From patchwork Thu Jul 15 09:17:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "tianjia.zhang" X-Patchwork-Id: 12379477 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 A645BC07E96 for ; Thu, 15 Jul 2021 09:17:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8999A60BD3 for ; Thu, 15 Jul 2021 09:17:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234002AbhGOJUT (ORCPT ); Thu, 15 Jul 2021 05:20:19 -0400 Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]:38607 "EHLO out30-57.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229620AbhGOJUT (ORCPT ); Thu, 15 Jul 2021 05:20:19 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R431e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=tianjia.zhang@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0UfsATuc_1626340644; Received: from localhost(mailfrom:tianjia.zhang@linux.alibaba.com fp:SMTPD_---0UfsATuc_1626340644) by smtp.aliyun-inc.com(127.0.0.1); Thu, 15 Jul 2021 17:17:25 +0800 From: Tianjia Zhang To: Casey Schaufler , James Morris , "Serge E. Hallyn" , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tianjia Zhang Subject: [PATCH] Smack: Fix wrong semantics in smk_access_entry() Date: Thu, 15 Jul 2021 17:17:24 +0800 Message-Id: <20210715091724.45768-1-tianjia.zhang@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.3.ge56e4f7 MIME-Version: 1.0 Precedence: bulk List-ID: In the smk_access_entry() function, if no matching rule is found in the rust_list, a negative error code will be used to perform bit operations with the MAY_ enumeration value. This is semantically wrong. This patch fixes this issue. Signed-off-by: Tianjia Zhang --- security/smack/smack_access.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 1f391f6a3d47..d2186e2757be 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -81,23 +81,22 @@ int log_policy = SMACK_AUDIT_DENIED; int smk_access_entry(char *subject_label, char *object_label, struct list_head *rule_list) { - int may = -ENOENT; struct smack_rule *srp; list_for_each_entry_rcu(srp, rule_list, list) { if (srp->smk_object->smk_known == object_label && srp->smk_subject->smk_known == subject_label) { - may = srp->smk_access; - break; + int may = srp->smk_access; + /* + * MAY_WRITE implies MAY_LOCK. + */ + if ((may & MAY_WRITE) == MAY_WRITE) + may |= MAY_LOCK; + return may; } } - /* - * MAY_WRITE implies MAY_LOCK. - */ - if ((may & MAY_WRITE) == MAY_WRITE) - may |= MAY_LOCK; - return may; + return -ENOENT; } /**