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/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/refpolicy/policy/policy.<ver> that the developer
thought would be loaded).
Resolve these issues by using sestatus(8) 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 <[email protected]>
---
Makefile | 1 +
Rules.monolithic | 31 ++++++++++++++++++++++++++++---
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
index 6ba215f1..88a5e78f 100644
--- a/Makefile
+++ b/Makefile
@@ -64,6 +64,7 @@ SEMOD_EXP ?= $(tc_usrbindir)/semodule_expand
LOADPOLICY ?= $(tc_usrsbindir)/load_policy
SEPOLGEN_IFGEN ?= $(tc_usrbindir)/sepolgen-ifgen
SETFILES ?= $(tc_sbindir)/setfiles
+SESTATUS ?= $(tc_sbindir)/sestatus
XMLLINT ?= $(BINDIR)/xmllint
SECHECK ?= $(BINDIR)/sechecker
diff --git a/Rules.monolithic b/Rules.monolithic
index a8ae98d1..01e445ca 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 <SELINUXDIR>/<SELINUXTYPE>/policy/policy.<ver>
+# Therefore need to determine if policy to load is in the right place,
+SELINUXDIR ?= $(strip $(shell $(SESTATUS) | $(AWK) '/^SELinux root directory:/{ print $$4 }'))
+# and that <SELINUXDIR>/config contains the correct SELINUXTYPE entry.
+SELINUXTYPE ?= $(strip $(shell $(AWK) -F= '/^SELINUXTYPE/{ print $$2 }' $(SELINUXDIR)/config))
+
########################################
#
# default action: build policy locally
@@ -91,9 +97,28 @@ endif
# Load the binary policy
#
reload $(tmpdir)/load: $(loadpath) $(fcpath) $(appfiles)
- @echo "Loading $(NAME) $(loadpath)"
- $(verbose) $(LOADPOLICY) -q $(loadpath)
- @touch $(tmpdir)/load
+ifneq ($(SELINUXTYPE),$(NAME))
+ $(eval NO_LOAD := $(shell echo 1))
+ @echo
+ @echo "Warning: Cannot load policy as $(SELINUXDIR)/config file contains:"
+ @echo -e "\tSELINUXTYPE=$(SELINUXTYPE)"
+ @echo "Edit $(SELINUXDIR)/config and set \"SELINUXTYPE=$(NAME)\"."
+ @echo
+endif
+
+ifneq ($(topdir),$(SELINUXDIR))
+ $(eval NO_LOAD := $(shell echo 1))
+ @echo
+ @echo "Warning: Cannot load policy as policy root MUST be $(SELINUXDIR)/$(NAME)"
+ @echo
+endif
+
+ @if test -z $(NO_LOAD); then \
+ echo "Loading $(NAME) $(loadpath)" ;\
+ $(verbose) $(LOADPOLICY) -q $(loadpath) ;\
+ else \
+ echo "Resolve binary policy configuration" ;\
+ fi
########################################
#
--
2.29.2
On 12/17/20 11:42 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.
>
> Another example is that if the Reference Policy source is located at:
> /tmp/custom-rootfs/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/refpolicy/policy/policy.<ver> that the developer
> thought would be loaded).
>
> Resolve these issues by using sestatus(8) 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 <[email protected]>
> ---
> Makefile | 1 +
> Rules.monolithic | 31 ++++++++++++++++++++++++++++---
> 2 files changed, 29 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 6ba215f1..88a5e78f 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -64,6 +64,7 @@ SEMOD_EXP ?= $(tc_usrbindir)/semodule_expand
> LOADPOLICY ?= $(tc_usrsbindir)/load_policy
> SEPOLGEN_IFGEN ?= $(tc_usrbindir)/sepolgen-ifgen
> SETFILES ?= $(tc_sbindir)/setfiles
> +SESTATUS ?= $(tc_sbindir)/sestatus
> XMLLINT ?= $(BINDIR)/xmllint
> SECHECK ?= $(BINDIR)/sechecker
>
> diff --git a/Rules.monolithic b/Rules.monolithic
> index a8ae98d1..01e445ca 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 <SELINUXDIR>/<SELINUXTYPE>/policy/policy.<ver>
> +# Therefore need to determine if policy to load is in the right place,
> +SELINUXDIR ?= $(strip $(shell $(SESTATUS) | $(AWK) '/^SELinux root directory:/{ print $$4 }'))
> +# and that <SELINUXDIR>/config contains the correct SELINUXTYPE entry.
> +SELINUXTYPE ?= $(strip $(shell $(AWK) -F= '/^SELINUXTYPE/{ print $$2 }' $(SELINUXDIR)/config))
Rather than parsing sestatus output, I'd prefer do a tiny Python script that
gets the policy path, e.g.:
python -c 'import selinux; print(selinux.selinux_binary_policy_path())'
See support/policyvers.py too.
> ########################################
> #
> # default action: build policy locally
> @@ -91,9 +97,28 @@ endif
> # Load the binary policy
> #
> reload $(tmpdir)/load: $(loadpath) $(fcpath) $(appfiles)
> - @echo "Loading $(NAME) $(loadpath)"
> - $(verbose) $(LOADPOLICY) -q $(loadpath)
> - @touch $(tmpdir)/load
> +ifneq ($(SELINUXTYPE),$(NAME))
> + $(eval NO_LOAD := $(shell echo 1))
I think it would be cleaner to use the $(error msg_text) function to terminate
make rather than the NO_LOAD logic.
See https://www.gnu.org/software/make/manual/make.html#Make-Control-Functions
> + @echo
> + @echo "Warning: Cannot load policy as $(SELINUXDIR)/config file contains:"
> + @echo -e "\tSELINUXTYPE=$(SELINUXTYPE)"
> + @echo "Edit $(SELINUXDIR)/config and set \"SELINUXTYPE=$(NAME)\"."
> + @echo
> +endif
> +
> +ifneq ($(topdir),$(SELINUXDIR))
> + $(eval NO_LOAD := $(shell echo 1))
> + @echo
> + @echo "Warning: Cannot load policy as policy root MUST be $(SELINUXDIR)/$(NAME)"
> + @echo
> +endif
> +
> + @if test -z $(NO_LOAD); then \
> + echo "Loading $(NAME) $(loadpath)" ;\
> + $(verbose) $(LOADPOLICY) -q $(loadpath) ;\
> + else \
> + echo "Resolve binary policy configuration" ;\
> + fi
>
> ########################################
> #
>
--
Chris PeBenito