[apparmor] [patch] merge script handling into get_interpreter_and_abstraction()
Kshitij Gupta
kgupta8592 at gmail.com
Sun Oct 18 19:42:03 UTC 2015
Hello,
On Sun, Oct 18, 2015 at 8:17 PM, Christian Boltz <apparmor at cboltz.de> wrote:
> Hello,
>
> both create_new_profile() and handle_children() check if the given exec
> target is a script and add permissions for the interpreter and a
> matching abstraction.
>
> This patch merges that into the get_interpreter_and_abstraction()
> function and changes create_new_profile() and handle_children() to use
> this function.
>
> A nice side effect is that handle_children() now knows more abstractions
> (its original list was incomplete).
> The behaviour of create_new_profile() doesn't change.
>
> Also add tests for get_interpreter_and_abstraction() to make sure it
> does what we expect.
>
>
> [ 94-merge-script-handling-into-get_interpreter_and_abstraction.diff ]
>
Ahh, a patch a just reviewed was based on the above. I was wondering why I
couldn't find it on my local bzr.
>
> --- utils/apparmor/aa.py 2015-10-18 16:31:12.192164267 +0200
> +++ utils/apparmor/aa.py 2015-10-18 16:37:09.794351825 +0200
> @@ -397,6 +397,42 @@
> profile['allow']['path'][library]['mode'] =
> profile['allow']['path'][library].get('mode', set()) | str_to_mode('mr')
> profile['allow']['path'][library]['audit'] |=
> profile['allow']['path'][library].get('audit', set())
>
> +def get_interpreter_and_abstraction(exec_target):
> + '''Check if exec_target is a script.
> + If a hashbang is found, check if we have an abstraction for it.
> +
> + Returns (interpreter_path, abstraction)
> + - interpreter_path is none if exec_target is not a script or
> doesn't have a hashbang line
> + - abstraction is None if no matching abstraction exists'''
> +
> + if not os.path.exists(exec_target):
> + aaui.UI_Important(_('Execute target %s does not exist!') %
> exec_target)
> + return None, None
>
Add a new line here.
> + if not os.path.isfile(exec_target):
> + aaui.UI_Important(_('Execute target %s is not a file!') %
> exec_target)
> + return None, None
> +
> + hashbang = head(exec_target)
> + if not hashbang.startswith('#!'):
> + return None, None
> +
> + interpreter = hashbang[2:].strip()
> + interpreter_path = get_full_path(interpreter)
>
Please look for some suggestions in my reply for patch 95 (*wow*, close to
100 patches!)
+ interpreter = re.sub('^(/usr)?/bin/', '', interpreter_path)
>
Consider moving the regex outside and compiling it beforehand.
+
> + if interpreter in ['bash', 'dash', 'sh']:
> + abstraction = 'abstractions/bash'
> + elif interpreter == 'perl':
> + abstraction = 'abstractions/perl'
> + elif re.search('^python([23]|[23]\.[0-9]+)?$', interpreter):
> + abstraction = 'abstractions/python'
> + elif interpreter == 'ruby':
> + abstraction = 'abstractions/ruby'
> + else:
> + abstraction = None
> +
> + return interpreter_path, abstraction
> +
> def get_inactive_profile(local_profile):
> if extras.get(local_profile, False):
> return {local_profile: extras[local_profile]}
> @@ -439,12 +475,9 @@
> local_profile[localfile]['include']['abstractions/base'] = 1
>
> if os.path.exists(localfile) and os.path.isfile(localfile):
> - hashbang = head(localfile)
> - if hashbang.startswith('#!'):
> - interpreter_path =
> get_full_path(hashbang.lstrip('#!').strip())
> -
> - interpreter = re.sub('^(/usr)?/bin/', '', interpreter_path)
> + interpreter_path, abstraction =
> get_interpreter_and_abstraction(localfile)
>
> + if interpreter_path:
> local_profile[localfile]['allow']['path'][localfile]['mode']
> = local_profile[localfile]['allow']['path'][localfile].get('mode',
> str_to_mode('r')) | str_to_mode('r')
>
> local_profile[localfile]['allow']['path'][localfile]['audit']
> = local_profile[localfile]['allow']['path'][localfile].get('audit', set())
> @@ -453,14 +486,9 @@
>
>
> local_profile[localfile]['allow']['path'][interpreter_path]['audit'] =
> local_profile[localfile]['allow']['path'][interpreter_path].get('audit',
> set())
>
> - if interpreter == 'perl':
> - local_profile[localfile]['include']['abstractions/perl']
> = True
> - elif re.search('^python([23]|[23]\.[0-9]+)?$', interpreter):
> -
> local_profile[localfile]['include']['abstractions/python'] = True
> - elif interpreter == 'ruby':
> - local_profile[localfile]['include']['abstractions/ruby']
> = True
> - elif interpreter in ['bash', 'dash', 'sh']:
> - local_profile[localfile]['include']['abstractions/bash']
> = True
> + if abstraction:
> + local_profile[localfile]['include'][abstraction] = True
> +
> handle_binfmt(local_profile[localfile], interpreter_path)
> else:
>
> @@ -1407,24 +1435,15 @@
> changed[profile] = True
>
> if exec_mode & str_to_mode('i'):
> - #if 'perl' in exec_target:
> - #
> aa[profile][hat]['include']['abstractions/perl'] = True
> - #elif '/bin/bash' in exec_target or
> '/bin/sh' in exec_target:
> - #
> aa[profile][hat]['include']['abstractions/bash'] = True
> - hashbang = head(exec_target)
> - if hashbang.startswith('#!'):
> - interpreter = hashbang[2:].strip()
> - interpreter_path =
> get_full_path(interpreter)
> - interpreter = re.sub('^(/usr)?/bin/',
> '', interpreter_path)
> + interpreter_path, abstraction =
> get_interpreter_and_abstraction(exec_target)
>
> + if interpreter_path:
>
> aa[profile][hat]['allow']['path'][interpreter_path]['mode'] =
> aa[profile][hat]['allow']['path'][interpreter_path].get('mode',
> str_to_mode('ix')) | str_to_mode('ix')
>
>
> aa[profile][hat]['allow']['path'][interpreter_path]['audit'] =
> aa[profile][hat]['allow']['path'][interpreter_path].get('audit', set())
>
> - if interpreter == 'perl':
> -
> aa[profile][hat]['include']['abstractions/perl'] = True
> - elif interpreter in ['bash', 'dash',
> 'sh']:
> -
> aa[profile][hat]['include']['abstractions/bash'] = True
> + if abstraction:
> +
> aa[profile][hat]['include'][abstraction] = True
>
> # Update tracking info based on kind of change
>
> --- utils/test/test-aa.py 2015-10-18 16:19:32.501921777 +0200
> +++ utils/test/test-aa.py 2015-10-18 16:18:51.129325349 +0200
> @@ -13,7 +13,9 @@
> from common_test import AATest, setup_all_loops
> from common_test import read_file, write_file
>
> -from apparmor.aa import (check_for_apparmor, create_new_profile,
> +import os
> +
> +from apparmor.aa import (check_for_apparmor,
> get_interpreter_and_abstraction, create_new_profile,
> get_profile_flags, set_profile_flags, is_skippable_file,
> is_skippable_dir,
> parse_profile_start, parse_profile_data, separate_vars,
> store_list_var, write_header, serialize_parse_profile_start)
> from apparmor.common import AppArmorException, AppArmorBug
> @@ -97,6 +99,47 @@
> else:
> self.assertEqual(profile[program][program]['include'].keys(),
> {'abstractions/base'})
>
> +class AaTest_get_interpreter_and_abstraction(AATest):
> + tests = [
> + ('#!/bin/bash', ('/bin/bash',
> 'abstractions/bash')),
> + ('#!/bin/dash', ('/bin/dash',
> 'abstractions/bash')),
> + ('#!/bin/sh', ('/bin/sh',
> 'abstractions/bash')),
> + ('#! /bin/sh ', ('/bin/sh',
> 'abstractions/bash')),
> + ('#!/usr/bin/perl', ('/usr/bin/perl',
> 'abstractions/perl')),
> + ('#!/usr/bin/python', ('/usr/bin/python',
> 'abstractions/python')),
> + ('#!/usr/bin/python2', ('/usr/bin/python2',
> 'abstractions/python')),
> + ('#!/usr/bin/python2.7', ('/usr/bin/python2.7',
> 'abstractions/python')),
> + ('#!/usr/bin/python3', ('/usr/bin/python3',
> 'abstractions/python')),
> + ('#!/usr/bin/python4', ('/usr/bin/python4', None)), #
> python abstraction is only applied to py2 and py3
> + ('#!/usr/bin/ruby', ('/usr/bin/ruby',
> 'abstractions/ruby')),
> + ('#!/usr/bin/foobarbaz', ('/usr/bin/foobarbaz', None)), # we
> don't have an abstraction for "foobarbaz"
> + ('foo', (None, None)), # no
> hashbang - not a script
> + ]
> +
> + def _run_test(self, params, expected):
> + exp_interpreter_path, exp_abstraction = expected
> +
> + program = self.writeTmpfile('program', "%s\nfoo\nbar" % params)
> + interpreter_path, abstraction =
> get_interpreter_and_abstraction(program)
> +
> + # damn symlinks!
>
lol
+ if exp_interpreter_path and os.path.islink(exp_interpreter_path):
> + dirname = os.path.dirname(exp_interpreter_path)
> + exp_interpreter_path = os.readlink(exp_interpreter_path)
> + if not exp_interpreter_path.startswith('/'):
> + exp_interpreter_path = os.path.join(dirname,
> exp_interpreter_path)
> +
> + self.assertEqual(interpreter_path, exp_interpreter_path)
> + self.assertEqual(abstraction, exp_abstraction)
> +
> + def test_special_file(self):
> + self.assertEqual((None, None),
> get_interpreter_and_abstraction('/dev/null'))
> +
> + def test_file_not_found(self):
> + self.createTmpdir()
> + self.assertEqual((None, None),
> get_interpreter_and_abstraction('%s/file-not-found' % self.tmpdir))
> +
> +
> class AaTest_get_profile_flags(AaTestWithTempdir):
> def _test_get_flags(self, profile_header, expected_flags):
> file = write_file(self.tmpdir, 'profile', '%s {\n}\n' %
> profile_header)
>
> Thanks for the patch.
Acked-by: Kshitij Gupta <kgupta8592 at gmail.com>.
> Regards,
>
> Christian Boltz
> --
> Disclaimer: In case you are either 1) a complete idiot; or 2) a lawyer;
> or 3) both, please be aware that [...] [from fixubuntu.com]
>
>
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--
Regards,
Kshitij Gupta
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