sandbox: fix file labels on copied files

Since python 3.3, shutil.copy2() tries to preserve extended file
system attributes. It means that when a user uses -i or -I, copied files
have the original labels and sandboxed process can't read them.

With this change, homedir and tmpdir is recursively relabeled with the
expected sandbox labels after all items are in their place.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1294020

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>

policycoreutils/sandbox/sandbox

@@ -425,21 +425,20 @@ sandbox [-h] [-l level ] [-[X|M] [-H homedir] [-T tempdir]] [-I includefile ] [-
         self.__filecon = "%s:object_r:sandbox_file_t:%s" % (con[0], level)
 
     def __setup_dir(self):
+        selinux.setfscreatecon(self.__filecon)
         if self.__options.homedir:
-            selinux.chcon(self.__options.homedir, self.__filecon, recursive=True)
             self.__homedir = self.__options.homedir
         else:
-            selinux.setfscreatecon(self.__filecon)
             self.__homedir = mkdtemp(dir="/tmp", prefix=".sandbox_home_")
 
         if self.__options.tmpdir:
-            selinux.chcon(self.__options.tmpdir, self.__filecon, recursive=True)
             self.__tmpdir = self.__options.tmpdir
         else:
-            selinux.setfscreatecon(self.__filecon)
             self.__tmpdir = mkdtemp(dir="/tmp", prefix=".sandbox_tmp_")
-        selinux.setfscreatecon(None)
         self.__copyfiles()
+        selinux.chcon(self.__homedir, self.__filecon, recursive=True)
+        selinux.chcon(self.__tmpdir, self.__filecon, recursive=True)
+        selinux.setfscreatecon(None)
 
     def __execute(self):
         try:

policycoreutils/sandbox/test_sandbox.py

@@ -97,6 +97,14 @@ class SandboxTests(unittest.TestCase):
         shutil.rmtree(tmpdir)
         self.assertSuccess(p.returncode, err)
 
+    def test_include_file(self):
+        "Verify that sandbox can copy a file in the sandbox home and use it"
+        p = Popen([sys.executable, 'sandbox', '-i' ,'test_sandbox.py' , '-M', '/bin/cat', 'test_sandbox.py'],
+                  stdout=PIPE, stderr=PIPE)
+        out, err = p.communicate()
+        self.assertSuccess(p.returncode, err)
+
+
 if __name__ == "__main__":
     import selinux
     if selinux.security_getenforce() == 1: