From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754947AbdJLBAI (ORCPT ); Wed, 11 Oct 2017 21:00:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60486 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753190AbdJLA7B (ORCPT ); Wed, 11 Oct 2017 20:59:01 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8714B806AC Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=rgb@redhat.com From: Richard Guy Briggs To: linux-security-module@vger.kernel.org, linux-audit@redhat.com, linux-kernel@vger.kernel.org Cc: Richard Guy Briggs , Kees Cook , Andy Lutomirski , "Serge E . Hallyn" , James Morris , Paul Moore , Steve Grubb , Eric Paris Subject: [PATCH GHAK16 V5 06/10] capabilities: move audit log decision to function Date: Wed, 11 Oct 2017 20:57:10 -0400 Message-Id: <9d2c4b37a1c7e6d9c58aff48037a0058cd2eff01.1507769413.git.rgb@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 12 Oct 2017 00:59:01 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Acked-by: Kees Cook Okay-ished-by: Paul Moore --- security/commoncap.c | 50 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 30 insertions(+), 20 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index 421f743..d7f0cbd 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -765,6 +765,32 @@ 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 @@ -841,26 +867,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) if (WARN_ON(!cap_ambient_invariant_ok(new))) return -EPERM; - /* - * 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); -- 1.8.3.1