From patchwork Fri Jun 19 14:33:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 223682 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=unavailable 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 31C08C433E1 for ; Fri, 19 Jun 2020 16:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F416C206B7 for ; Fri, 19 Jun 2020 16:44:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592585043; bh=r2ROIZwUqadhDJcWqs6JlrkoQibYz2+c8Uco5Az4U7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=e4mRFnvBh/EZEBgaD927jaOdqO3+7l3KDCUrw8EK0LXZnMtEBQyn1pclYJ7X/Pw1r +rX7LfaaK15J3xtCpxRcNwdJr0FVknsOOytO1kijQelyFOZvLWmeezE0lPxLMhorWJ qduwUgUlCI7tDE/Gx7aE0oxc1c0TcsZ7lxpUdsMk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388750AbgFSQn1 (ORCPT ); Fri, 19 Jun 2020 12:43:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:34412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387899AbgFSOna (ORCPT ); Fri, 19 Jun 2020 10:43:30 -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 2BCFC21556; Fri, 19 Jun 2020 14:43:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592577809; bh=r2ROIZwUqadhDJcWqs6JlrkoQibYz2+c8Uco5Az4U7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vBQnrQ8/DequWvtPllRLInpDAAm/nPcuRcaJaqphqyFF837DNKC02CF503lZkr7JO qDcrKWpd3nL3hy9Gp6jooOcDtmMeRjsTYUtu59vbJkisjYaeBhcVauibrkFijqupxG LaJWc/90RxaNV3zz3f5jOPL/Aa7PyjmNzcCQJsBk= 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 4.9 099/128] ima: Fix ima digest hash table key calculation Date: Fri, 19 Jun 2020 16:33:13 +0200 Message-Id: <20200619141625.362961745@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141620.148019466@linuxfoundation.org> References: <20200619141620.148019466@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -136,9 +136,10 @@ 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; } enum ima_hooks {