From 8db75e9ebbdaec1dde836380ca38d8cfec61cf3d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20=C5=BDidek?= <mzidek@redhat.com>
Date: Thu, 1 Feb 2018 11:34:21 +0100
Subject: [PATCH 204/205] SELINUX: Check if SELinux is managed in selinux_child
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
If SELinux policy is not managed at all, don't call any SELinux user
handling functions and instead return that no update is needed.
Pair-Programmed-With: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>
Resolves:
https://pagure.io/SSSD/sssd/issue/3618
(cherry picked from commit 450b472a68abf442479755c7916c757907b35ea5)
---
src/providers/ipa/selinux_child.c | 3 +-
src/util/sss_semanage.c | 82 +++++++++++++++++++++++++++++++--------
src/util/util.h | 3 ++
3 files changed, 70 insertions(+), 18 deletions(-)
diff --git a/src/providers/ipa/selinux_child.c b/src/providers/ipa/selinux_child.c
index 073475094ee491bd5453898c6ba65214fa14fe59..bc9460e122ce991087a744fd5335e6c468c6a64b 100644
--- a/src/providers/ipa/selinux_child.c
+++ b/src/providers/ipa/selinux_child.c
@@ -27,7 +27,6 @@
#include <unistd.h>
#include <sys/stat.h>
#include <popt.h>
-#include <selinux/selinux.h>
#include "util/util.h"
#include "util/child_common.h"
@@ -173,7 +172,7 @@ static bool seuser_needs_update(struct input_buffer *ibuf)
char *db_mls_range = NULL;
errno_t ret;
- ret = getseuserbyname(ibuf->username, &db_seuser, &db_mls_range);
+ ret = sss_get_seuser(ibuf->username, &db_seuser, &db_mls_range);
DEBUG(SSSDBG_TRACE_INTERNAL,
"getseuserbyname: ret: %d seuser: %s mls: %s\n",
ret, db_seuser ? db_seuser : "unknown",
diff --git a/src/util/sss_semanage.c b/src/util/sss_semanage.c
index 37278cc986a1ea49dc2218a635d52b9d54ca089d..25b6bcdad2ad7e7ac710497f13d6a6e22360b0dd 100644
--- a/src/util/sss_semanage.c
+++ b/src/util/sss_semanage.c
@@ -22,8 +22,9 @@
#include "config.h"
#include <stdio.h>
-#ifdef HAVE_SEMANAGE
+#if defined(HAVE_SEMANAGE) && defined(HAVE_SELINUX)
#include <semanage/semanage.h>
+#include <selinux/selinux.h>
#endif
#include "util/util.h"
@@ -32,7 +33,7 @@
#define DEFAULT_SERANGE "s0"
#endif
-#ifdef HAVE_SEMANAGE
+#if defined(HAVE_SEMANAGE) && defined(HAVE_SELINUX)
/* turn libselinux messages into SSSD DEBUG() calls */
static void sss_semanage_error_callback(void *varg,
semanage_handle_t *handle,
@@ -73,33 +74,47 @@ static void sss_semanage_close(semanage_handle_t *handle)
semanage_handle_destroy(handle);
}
-static int sss_semanage_init(semanage_handle_t **_handle)
+static int sss_is_selinux_managed(semanage_handle_t *handle)
{
int ret;
- semanage_handle_t *handle = NULL;
- handle = semanage_handle_create();
- if (!handle) {
- DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create SELinux management handle\n");
- ret = EIO;
- goto done;
+ if (handle == NULL) {
+ return EINVAL;
}
- semanage_msg_set_callback(handle,
- sss_semanage_error_callback,
- NULL);
-
ret = semanage_is_managed(handle);
if (ret == 0) {
DEBUG(SSSDBG_TRACE_FUNC, "SELinux policy not managed via libsemanage\n");
- ret = ERR_SELINUX_NOT_MANAGED;
- goto done;
+ return ERR_SELINUX_NOT_MANAGED;
} else if (ret == -1) {
DEBUG(SSSDBG_CRIT_FAILURE, "Call to semanage_is_managed failed\n");
+ return EIO;
+ }
+
+ return EOK;
+}
+
+static int sss_semanage_init(semanage_handle_t **_handle)
+{
+ int ret;
+ semanage_handle_t *handle = NULL;
+
+ handle = semanage_handle_create();
+ if (!handle) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create SELinux management handle\n");
ret = EIO;
goto done;
}
+ semanage_msg_set_callback(handle,
+ sss_semanage_error_callback,
+ NULL);
+
+ ret = sss_is_selinux_managed(handle);
+ if (ret != EOK) {
+ goto done;
+ }
+
ret = semanage_access_check(handle);
if (ret < SEMANAGE_CAN_READ) {
DEBUG(SSSDBG_CRIT_FAILURE, "Cannot read SELinux policy store\n");
@@ -229,6 +244,34 @@ done:
return ret;
}
+int sss_get_seuser(const char *linuxuser,
+ char **selinuxuser,
+ char **level)
+{
+ int ret;
+ semanage_handle_t *handle;
+
+ handle = semanage_handle_create();
+ if (handle == NULL) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create SELinux management handle\n");
+ return EIO;
+ }
+
+ semanage_msg_set_callback(handle,
+ sss_semanage_error_callback,
+ NULL);
+
+ /* We only needed the handle for this call. Close the handle right
+ * after it */
+ ret = sss_is_selinux_managed(handle);
+ sss_semanage_close(handle);
+ if (ret != EOK) {
+ return ret;
+ }
+
+ return getseuserbyname(linuxuser, selinuxuser, level);
+}
+
int set_seuser(const char *login_name, const char *seuser_name,
const char *mls)
{
@@ -382,7 +425,7 @@ done:
sss_semanage_close(handle);
return ret;
}
-#else /* HAVE_SEMANAGE */
+#else /* HAVE_SEMANAGE && HAVE_SELINUX */
int set_seuser(const char *login_name, const char *seuser_name,
const char *mls)
{
@@ -393,4 +436,11 @@ int del_seuser(const char *login_name)
{
return EOK;
}
+
+int sss_get_seuser(const char *linuxuser,
+ char **selinuxuser,
+ char **level)
+{
+ return EOK;
+}
#endif /* HAVE_SEMANAGE */
diff --git a/src/util/util.h b/src/util/util.h
index 1719d8eec1b6b05877b9be3382589e442bff85be..74ce2dcecfe17d1cea96cfb5c4b7edb8fd46f09f 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -658,6 +658,9 @@ errno_t restore_creds(struct sss_creds *saved_creds);
int set_seuser(const char *login_name, const char *seuser_name,
const char *mlsrange);
int del_seuser(const char *login_name);
+int sss_get_seuser(const char *linuxuser,
+ char **selinuxuser,
+ char **level);
/* convert time from generalized form to unix time */
errno_t sss_utc_to_time_t(const char *str, const char *format, time_t *unix_time);
--
2.14.3