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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA7AECDB474 for ; Mon, 23 Oct 2023 11:50:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234592AbjJWLuR (ORCPT ); Mon, 23 Oct 2023 07:50:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234594AbjJWLuQ (ORCPT ); Mon, 23 Oct 2023 07:50:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85435AF for ; Mon, 23 Oct 2023 04:50:14 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1C46C433C7; Mon, 23 Oct 2023 11:50:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698061814; bh=Alw5F36ufth/ukSgpv5yhVd9ocFRWLYuGb3EU8JQQ88=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JIWVcDmpiHi/aNccQH3FiSNgNmg9ddxnwGYdadrx3tZkycoXLIC1HJLJIo4/1+/JV 85U9aK9rjjwoCDHJrMi5Z4ZMgqlpT2ivk/TySnFctj6dSed63lyEy4xQiINn6qUh3Y fgJBGHntwgoSayivlJmLO77KoGUjTpAk05Sddkt4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 5.10 173/202] Bluetooth: hci_event: Fix using memcmp when comparing keys Date: Mon, 23 Oct 2023 12:58:00 +0200 Message-ID: <20231023104831.536043221@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104826.569169691@linuxfoundation.org> References: <20231023104826.569169691@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Luiz Augusto von Dentz [ Upstream commit b541260615f601ae1b5d6d0cc54e790de706303b ] memcmp is not consider safe to use with cryptographic secrets: 'Do not use memcmp() to compare security critical data, such as cryptographic secrets, because the required CPU time depends on the number of equal bytes.' While usage of memcmp for ZERO_KEY may not be considered a security critical data, it can lead to more usage of memcmp with pairing keys which could introduce more security problems. Fixes: 455c2ff0a558 ("Bluetooth: Fix BR/EDR out-of-band pairing with only initiator data") Fixes: 33155c4aae52 ("Bluetooth: hci_event: Ignore NULL link key") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/hci_event.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index c0a2103241415..ad5294de97594 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -25,6 +25,8 @@ /* Bluetooth HCI event handling. */ #include +#include +#include #include #include @@ -4076,7 +4078,7 @@ static void hci_link_key_notify_evt(struct hci_dev *hdev, struct sk_buff *skb) goto unlock; /* Ignore NULL link key against CVE-2020-26555 */ - if (!memcmp(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) { + if (!crypto_memneq(ev->link_key, ZERO_KEY, HCI_LINK_KEY_SIZE)) { bt_dev_dbg(hdev, "Ignore NULL link key (ZERO KEY) for %pMR", &ev->bdaddr); hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE); @@ -4588,8 +4590,8 @@ static u8 bredr_oob_data_present(struct hci_conn *conn) * available, then do not declare that OOB data is * present. */ - if (!memcmp(data->rand256, ZERO_KEY, 16) || - !memcmp(data->hash256, ZERO_KEY, 16)) + if (!crypto_memneq(data->rand256, ZERO_KEY, 16) || + !crypto_memneq(data->hash256, ZERO_KEY, 16)) return 0x00; return 0x02; @@ -4599,8 +4601,8 @@ static u8 bredr_oob_data_present(struct hci_conn *conn) * not supported by the hardware, then check that if * P-192 data values are present. */ - if (!memcmp(data->rand192, ZERO_KEY, 16) || - !memcmp(data->hash192, ZERO_KEY, 16)) + if (!crypto_memneq(data->rand192, ZERO_KEY, 16) || + !crypto_memneq(data->hash192, ZERO_KEY, 16)) return 0x00; return 0x01; -- 2.40.1