From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69F32C4361B for ; Mon, 7 Dec 2020 17:50:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3908C21D42 for ; Mon, 7 Dec 2020 17:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726359AbgLGRut (ORCPT ); Mon, 7 Dec 2020 12:50:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725994AbgLGRut (ORCPT ); Mon, 7 Dec 2020 12:50:49 -0500 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBA09C061749; Mon, 7 Dec 2020 09:50:08 -0800 (PST) Received: by mail-pf1-x444.google.com with SMTP id c79so10780741pfc.2; Mon, 07 Dec 2020 09:50:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fUh+4z+VG104kmWgXIS5rqWmBazf/fgwAB8pUJ1DNuA=; b=UlrCb3xvzoJdzfZ/x97NJoC+q5KmaKK5qmIm/e9mnRKf4ruOBR8zuVbm3I64wvyd89 I5PLl4yG4mZaoF2h2sAcMIyHlA2UeoMv+OPzrXMdxrNEyUb1+I2trvKE8BQjMEkc4oId thTDnk4SxHBflzpt7BDQRIq0Fl7mHODojBX+pDx42WkfhKACy38gyASMcgfeLYN90MZa Wh6uDrHMNCu7zjondL0zE+tTyOUOxx7sz49NeDSQE5QA/y0h63/QeeQSn/CwYSA5Q6V0 XtC5hvOizHVQzChRHFgDobP1LMT8k3mV++VFdJeP0+wbTOI/AFDTTz6Dr1ewWVGtog5s kGqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fUh+4z+VG104kmWgXIS5rqWmBazf/fgwAB8pUJ1DNuA=; b=Qi27/ZDu9DaqzmOWevXVcl5bi6k6TPfgmRF6iwMXKkGaeKitlpkmiDXFjnzdLIHR4P 2uLRvIZo5QqiTnm/F/bBZv9dKFt0ic2YneK6e3G1/phmc1GNkGSnPPGeLLG2gVsVZ1ue LBr9sEeQLQxfSrlYYGelN+J751PSLZq+wSsrCov2X+g9m0RDAWrdcLyxr41o7Gv5WPnO cj/39tMZu4GLx4/b+ZAfTFLRVMv27IPCW/rKN+upaf2pkoqiyvSVKoJU0vLxWzi0lq1C O18uj5f2k8XuvrE4H3PUiRzu0pL9lqrRWt0nAODc6EtCzUIlvDZGy3+BY+vOih4XKh3u fu7g== X-Gm-Message-State: AOAM532AmMSODgS+nMO6uhlHtlKcG0V4EVBdUcRXVy9sEJOWZ39s5dMV qJvDt5gkbC/jdklyC1xsBJ8= X-Google-Smtp-Source: ABdhPJwBijIrVQscb6Ya9OufTg3mUKcb0mMt8o0C3jf0JEr+I1L3N8iMAzO6A6Ux6a/QtxvY99NvIg== X-Received: by 2002:a17:902:8b8c:b029:d8:de6f:ed35 with SMTP id ay12-20020a1709028b8cb02900d8de6fed35mr17502376plb.36.1607363408343; Mon, 07 Dec 2020 09:50:08 -0800 (PST) Received: from DESKTOP-6EISONM.localdomain ([143.248.2.153]) by smtp.gmail.com with ESMTPSA id mr7sm11173651pjb.31.2020.12.07.09.50.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Dec 2020 09:50:07 -0800 (PST) From: Mincheol Son To: marcel@holtmann.org Cc: johan.hedberg@gmail.com, davem@davemloft.net, kuba@kernel.org, linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Mincheol Son Subject: [PATCH] Bluetooth: smp: Fix biased random passkey generation Date: Tue, 8 Dec 2020 02:49:57 +0900 Message-Id: <20201207174957.408-1-encrypted.def@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since u32 range size is not a multiple of 1,000,000, current passkey generation logic is biased. Fixed this by adding a routine that selects passkey again if passkey is 4,200,000,000 or more. Signed-off-by: Mincheol Son --- net/bluetooth/smp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index c659c464f7ca..26ed83e0db34 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -922,7 +922,9 @@ static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, /* Generate random passkey. */ if (smp->method == CFM_PASSKEY) { memset(smp->tk, 0, sizeof(smp->tk)); - get_random_bytes(&passkey, sizeof(passkey)); + do { + get_random_bytes(&passkey, sizeof(passkey)); + } while (passkey >= (u32)4200000000); passkey %= 1000000; put_unaligned_le32(passkey, smp->tk); BT_DBG("PassKey: %d", passkey); -- 2.25.1