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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 CD242C433E0 for ; Fri, 19 Jun 2020 16:02:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1F76207FC for ; Fri, 19 Jun 2020 16:02:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592582563; bh=MDzcFnPU6/OGUZX8eSnSRt/nxMi9RAZ+guKmqLWOiNA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VFWtCA+SaPw9UfHq7OPgT1SibSjsfengSUxY8/4BsEHUAlkcHs621RAcgQZAR/QJC 4HCPz6rPnxpnpdHgvFoOnfLBBLTAzQjoXuhVWW4ylHzF42x4vJ57biBkFhPLZCc55y Ie6LcinU6fYuXcHLiGcD/s76I5jmM/QOM56xU32k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403895AbgFSPM3 (ORCPT ); Fri, 19 Jun 2020 11:12:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:42850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392159AbgFSPMW (ORCPT ); Fri, 19 Jun 2020 11:12:22 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02A6120776; Fri, 19 Jun 2020 15:12:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592579541; bh=MDzcFnPU6/OGUZX8eSnSRt/nxMi9RAZ+guKmqLWOiNA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pXnncCH0zYDrr+4HwBkKvZWE7XurVL9LqiviyE/byuO39COkmA/Zy2cBCFDxZUhyh YkxJuSOOBpjI0sX8pfPW+TAq7sa7NaZmc8ypmLWIAoGEW9pjrL24zd9Ai3gDSnwWf6 bgg80Y8tmZohDroE1Kf7IeDdinbqaIVK7F5UQTiQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Roberto Sassu , Krzysztof Struczynski , David.Laight@aculab.com (big endian system concerns), Mimi Zohar Subject: [PATCH 5.4 174/261] ima: Fix ima digest hash table key calculation Date: Fri, 19 Jun 2020 16:33:05 +0200 Message-Id: <20200619141658.259471735@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141649.878808811@linuxfoundation.org> References: <20200619141649.878808811@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Krzysztof Struczynski commit 1129d31b55d509f15e72dc68e4b5c3a4d7b4da8d upstream. Function hash_long() accepts unsigned long, while currently only one byte is passed from ima_hash_key(), which calculates a key for ima_htable. Given that hashing the digest does not give clear benefits compared to using the digest itself, remove hash_long() and return the modulus calculated on the first two bytes of the digest with the number of slots. Also reduce the depth of the hash table by doubling the number of slots. Cc: stable@vger.kernel.org Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider") Co-developed-by: Roberto Sassu Signed-off-by: Roberto Sassu Signed-off-by: Krzysztof Struczynski Acked-by: David.Laight@aculab.com (big endian system concerns) Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman --- security/integrity/ima/ima.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -36,7 +36,7 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = #define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE #define IMA_EVENT_NAME_LEN_MAX 255 -#define IMA_HASH_BITS 9 +#define IMA_HASH_BITS 10 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS) #define IMA_TEMPLATE_FIELD_ID_MAX_LEN 16 @@ -175,9 +175,10 @@ struct ima_h_table { }; extern struct ima_h_table ima_htable; -static inline unsigned long ima_hash_key(u8 *digest) +static inline unsigned int ima_hash_key(u8 *digest) { - return hash_long(*digest, IMA_HASH_BITS); + /* there is no point in taking a hash of part of a digest */ + return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE; } #define __ima_hooks(hook) \