From 42523faa48db8e5acbb6f6a1bbadd8a115ed8650 Mon Sep 17 00:00:00 2001 From: Paul Eggleton Date: Fri, 17 Apr 2015 15:26:59 +0100 Subject: [PATCH] bitbake: lib/bb/utils: add safeguard against recursively deleting things we shouldn't Add some very basic safeguard against recursively deleting paths such as / and /home in the event of bugs or user mistakes. Addresses [YOCTO #7620]. (Bitbake master rev: 56cddeb9e1e4d249f84ccd6ef65db245636e38ea) (Bitbake rev: fbf1c39641f78d553961974a2bb96256eb9496e7) Signed-off-by: Paul Eggleton Signed-off-by: Richard Purdie Signed-off-by: Mauro Carvalho Chehab --- bitbake/lib/bb/tests/utils.py | 50 +++++++++++++++++++++++++++++++++++++++++++ bitbake/lib/bb/utils.py | 21 ++++++++++++++++++ 2 files changed, 71 insertions(+) diff --git a/bitbake/lib/bb/tests/utils.py b/bitbake/lib/bb/tests/utils.py index 7c50b1d..677b387 100644 --- a/bitbake/lib/bb/tests/utils.py +++ b/bitbake/lib/bb/tests/utils.py @@ -21,6 +21,7 @@ import unittest import bb +import os class VerCmpString(unittest.TestCase): @@ -51,3 +52,52 @@ class VerCmpString(unittest.TestCase): result = bb.utils.explode_dep_versions2("foo ( =1.10 )") self.assertEqual(result, correctresult) + def test_vercmp_string_op(self): + compareops = [('1', '1', '=', True), + ('1', '1', '==', True), + ('1', '1', '!=', False), + ('1', '1', '>', False), + ('1', '1', '<', False), + ('1', '1', '>=', True), + ('1', '1', '<=', True), + ('1', '0', '=', False), + ('1', '0', '==', False), + ('1', '0', '!=', True), + ('1', '0', '>', True), + ('1', '0', '<', False), + ('1', '0', '>>', True), + ('1', '0', '<<', False), + ('1', '0', '>=', True), + ('1', '0', '<=', False), + ('0', '1', '=', False), + ('0', '1', '==', False), + ('0', '1', '!=', True), + ('0', '1', '>', False), + ('0', '1', '<', True), + ('0', '1', '>>', False), + ('0', '1', '<<', True), + ('0', '1', '>=', False), + ('0', '1', '<=', True)] + + for arg1, arg2, op, correctresult in compareops: + result = bb.utils.vercmp_string_op(arg1, arg2, op) + self.assertEqual(result, correctresult, 'vercmp_string_op("%s", "%s", "%s") != %s' % (arg1, arg2, op, correctresult)) + + # Check that clearly invalid operator raises an exception + self.assertRaises(bb.utils.VersionStringException, bb.utils.vercmp_string_op, '0', '0', '$') + + +class Path(unittest.TestCase): + def test_unsafe_delete_path(self): + checkitems = [('/', True), + ('//', True), + ('///', True), + (os.getcwd().count(os.sep) * ('..' + os.sep), True), + (os.environ.get('HOME', '/home/test'), True), + ('/home/someone', True), + ('/home/other/', True), + ('/home/other/subdir', False), + ('', False)] + for arg1, correctresult in checkitems: + result = bb.utils._check_unsafe_delete_path(arg1) + self.assertEqual(result, correctresult, '_check_unsafe_delete_path("%s") != %s' % (arg1, correctresult)) diff --git a/bitbake/lib/bb/utils.py b/bitbake/lib/bb/utils.py index 670e592..2562db8 100644 --- a/bitbake/lib/bb/utils.py +++ b/bitbake/lib/bb/utils.py @@ -575,11 +575,30 @@ def build_environment(d): if export: os.environ[var] = d.getVar(var, True) or "" +def _check_unsafe_delete_path(path): + """ + Basic safeguard against recursively deleting something we shouldn't. If it returns True, + the caller should raise an exception with an appropriate message. + NOTE: This is NOT meant to be a security mechanism - just a guard against silly mistakes + with potentially disastrous results. + """ + extra = '' + # HOME might not be /home/something, so in case we can get it, check against it + homedir = os.environ.get('HOME', '') + if homedir: + extra = '|%s' % homedir + if re.match('(/|//|/home|/home/[^/]*%s)$' % extra, os.path.abspath(path)): + return True + return False + def remove(path, recurse=False): """Equivalent to rm -f or rm -rf""" if not path: return if recurse: + for name in glob.glob(path): + if _check_unsafe_delete_path(path): + raise Exception('bb.utils.remove: called with dangerous path "%s" and recurse=True, refusing to delete!' % path) # shutil.rmtree(name) would be ideal but its too slow subprocess.call(['rm', '-rf'] + glob.glob(path)) return @@ -593,6 +612,8 @@ def remove(path, recurse=False): def prunedir(topdir): # Delete everything reachable from the directory named in 'topdir'. # CAUTION: This is dangerous! + if _check_unsafe_delete_path(topdir): + raise Exception('bb.utils.prunedir: called with dangerous path "%s", refusing to delete!' % topdir) for root, dirs, files in os.walk(topdir, topdown = False): for name in files: os.remove(os.path.join(root, name)) -- 2.7.4