From patchwork Tue Jun 6 17:48:01 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: 9769413 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 4BF436035D for ; Tue, 6 Jun 2017 17:50:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4796626E1A for ; Tue, 6 Jun 2017 17:50:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3C3BF2842A; Tue, 6 Jun 2017 17:50:10 +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=-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 3C2AE26E1A for ; Tue, 6 Jun 2017 17:50:08 +0000 (UTC) Received: (qmail 4048 invoked by uid 550); 6 Jun 2017 17:48:50 -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 1711 invoked from network); 6 Jun 2017 17:48:32 -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=xZPxHColhWLnkOpn9xCiHK6PFGUD+KTnrLes IIc8lav4U3DmwiAn8Z8eTWFgrU5bZzasQlkz+2OpYXXUCtu35OClz8zPVfYzhyLH 2HAi+EmaY1pQjwuEZSdSYQv4LPkNuw4EWzZyLhfxrkeN/eo4iz+THJSu/K1F7yk3 IG5cTe9rCh45oXoMjW1lPgyw0qxR/iL8XGbJZftQrbjaHNkA/VNsZtiQPQMaWG/c ej8YUYqXell5VvGNVqtMaxO6lXR1ucOmpdt/YhlrD+AFku03bK36hZRVIVswM8yT 0NsdNPPX0lgv2fnTnJnsmETZgVdnluMRI5exAn9/p64ucGVdug== 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" Date: Tue, 6 Jun 2017 19:48:01 +0200 Message-Id: <20170606174804.31124-11-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 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)