From patchwork Tue Jun 6 17:48:00 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: 9769421 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 22B216035D for ; Tue, 6 Jun 2017 17:50:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1F2FD223A6 for ; Tue, 6 Jun 2017 17:50:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 13E2927E63; Tue, 6 Jun 2017 17:50:30 +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 14FD6223A6 for ; Tue, 6 Jun 2017 17:50:27 +0000 (UTC) Received: (qmail 5217 invoked by uid 550); 6 Jun 2017 17:48:53 -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 1691 invoked from network); 6 Jun 2017 17:48:31 -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=+uHz Y+Igq9iWBc3OsU2692oV8m8=; b=0wVaZx43W6aEyHjeDQCGKIZ/oCui/tA+njm7 RWahBU8UXYJ99bNUov/6sPpJCRH1GjFHyfJC+IJWhbqoKnD8zyfO5rRJlRyVmsh5 LEap6lCdcr1a5ym3B/mRlmFXwfWdA0aigQtKVOSlvB0MpjaUnD00k02ojQsMeG2/ 9sS1Pt+2snlsO7xYIIT4/GyAcKTt9qDaE9MLelm032eyySvCR7JCUk78nwkoSb4Y BY+Ns6eefFSdHkU1nbjZGPTpBI6d/36h8xasdFoey5ubwYyNDjJXJDW/oc/YIXVZ Y0lsdEj1IylMzcJRduB+9isgshjV7+a90gJca6v9ALeSxWRX4Q== 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" , Thomas Graf , Herbert Xu Date: Tue, 6 Jun 2017 19:48:00 +0200 Message-Id: <20170606174804.31124-10-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 09/13] rhashtable: use get_random_u32 for hash_rnd X-Virus-Scanned: ClamAV using ClamSMTP This is much faster and just as secure. It also has the added benefit of probably returning better randomness at early-boot on systems with architectural RNGs. Signed-off-by: Jason A. Donenfeld Cc: Thomas Graf Cc: Herbert Xu --- lib/rhashtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/rhashtable.c b/lib/rhashtable.c index d9e7274a04cd..a1eb7c947f46 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -235,7 +235,7 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht, INIT_LIST_HEAD(&tbl->walkers); - get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd)); + tbl->hash_rnd = get_random_u32(); for (i = 0; i < nbuckets; i++) INIT_RHT_NULLS_HEAD(tbl->buckets[i], ht, i);