[apparmor] [PATCH 3/3] utils: Basic support for pivot_root rules

Tyler Hicks tyhicks at canonical.com
Thu Apr 3 19:56:01 UTC 2014


Bug: https://bugs.launchpad.net/bugs/1298678

This patch does bare bones parsing of pivot_root rules and stores the raw
strings for writing them out later. It is meant to be a simple change to
prevent aa.py from emitting a traceback when encountering pivot_root rules.

Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
---
 utils/apparmor/aa.py                | 49 +++++++++++++++++++++++
 utils/apparmor/rules.py             | 12 ++++++
 utils/test/test-pivot_root_parse.py | 36 +++++++++++++++++
 utils/test/test-regex_matches.py    | 79 +++++++++++++++++++++++++++++++++++++
 4 files changed, 176 insertions(+)
 create mode 100644 utils/test/test-pivot_root_parse.py

diff --git a/utils/apparmor/aa.py b/utils/apparmor/aa.py
index 8c1e374..a2971c3 100644
--- a/utils/apparmor/aa.py
+++ b/utils/apparmor/aa.py
@@ -2626,6 +2626,7 @@ RE_PROFILE_DBUS = re.compile('^\s*(audit\s+)?(allow\s+|deny\s+)?(dbus[^#]*\s*,)\
 RE_PROFILE_MOUNT = re.compile('^\s*(audit\s+)?(allow\s+|deny\s+)?((mount|remount|umount)[^#]*\s*,)\s*(#.*)?$')
 RE_PROFILE_SIGNAL = re.compile('^\s*(audit\s+)?(allow\s+|deny\s+)?((signal)[^#]*\s*,)\s*(#.*)?$')
 RE_PROFILE_PTRACE = re.compile('^\s*(audit\s+)?(allow\s+|deny\s+)?((ptrace)[^#]*\s*,)\s*(#.*)?$')
+RE_PROFILE_PIVOT_ROOT = re.compile('^\s*(audit\s+)?(allow\s+|deny\s+)?((pivot_root)[^#]*\s*,)\s*(#.*)?$')
 
 # match anything that's not " or #, or matching quotes with anything except quotes inside
 __re_no_or_quoted_hash = '([^#"]|"[^"]*")*'
@@ -2706,6 +2707,7 @@ def parse_profile_data(data, file, do_include):
             profile_data[profile][hat]['allow']['mount'] = list()
             profile_data[profile][hat]['allow']['signal'] = list()
             profile_data[profile][hat]['allow']['ptrace'] = list()
+            profile_data[profile][hat]['allow']['pivot_root'] = list()
             # Save the initial comment
             if initial_comment:
                 profile_data[profile][hat]['initial_comment'] = initial_comment
@@ -3110,6 +3112,28 @@ def parse_profile_data(data, file, do_include):
             ptrace_rules.append(ptrace_rule)
             profile_data[profile][hat][allow]['ptrace'] = ptrace_rules
 
+        elif RE_PROFILE_PIVOT_ROOT.search(line):
+            matches = RE_PROFILE_PIVOT_ROOT.search(line).groups()
+
+            if not profile:
+                raise AppArmorException(_('Syntax Error: Unexpected ptrace entry found in file: %s line: %s') % (file, lineno + 1))
+
+            audit = False
+            if matches[0]:
+                audit = True
+            allow = 'allow'
+            if matches[1] and matches[1].strip() == 'deny':
+                allow = 'deny'
+            pivot_root = matches[2].strip()
+
+            pivot_root_rule = parse_pivot_root_rule(pivot_root)
+            pivot_root_rule.audit = audit
+            pivot_root_rule.deny = (allow == 'deny')
+
+            pivot_root_rules = profile_data[profile][hat][allow].get('pivot_root', list())
+            pivot_root_rules.append(pivot_root_rule)
+            profile_data[profile][hat][allow]['pivot_root'] = pivot_root_rules
+
         elif RE_PROFILE_CHANGE_HAT.search(line):
             matches = RE_PROFILE_CHANGE_HAT.search(line).groups()
 
@@ -3216,6 +3240,10 @@ def parse_ptrace_rule(line):
     # XXX Do real parsing here
     return aarules.Raw_Ptrace_Rule(line)
 
+def parse_pivot_root_rule(line):
+    # XXX Do real parsing here
+    return aarules.Raw_Pivot_Root_Rule(line)
+
 def separate_vars(vs):
     """Returns a list of all the values for a variable"""
     data = []
@@ -3481,6 +3509,24 @@ def write_ptrace(prof_data, depth):
     data += write_ptrace_rules(prof_data, depth, 'allow')
     return data
 
+def write_pivot_root_rules(prof_data, depth, allow):
+    pre = '  ' * depth
+    data = []
+
+    # no pivot_root rules, so return
+    if not prof_data[allow].get('pivot_root', False):
+        return data
+
+    for pivot_root_rule in prof_data[allow]['pivot_root']:
+        data.append('%s%s' % (pre, pivot_root_rule.serialize()))
+    data.append('')
+    return data
+
+def write_pivot_root(prof_data, depth):
+    data = write_pivot_root_rules(prof_data, depth, 'deny')
+    data += write_pivot_root_rules(prof_data, depth, 'allow')
+    return data
+
 def write_link_rules(prof_data, depth, allow):
     pre = '  ' * depth
     data = []
@@ -3589,6 +3635,7 @@ def write_rules(prof_data, depth):
     data += write_mount(prof_data, depth)
     data += write_signal(prof_data, depth)
     data += write_ptrace(prof_data, depth)
+    data += write_pivot_root(prof_data, depth)
     data += write_links(prof_data, depth)
     data += write_paths(prof_data, depth)
     data += write_change_profile(prof_data, depth)
@@ -3740,6 +3787,7 @@ def serialize_profile_from_old_profile(profile_data, name, options):
                          'mount': write_mount,
                          'signal': write_signal,
                          'ptrace': write_ptrace,
+                         'pivot_root': write_pivot_root,
                          'link': write_links,
                          'path': write_paths,
                          'change_profile': write_change_profile,
@@ -3834,6 +3882,7 @@ def serialize_profile_from_old_profile(profile_data, name, options):
                     data += write_mount(write_prof_data[name], depth)
                     data += write_signal(write_prof_data[name], depth)
                     data += write_ptrace(write_prof_data[name], depth)
+                    data += write_pivot_root(write_prof_data[name], depth)
                     data += write_links(write_prof_data[name], depth)
                     data += write_paths(write_prof_data[name], depth)
                     data += write_change_profile(write_prof_data[name], depth)
diff --git a/utils/apparmor/rules.py b/utils/apparmor/rules.py
index 5b93e1e..36640f3 100644
--- a/utils/apparmor/rules.py
+++ b/utils/apparmor/rules.py
@@ -91,3 +91,15 @@ class Raw_Ptrace_Rule(object):
         return "%s%s%s" % ('audit ' if self.audit else '',
                            'deny '  if self.deny else '',
                            self.rule)
+
+class Raw_Pivot_Root_Rule(object):
+    audit = False
+    deny = False
+
+    def __init__(self, rule):
+        self.rule = rule
+
+    def serialize(self):
+        return "%s%s%s" % ('audit ' if self.audit else '',
+                           'deny '  if self.deny else '',
+                           self.rule)
diff --git a/utils/test/test-pivot_root_parse.py b/utils/test/test-pivot_root_parse.py
new file mode 100644
index 0000000..7b40f71
--- /dev/null
+++ b/utils/test/test-pivot_root_parse.py
@@ -0,0 +1,36 @@
+#! /usr/bin/env python
+# ------------------------------------------------------------------
+#
+#    Copyright (C) 2014 Canonical Ltd.
+#
+#    This program is free software; you can redistribute it and/or
+#    modify it under the terms of version 2 of the GNU General Public
+#    License published by the Free Software Foundation.
+#
+# ------------------------------------------------------------------
+
+import apparmor.aa as aa
+import unittest
+
+class AAParsePivotRootTest(unittest.TestCase):
+
+    def _test_parse_pivot_root_rule(self, rule):
+        pivot_root = aa.parse_pivot_root_rule(rule)
+        print(pivot_root.serialize())
+        self.assertEqual(rule, pivot_root.serialize(),
+                'pivot_root object returned "%s", expected "%s"' % (pivot_root.serialize(), rule))
+
+    def test_parse_plain_pivot_root_rule(self):
+        self._test_parse_pivot_root_rule('pivot_root,')
+
+    def test_parse_old_pivot_root_rule(self):
+        self._test_parse_pivot_root_rule('pivot_root /old,')
+
+    def test_parse_new_pivot_root_rule(self):
+        self._test_parse_pivot_root_rule('pivot_root /old /new,')
+
+    def test_parse_child_pivot_root_rule(self):
+        self._test_parse_pivot_root_rule('pivot_root /old /new -> /usr/bin/child,')
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/utils/test/test-regex_matches.py b/utils/test/test-regex_matches.py
index 3118c35..6d596bd 100644
--- a/utils/test/test-regex_matches.py
+++ b/utils/test/test-regex_matches.py
@@ -53,6 +53,11 @@ regex_has_comma_testcases = [
     ('ptrace (tracedby, readby)%s', 'embedded parens ptrace 01'),
     ('ptrace (trace) peer=/usr/bin/foo%s', 'embedded parens ptrace 02'),
 
+    ('pivot_root%s', 'bare pivot_root'),
+    ('pivot_root /old%s', 'pivot_root with old'),
+    ('pivot_root /old new%s', 'pivot_root with new'),
+    ('pivot_root /old /new -> child%s', 'pivot_root with child'),
+
     # the following fail due to inadequacies in the regex
     # ('dbus (r, w, %s', 'incomplete dbus action'),
     # ('member="{Hello,AddMatch,RemoveMatch, %s', 'incomplete {} regex'),  # also invalid policy
@@ -113,6 +118,8 @@ regex_split_comment_testcases = [
     ('signal receive set=(usr1 usr2) peer=foo,', False),
     ('ptrace, # comment', ('ptrace, ', '# comment')),
     ('ptrace (trace read) peer=/usr/bin/foo,', False),
+    ('pivot_root, # comment', ('pivot_root, ', '# comment')),
+    ('pivot_root /old /new -> child,', False),
 ]
 
 def setup_split_comment_testcases():
@@ -443,6 +450,77 @@ class AARegexPtrace(unittest.TestCase):
         self.assertEqual(parsed, rule, 'Expected ptrace rule "%s", got "%s"'
                          % (rule, parsed))
 
+class AARegexPivotRoot(unittest.TestCase):
+    '''Tests for RE_PROFILE_PIVOT_ROOT'''
+
+    def test_bare_pivot_root_01(self):
+        '''test '   pivot_root,' '''
+
+        rule = 'pivot_root,'
+        line = '   %s' % rule
+        result = aa.RE_PROFILE_PIVOT_ROOT.search(line)
+        self.assertTrue(result, 'Couldn\'t find pivot_root rule in "%s"' % line)
+        parsed = result.groups()[2].strip()
+        self.assertEqual(parsed, rule, 'Expected pivot_root rule "%s", got "%s"'
+                         % (rule, parsed))
+
+    def test_bare_pivot_root_02(self):
+        '''test '   audit pivot_root,' '''
+
+        rule = 'pivot_root,'
+        line = '   audit %s' % rule
+        result = aa.RE_PROFILE_PIVOT_ROOT.search(line)
+        self.assertTrue(result, 'Couldn\'t find pivot_root rule in "%s"' % line)
+        self.assertTrue(result.groups()[0], 'Couldn\'t find audit modifier in "%s"' % line)
+        parsed = result.groups()[2].strip()
+        self.assertEqual(parsed, rule, 'Expected pivot_root rule "%s", got "%s"'
+                         % (rule, parsed))
+
+    def test_old_pivot_root_01(self):
+        '''test '   pivot_root /old,' '''
+
+        rule = 'pivot_root /old,'
+        line = '   %s' % rule
+        result = aa.RE_PROFILE_PIVOT_ROOT.search(line)
+        self.assertTrue(result, 'Couldn\'t find pivot_root rule in "%s"' % line)
+        parsed = result.groups()[2].strip()
+        self.assertEqual(parsed, rule, 'Expected pivot_root rule "%s", got "%s"'
+                         % (rule, parsed))
+
+    def test_new_pivot_root_01(self):
+        '''test '   pivot_root /old /new,' '''
+
+        rule = 'pivot_root /old /new,'
+        line = '   %s' % rule
+        result = aa.RE_PROFILE_PIVOT_ROOT.search(line)
+        self.assertTrue(result, 'Couldn\'t find pivot_root rule in "%s"' % line)
+        parsed = result.groups()[2].strip()
+        self.assertEqual(parsed, rule, 'Expected pivot_root rule "%s", got "%s"'
+                         % (rule, parsed))
+
+    def test_child_pivot_root_01(self):
+        '''test '   pivot_root /old /new -> child,' '''
+
+        rule = 'pivot_root /old /new -> child,'
+        line = '   %s' % rule
+        result = aa.RE_PROFILE_PIVOT_ROOT.search(line)
+        self.assertTrue(result, 'Couldn\'t find pivot_root rule in "%s"' % line)
+        parsed = result.groups()[2].strip()
+        self.assertEqual(parsed, rule, 'Expected pivot_root rule "%s", got "%s"'
+                         % (rule, parsed))
+
+    def test_child_pivot_root_02(self):
+        '''test '   audit pivot_root /old /new -> child,' '''
+
+        rule = 'pivot_root /old /new -> child,'
+        line = '   audit %s' % rule
+        result = aa.RE_PROFILE_PIVOT_ROOT.search(line)
+        self.assertTrue(result, 'Couldn\'t find pivot_root rule in "%s"' % line)
+        self.assertTrue(result.groups()[0], 'Couldn\'t find audit modifier in "%s"' % line)
+        parsed = result.groups()[2].strip()
+        self.assertEqual(parsed, rule, 'Expected pivot_root rule "%s", got "%s"'
+                         % (rule, parsed))
+
 if __name__ == '__main__':
     verbosity = 2
 
@@ -457,6 +535,7 @@ if __name__ == '__main__':
     test_suite.addTest(unittest.TestLoader().loadTestsFromTestCase(AARegexFile))
     test_suite.addTest(unittest.TestLoader().loadTestsFromTestCase(AARegexSignal))
     test_suite.addTest(unittest.TestLoader().loadTestsFromTestCase(AARegexPtrace))
+    test_suite.addTest(unittest.TestLoader().loadTestsFromTestCase(AARegexPivotRoot))
     result = unittest.TextTestRunner(verbosity=verbosity).run(test_suite)
     if not result.wasSuccessful():
         exit(1)
-- 
1.9.1




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