From: Richard Haines <richard_c_haines@btinternet.com>
To: selinux-refpolicy@vger.kernel.org
Cc: Richard Haines <richard_c_haines@btinternet.com>
Subject: [PATCH V2] Ensure correct monolithic binary policy is loaded
Date: Fri, 18 Dec 2020 15:03:07 +0000 [thread overview]
Message-ID: <20201218150307.8826-1-richard_c_haines@btinternet.com> (raw)
When building a monolithic policy with 'make load', the
selinux_config(5) file 'SELINUXTYPE' entry determines what policy
is loaded as load_policy(8) does not take a path value (it always loads
the active system policy as defined by /etc/selinux/config).
Currently it is possible to load the wrong binary policy, for example if
the Reference Policy source is located at:
/etc/selinux/refpolicy
and the /etc/selinux/config file has the following entry:
SELINUXTYPE=targeted
Then the /etc/selinux/targeted/policy/policy.<ver> is loaded when
'make load' is executed.
Another example is that if the Reference Policy source is located at:
/tmp/custom-rootfs/etc/selinux/refpolicy
and the /etc/selinux/config file has the following entry:
SELINUXTYPE=refpolicy
Then the /etc/selinux/refpolicy/policy/policy.<ver> is loaded when
'make DESTDIR=/tmp/custom-rootfs load' is executed (not the
/tmp/custom-rootfs/etc/selinux/refpolicy/policy/policy.<ver> that the
developer thought would be loaded).
Resolve these issues by using selinux_path(3) to resolve the policy root,
then checking the selinux_config(5) file for the appropriate SELINUXTYPE
entry.
Remove the '@touch $(tmpdir)/load' line as the file is never referenced.
Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
---
V2 Changes: Use $(error .. instead of NO_LOAD logic. Use python script to
find selinux path not sestatus. Reword error messages.
Makefile | 1 +
Rules.monolithic | 15 ++++++++++++++-
support/selinux_path.py | 13 +++++++++++++
3 files changed, 28 insertions(+), 1 deletion(-)
create mode 100644 support/selinux_path.py
diff --git a/Makefile b/Makefile
index 6ba215f1..e49d43d0 100644
--- a/Makefile
+++ b/Makefile
@@ -97,6 +97,7 @@ genxml := $(PYTHON) $(support)/segenxml.py
gendoc := $(PYTHON) $(support)/sedoctool.py
genperm := $(PYTHON) $(support)/genclassperms.py
policyvers := $(PYTHON) $(support)/policyvers.py
+selinux_path := $(PYTHON) $(support)/selinux_path.py
fcsort := $(PYTHON) $(support)/fc_sort.py
setbools := $(AWK) -f $(support)/set_bools_tuns.awk
get_type_attr_decl := $(SED) -r -f $(support)/get_type_attr_decl.sed
diff --git a/Rules.monolithic b/Rules.monolithic
index a8ae98d1..cd065362 100644
--- a/Rules.monolithic
+++ b/Rules.monolithic
@@ -42,6 +42,12 @@ vpath %.te $(all_layers)
vpath %.if $(all_layers)
vpath %.fc $(all_layers)
+# load_policy(8) loads policy from <SELINUX_PATH>/<SELINUXTYPE>/policy/policy.<ver>
+# It does this by reading the <SELINUX_PATH>/config file and using the
+# SELINUX_PATH/SELINUXTYPE entries to form the initial path.
+SELINUX_PATH := $(shell $(selinux_path))
+SELINUXTYPE := $(strip $(shell $(AWK) -F= '/^SELINUXTYPE/{ print $$2 }' $(SELINUX_PATH)/config))
+
########################################
#
# default action: build policy locally
@@ -91,9 +97,16 @@ endif
# Load the binary policy
#
reload $(tmpdir)/load: $(loadpath) $(fcpath) $(appfiles)
+ifneq ($(SELINUXTYPE),$(NAME))
+ $(error Cannot load policy as $(SELINUX_PATH)/config file contains SELINUXTYPE=$(SELINUXTYPE) - \
+ Edit $(SELINUX_PATH)/config and set "SELINUXTYPE=$(NAME)")
+endif
+ifneq ($(topdir),$(SELINUX_PATH))
+ $(error Cannot load policy as policy root MUST be $(SELINUX_PATH)/$(NAME) - \
+ Current policy root is: $(topdir)/$(NAME))
+endif
@echo "Loading $(NAME) $(loadpath)"
$(verbose) $(LOADPOLICY) -q $(loadpath)
- @touch $(tmpdir)/load
########################################
#
diff --git a/support/selinux_path.py b/support/selinux_path.py
new file mode 100644
index 00000000..b663ff09
--- /dev/null
+++ b/support/selinux_path.py
@@ -0,0 +1,13 @@
+#!/usr/bin/env python3
+
+try:
+ import warnings
+ with warnings.catch_warnings():
+ warnings.filterwarnings("ignore", category=PendingDeprecationWarning)
+ import selinux
+
+ if selinux.is_selinux_enabled():
+ # Strip the trailing '/'
+ print(selinux.selinux_path()[:-1])
+except ImportError:
+ exit(0)
--
2.29.2
next reply other threads:[~2020-12-18 15:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-18 15:03 Richard Haines [this message]
2020-12-19 20:49 ` [PATCH V2] Ensure correct monolithic binary policy is loaded Chris PeBenito
2020-12-20 12:31 ` Richard Haines
2020-12-20 14:54 ` Chris PeBenito
2020-12-20 15:01 ` Chris PeBenito
2020-12-20 16:40 ` Richard Haines
2020-12-20 17:46 ` Chris PeBenito
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201218150307.8826-1-richard_c_haines@btinternet.com \
--to=richard_c_haines@btinternet.com \
--cc=selinux-refpolicy@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).