On 12/21/20 7:22 AM, Richard Haines wrote:
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.
Resolve this by using selinux_binary_policy_path(3) to determine the
current configured policy name and its location.
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 this by checking if DESTDIR has been set.
Remove the '@touch $(tmpdir)/load' line as the file is never referenced.
Signed-off-by: Richard Haines <richard_c_haines@xxxxxxxxxxxxxx>
---
V2 Changes: Use $(error .. instead of NO_LOAD logic. Use python script to
find selinux path not sestatus. Reword error messages.
V3 Change: Use the selinux_binary_policy_path() python script and reword
error messages.
Makefile | 1 +
Rules.monolithic | 15 ++++++++++++++-
support/selinux_binary_policy_path.py | 12 ++++++++++++
3 files changed, 27 insertions(+), 1 deletion(-)
create mode 100644 support/selinux_binary_policy_path.py
diff --git a/Makefile b/Makefile
index 6ba215f1..1b0a4826 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
+binary_policy_path := $(PYTHON) $(support)/selinux_binary_policy_path.py
fcsort := $(PYTHON) $(support)/fc_sort.py
setbools := $(AWK) -f $(support)/set_bools_tuns.awk
get_type_attr_decl := $(SED) -r -f $(support)/get_type_attr_decl.sed
diff --git a/Rules.monolithic b/Rules.monolithic
index a8ae98d1..7dbc2e1c 100644
--- a/Rules.monolithic
+++ b/Rules.monolithic
@@ -13,6 +13,12 @@ ifeq "$(kv)" ""
kv := $(pv)
endif
+# load_policy(8) loads policy from /etc/selinux/<SELINUXTYPE>/policy/policy.$(pv)
+# It does this by reading the /etc/selinux/config file SELINUXTYPE entry to
+# form the full path. $(polbinpath) will contain this evaluated path for use as
+# a validation check.
+polbinpath := $(shell $(binary_policy_path))
+
policy_conf = $(builddir)policy.conf
fc = $(builddir)file_contexts
polver = $(builddir)policy.$(pv)
@@ -91,9 +97,16 @@ endif
# Load the binary policy
#
reload $(tmpdir)/load: $(loadpath) $(fcpath) $(appfiles)
+ifneq ($(DESTDIR),)
+ $(error Cannot load policy as '$$DESTDIR' is set to $(DESTDIR), \
+ creating an invalid policy load path)
+endif
+ifneq ($(polbinpath).$(pv),$(loadpath))
+ $(error Cannot load policy as invalid policy path: $(polbinpath).$(pv) - \
+ Check $(topdir)/config file entry is: "SELINUXTYPE=$(NAME)")
+endif
@echo "Loading $(NAME) $(loadpath)"
$(verbose) $(LOADPOLICY) -q $(loadpath)
- @touch $(tmpdir)/load
########################################
#
diff --git a/support/selinux_binary_policy_path.py b/support/selinux_binary_policy_path.py
new file mode 100644
index 00000000..a30eb9b6
--- /dev/null
+++ b/support/selinux_binary_policy_path.py
@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+
+try:
+ import warnings
+ with warnings.catch_warnings():
+ warnings.filterwarnings("ignore", category=PendingDeprecationWarning)
+ import selinux
+
+ if selinux.is_selinux_enabled():
+ print(selinux.selinux_binary_policy_path())
+except ImportError:
+ exit(0)
Merged, sorry for the slow response.
--
Chris PeBenito
