SaADwttAQ52 6ea76WYBB8D7lLyc2oaBXuUjfqEJ3A2EmshuC5LpdWvOeNAcfrrHDm5y/Ihulcwy u6+Wlz8zid2GvTrAKjI5P9FYZDwvg0Og9L2orOn0Hs3zSJ3Mmg== From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , David Miller Cc: "Jason A. Donenfeld" Date: Tue, 6 Jun 2017 02:51:05 +0200 Message-Id: <20170606005108.5646-11-Jason@zx2c4.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170606005108.5646-1-Jason@zx2c4.com> References: <20170606005108.5646-1-Jason@zx2c4.com> Subject: [kernel-hardening] [PATCH v3 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)