Bug #189417 - Comment on how the whitelist and BASH_ENV are used to

prevent environment leakage.

svn path=/main/trunk/; revision=8867

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index dbbe97e3ae3201faa948d52f53a8d882c3a812c1..711355e01b1dce4578bf096a2134f1b96cedddf4 100644 (file)
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -860,9 +860,14 @@ class config(object):
 
        _environ_whitelist = []
 
-       # Preserve backupenv values that are initialized in the config
-       # constructor. Also, preserve XARGS since it is set by the
-       # portage.data module.
+       # Whitelisted variables are always allowed to enter the ebuild
+       # environment. Generally, this only includes special portage
+       # variables. Ebuilds can unset variables that are not whitelisted
+       # and rely on them remaining unset for future phases, without them
+       # leaking back in from various locations (bug #189417). It's very
+       # important to set our special BASH_ENV variable in the ebuild
+       # environment in order to prevent sandbox from sourcing /etc/profile
+       # in it's bashrc (causing major leakage).
        _environ_whitelist += [
                "BASH_ENV", "BUILD_PREFIX", "D",
                "DISTDIR", "DOC_SYMLINKS_DIR", "EBUILD_EXIT_STATUS_FILE",