From patchwork Thu May 16 16:12:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 10946885 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 59CDE933 for ; Thu, 16 May 2019 16:17:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4721C28820 for ; Thu, 16 May 2019 16:17:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3B4DA289EA; Thu, 16 May 2019 16:17:34 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CCC8B28820 for ; Thu, 16 May 2019 16:17:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726481AbfEPQRd (ORCPT ); Thu, 16 May 2019 12:17:33 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:32945 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726369AbfEPQRc (ORCPT ); Thu, 16 May 2019 12:17:32 -0400 Received: from LHREML713-CAH.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id 15D88A774FA91AD2A6E8; Thu, 16 May 2019 17:17:31 +0100 (IST) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.154) by smtpsuk.huawei.com (10.201.108.36) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 16 May 2019 17:17:21 +0100 From: Roberto Sassu To: , , CC: , , , , , Roberto Sassu , Subject: [PATCH 1/4] evm: check hash algorithm passed to init_desc() Date: Thu, 16 May 2019 18:12:54 +0200 Message-ID: <20190516161257.6640-1-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.204.65.154] X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP This patch prevents memory access beyond the evm_tfm array by checking the validity of the index (hash algorithm) passed to init_desc(). The hash algorithm can be arbitrarily set if the security.ima xattr type is not EVM_XATTR_HMAC. Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures") Signed-off-by: Roberto Sassu Cc: stable@vger.kernel.org --- security/integrity/evm/evm_crypto.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index e11564eb645b..82a38e801ee4 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -89,6 +89,9 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo) tfm = &hmac_tfm; algo = evm_hmac; } else { + if (hash_algo >= HASH_ALGO__LAST) + return ERR_PTR(-EINVAL); + tfm = &evm_tfm[hash_algo]; algo = hash_algo_name[hash_algo]; }