From patchwork Wed Aug 23 10:12:57 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Guy Briggs X-Patchwork-Id: 9917045 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 77E4960327 for ; Wed, 23 Aug 2017 10:13:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A8EF288B6 for ; Wed, 23 Aug 2017 10:13:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5F6AB2893D; Wed, 23 Aug 2017 10:13:58 +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 CABD2288B6 for ; Wed, 23 Aug 2017 10:13:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753855AbdHWKN5 (ORCPT ); Wed, 23 Aug 2017 06:13:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47602 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753606AbdHWKN4 (ORCPT ); Wed, 23 Aug 2017 06:13:56 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AD7FDC05683F; Wed, 23 Aug 2017 10:13:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com AD7FDC05683F Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=rgb@redhat.com Received: from madcap2.tricolour.ca (ovpn-112-7.rdu2.redhat.com [10.10.112.7]) by smtp.corp.redhat.com (Postfix) with ESMTP id 23FB663750; Wed, 23 Aug 2017 10:13:53 +0000 (UTC) From: Richard Guy Briggs To: linux-security-module@vger.kernel.org, linux-audit@redhat.com Cc: Richard Guy Briggs , Andy Lutomirski , "Serge E. Hallyn" , Kees Cook , James Morris , Eric Paris , Paul Moore , Steve Grubb Subject: [PATCH V3 06/10] capabilities: move audit log decision to function Date: Wed, 23 Aug 2017 06:12:57 -0400 Message-Id: <0ef18e4236773f4ccd55f9b47639adb6a992d104.1503459890.git.rgb@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 23 Aug 2017 10:13:56 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Move the audit log decision logic to its own function to isolate the complexity in one place. Suggested-by: Serge Hallyn Signed-off-by: Richard Guy Briggs Reviewed-by: Serge Hallyn Acked-by: James Morris --- security/commoncap.c | 50 ++++++++++++++++++++++++++++++-------------------- 1 files changed, 30 insertions(+), 20 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index 1af7dec..5d81354 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -535,6 +535,32 @@ static inline bool is_setuid(struct cred *new, const struct cred *old) static inline bool is_setgid(struct cred *new, const struct cred *old) { return !gid_eq(new->egid, old->gid); } +/* + * Audit candidate if current->cap_effective is set + * + * We do not bother to audit if 3 things are true: + * 1) cap_effective has all caps + * 2) we are root + * 3) root is supposed to have all caps (SECURE_NOROOT) + * Since this is just a normal root execing a process. + * + * Number 1 above might fail if you don't have a full bset, but I think + * that is interesting information to audit. + */ +static inline bool nonroot_raised_pE(struct cred *cred, kuid_t root) +{ + bool ret = false; + + if (cap_grew(effective, ambient, cred)) { + if (!cap_full(effective, cred) || + !is_eff(root, cred) || !is_real(root, cred) || + !root_privileged()) { + ret = true; + } + } + return ret; +} + /** * cap_bprm_set_creds - Set up the proposed credentials for execve(). * @bprm: The execution parameters, including the proposed creds @@ -614,26 +640,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) bprm->cap_effective = effective; - /* - * Audit candidate if current->cap_effective is set - * - * We do not bother to audit if 3 things are true: - * 1) cap_effective has all caps - * 2) we are root - * 3) root is supposed to have all caps (SECURE_NOROOT) - * Since this is just a normal root execing a process. - * - * Number 1 above might fail if you don't have a full bset, but I think - * that is interesting information to audit. - */ - if (cap_grew(effective, ambient, new)) { - if (!cap_full(effective, new) || - !is_eff(root_uid, new) || !is_real(root_uid, new) || - !root_privileged()) { - ret = audit_log_bprm_fcaps(bprm, new, old); - if (ret < 0) - return ret; - } + if (nonroot_raised_pE(new, root_uid)) { + ret = audit_log_bprm_fcaps(bprm, new, old); + if (ret < 0) + return ret; } new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);