From e991859590d4b598193f192674fca0ded1914bae Mon Sep 17 00:00:00 2001
From: Jakub Hrozek <jhrozek@redhat.com>
Date: Fri, 13 Feb 2015 17:57:35 +0100
Subject: [PATCH 16/17] selinux: Delete existing user mapping on empty default
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https://fedorahosted.org/sssd/ticket/2587

The case of SELinux default user mapping being an empty string is valid,
it should translate into "pick the default context on the target
machine".

In case the context is empty, we need to delete the per-user mapping from
the SELinux database to make sure the default is used.

Reviewed-by: Michal Židek <mzidek@redhat.com>
Reviewed-by: Pavel Reichl <preichl@redhat.com>
(cherry picked from commit 01f78f755fde63997ccfded71fb8395569b11430)
---
 src/providers/ipa/ipa_selinux.c   | 14 ++++++++------
 src/providers/ipa/selinux_child.c | 10 +++++++++-
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/providers/ipa/ipa_selinux.c b/src/providers/ipa/ipa_selinux.c
index f7e17c97f0bf8d6c64eb045c3bc954da8eb3d568..00c793a2643b51e59884730fa4f0ba3c7ed1bea6 100644
--- a/src/providers/ipa/ipa_selinux.c
+++ b/src/providers/ipa/ipa_selinux.c
@@ -749,7 +749,7 @@ static errno_t choose_best_seuser(TALLOC_CTX *mem_ctx,
 
     /* If no maps match, we'll use the default SELinux user from the
      * config */
-    seuser_mls_str = talloc_strdup(tmp_ctx, default_user);
+    seuser_mls_str = talloc_strdup(tmp_ctx, default_user ? default_user : "");
     if (seuser_mls_str == NULL) {
         ret = ENOMEM;
         goto done;
@@ -1373,11 +1373,13 @@ ipa_get_selinux_maps_offline(struct tevent_req *req)
         return ENOMEM;
     }
 
-    ret = sysdb_attrs_add_string(state->defaults,
-                                 IPA_CONFIG_SELINUX_DEFAULT_USER_CTX,
-                                 default_user);
-    if (ret != EOK) {
-        return ret;
+    if (default_user) {
+        ret = sysdb_attrs_add_string(state->defaults,
+                                    IPA_CONFIG_SELINUX_DEFAULT_USER_CTX,
+                                    default_user);
+        if (ret != EOK) {
+            return ret;
+        }
     }
 
     ret = sysdb_attrs_add_string(state->defaults,
diff --git a/src/providers/ipa/selinux_child.c b/src/providers/ipa/selinux_child.c
index 63d4b929786d4b8cc0d40f0c65009673c7309094..3756557a5e28624e6437e805ca8a387d2f65dd1f 100644
--- a/src/providers/ipa/selinux_child.c
+++ b/src/providers/ipa/selinux_child.c
@@ -146,7 +146,15 @@ static int sc_set_seuser(const char *login_name, const char *seuser_name,
      * the directories are created with the expected permissions
      */
     old_mask = umask(0);
-    ret = set_seuser(login_name, seuser_name, mls);
+    if (strcmp(seuser_name, "") == 0) {
+        /* An empty SELinux user should cause SSSD to use the system
+         * default. We need to remove the SELinux user from the DB
+         * in that case
+         */
+        ret = del_seuser(login_name);
+    } else {
+        ret = set_seuser(login_name, seuser_name, mls);
+    }
     umask(old_mask);
     return ret;
 }
-- 
2.3.3