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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B3A7EC43382 for ; Thu, 27 Sep 2018 19:17:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C2DD216C4 for ; Thu, 27 Sep 2018 19:17:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C2DD216C4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728568AbeI1BhH (ORCPT ); Thu, 27 Sep 2018 21:37:07 -0400 Received: from mga17.intel.com ([192.55.52.151]:38331 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727760AbeI1BhG (ORCPT ); Thu, 27 Sep 2018 21:37:06 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Sep 2018 12:17:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,311,1534834800"; d="scan'208";a="90082086" Received: from cschaufl-mobl.amr.corp.intel.com ([10.251.154.97]) by fmsmga002.fm.intel.com with ESMTP; 27 Sep 2018 12:17:21 -0700 From: Casey Schaufler To: kernel-hardening@lists.openwall.com, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov, casey.schaufler@intel.com, dave.hansen@intel.com, deneen.t.dock@intel.com, kristen@linux.intel.com, arjan@linux.intel.com Subject: [PATCH 6/5] capability: Repair sidechannel test in ptrace Date: Thu, 27 Sep 2018 12:17:20 -0700 Message-Id: <20180927191720.9480-1-casey.schaufler@intel.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180824224117.3356-1-casey.schaufler@intel.com> References: <20180824224117.3356-1-casey.schaufler@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Casey Schaufler The PTRACE_MODE_SCHED check erroniously returns 0 in all cases. It should be returning -EPERM. This fixes the logic to correct that error. Signed-off-by: Casey Schaufler --- security/commoncap.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index e77457110d05..70a7e3d19c16 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -152,9 +152,8 @@ int cap_ptrace_access_check(struct task_struct *child, unsigned int mode) if (cred->user_ns == child_cred->user_ns && cap_issubset(child_cred->cap_permitted, *caller_caps)) goto out; - if (mode & PTRACE_MODE_SCHED) - goto out; - if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) + if (!(mode & PTRACE_MODE_SCHED) && + ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) goto out; ret = -EPERM; out: -- 2.17.1