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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 E3830C43387 for ; Wed, 9 Jan 2019 22:03:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B1CC6206B7 for ; Wed, 9 Jan 2019 22:03:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726773AbfAIWD1 (ORCPT ); Wed, 9 Jan 2019 17:03:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:28084 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726190AbfAIWD1 (ORCPT ); Wed, 9 Jan 2019 17:03:27 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 51D9FC0C6C1D; Wed, 9 Jan 2019 22:03:26 +0000 (UTC) Received: from workstation (ovpn-204-66.brq.redhat.com [10.40.204.66]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B19525D763; Wed, 9 Jan 2019 22:03:24 +0000 (UTC) From: Petr Lautrbach To: selinux@vger.kernel.org Cc: Stephen Smalley , jwcart2@tycho.nsa.gov Subject: Re: [PATCH v2] libsemanage: set selinux policy root around calls to selinux_boolean_sub References: <20190108134822.13184-1-sds@tycho.nsa.gov> Date: Wed, 09 Jan 2019 23:03:22 +0100 In-Reply-To: <20190108134822.13184-1-sds@tycho.nsa.gov> (Stephen Smalley's message of "Tue, 8 Jan 2019 08:48:22 -0500") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 09 Jan 2019 22:03:26 +0000 (UTC) Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Stephen Smalley writes: > As reported in #109, semodule -p /path/to/policyroot -s minimum -n -B > tries to use /etc/selinux/targeted/booleans.subs_dist. This is because > it invokes the libselinux selinux_boolean_sub() interface, which uses > the active/installed policy files rather than the libsemanage ones. > > Switch the selinux policy root around the selinux_boolean_sub() call > to incorporate the semanage root as a prefix and to use the specified > policy store as a suffix so that the correct booleans.subs_dist file > (if any) is used. > > The underlying bug is that booleans.subs_dist is not itself managed > via libsemanage. If it was managed and therefore lived within the > policy store, then libsemanage could access the appropriate > booleans.subs_dist file without using the libselinux interface at all, > and thus would not need to modify the selinux policy root. Moving > booleans.subs_dist to a managed file is deferred to a future change. > > Test: > dnf install selinux-policy-minimum selinux-policy-targeted > cd / && tar cf - etc/selinux var/lib/selinux | (cd ~/policy-root; tar xvpf -) > strace semodule -p ~/policy-root -s minimum -n -B > > Before: > openat(AT_FDCWD, "/etc/selinux/targeted/booleans.subs_dist", O_RDONLY|O_CLOEXEC) = 5 > > After: > openat(AT_FDCWD, "/home/sds/policy-root/etc/selinux/minimum/booleans.subs_dist", O_RDONLY|O_CLOEXEC) = 5 > > Fixes https://github.com/SELinuxProject/selinux/issues/109 > > Signed-off-by: Stephen Smalley Acked-by: Petr Lautrbach > --- > v2 skips setting of the policy root if they already match, introduces a > hidden prototype and definition for internal callers of semanage_root(), > and tests that selinux_policy_root() is non-NULL before strdup'ing it. > libsemanage/src/boolean_record.c | 54 +++++++++++++++++++++++++++++-- > libsemanage/src/handle.c | 2 ++ > libsemanage/src/handle_internal.h | 9 +++--- > 3 files changed, 59 insertions(+), 6 deletions(-) > > diff --git a/libsemanage/src/boolean_record.c b/libsemanage/src/boolean_record.c > index 665c0223..c234094e 100644 > --- a/libsemanage/src/boolean_record.c > +++ b/libsemanage/src/boolean_record.c > @@ -6,7 +6,9 @@ > * Implements: record_key_t (Database Record Key) > */ > > +#include > #include > +#include "handle_internal.h" > > typedef sepol_bool_t semanage_bool_t; > typedef sepol_bool_key_t semanage_bool_key_t; > @@ -84,10 +86,58 @@ hidden_def(semanage_bool_get_name) > int semanage_bool_set_name(semanage_handle_t * handle, > semanage_bool_t * boolean, const char *name) > { > - int rc; > - char *subname = selinux_boolean_sub(name); > + int rc = -1; > + const char *prefix = semanage_root(); > + const char *storename = handle->conf->store_path; > + const char *selinux_root = selinux_policy_root(); > + char *oldroot; > + char *olddir; > + char *subname = NULL; > + char *newroot = NULL; > + char *end; > + > + if (!selinux_root) > + return -1; > + > + oldroot = strdup(selinux_root); > + if (!oldroot) > + return -1; > + olddir = strdup(oldroot); > + if (!olddir) > + goto out; > + end = strrchr(olddir, '/'); > + if (!end) > + goto out; > + end++; > + *end = '\0'; > + rc = asprintf(&newroot, "%s%s%s", prefix, olddir, storename); > + if (rc < 0) > + goto out; > + > + if (strcmp(oldroot, newroot)) { > + rc = selinux_set_policy_root(newroot); > + if (rc) > + goto out; > + } > + > + subname = selinux_boolean_sub(name); > + if (!subname) { > + rc = -1; > + goto out; > + } > + > + if (strcmp(oldroot, newroot)) { > + rc = selinux_set_policy_root(oldroot); > + if (rc) > + goto out; > + } > + > rc = sepol_bool_set_name(handle->sepolh, boolean, subname); > +out: > free(subname); > + free(oldroot); > + free(olddir); > + free(newroot); > return rc; > } > > diff --git a/libsemanage/src/handle.c b/libsemanage/src/handle.c > index a6567bd4..e5109aef 100644 > --- a/libsemanage/src/handle.c > +++ b/libsemanage/src/handle.c > @@ -58,6 +58,8 @@ const char * semanage_root(void) > return private_semanage_root; > } > > +hidden_def(semanage_root); > + > semanage_handle_t *semanage_handle_create(void) > { > semanage_handle_t *sh = NULL; > diff --git a/libsemanage/src/handle_internal.h b/libsemanage/src/handle_internal.h > index 66ce2708..d4b4d9c7 100644 > --- a/libsemanage/src/handle_internal.h > +++ b/libsemanage/src/handle_internal.h > @@ -5,8 +5,9 @@ > #include "dso.h" > > hidden_proto(semanage_begin_transaction) > - hidden_proto(semanage_handle_destroy) > - hidden_proto(semanage_reload_policy) > - hidden_proto(semanage_access_check) > - hidden_proto(semanage_set_root) > +hidden_proto(semanage_handle_destroy) > +hidden_proto(semanage_reload_policy) > +hidden_proto(semanage_access_check) > +hidden_proto(semanage_set_root) > +hidden_proto(semanage_root) > #endif