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

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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