: cpucontrol module updates (stricter policy for CPU microcode updates)
PATCH 1/2 : cpucontrol module updates (stricter policy for CPU microcode updates)
cpucontrol module updates:
- introduce the file contexts according to the standard location of the most common application named microcode_ctl
(http://www.urbanmyth.org/microcode);
- add file contexts for CPUs from two different vendors, taking into consideration specific customization of the location for one distribution;
- add file contexts and declarations for the init script;
- introduce the ability to update the CPU microcode as tunable policy, as apparently such operation might modify the original licensing conditions (under some or all circumstances: "personal, non-commercial use only");
- create a new device type specifically for the CPU microcode updating functionality and modify the cpucontrol module so that such distinct new type is used for the microcode updating operation, thus leaving an open door for further modifications that distinguish different CPU-related applications/utilities to create further isolation;
- modify the interface definitions so that the CPU microcode update utility can only write and not read (unneeded) the corresponding above mentioned device type.
--- policy/modules/contrib/cpucontrol.fc | 18 +++++++++- policy/modules/contrib/cpucontrol.te | 16 ++++++++- policy/modules/kernel/devices.fc | 3 + policy/modules/kernel/devices.if | 62 +++++++++++++++++++++++++++++++---- policy/modules/kernel/devices.te | 8 +++- 5 files changed, 96 insertions(+), 11 deletions(-)
diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.fc refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.fc 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc
2012-08-09 01:13:59.615119168 +0200
@@ -1,7 +1,23 @@
+/etc/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/etc/microcode_amd\.bin --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/etc/firmware/microcode\.dat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/etc/firmware/microcode_amd.bin --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
-/etc/firmware/.* -- gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/etc/rc\.d/init\.d/microcode --gen_context(system_u:object_r:cpucontrol_initrc_exec_t,s0)
+ifdef(distro_redhat', +/lib/firmware/intel-ucode(/.*)? gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/lib/firmware/amd-ucode(/.*)? gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode\.dat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode_amd\.bat --gen_context(system_u:object_r:cpucontrol_conf_t,s0) +')
+
+/usr/sbin/microcode_ctl --gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+/usr/local/sbin/microcode_ctl --gen_context(system_u:object_r:cpucontrol_exec_t,s0) +
+ifdef(distro_redhat',
/sbin/microcode_ctl -- gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+')
/usr/sbin/cpufreqd -- gen_context(system_u:object_r:cpuspeed_exec_t,s0)
/usr/sbin/cpuspeed -- gen_context(system_u:object_r:cpuspeed_exec_t,s0)
diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.te refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.te 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te
2012-08-09 00:23:07.079532236 +0200
@@ -5,10 +5,21 @@ policy_module(cpucontrol, 1.3.0)
# Declarations
#
+## <desc>
+## <p>
+## Allow cpucontrol to upload new microcode +## to the CPU.
+## </p>
+## </desc> +gen_tunable(cpucontrol_can_upload_cpu_microcode, false) +
type cpucontrol_t;
type cpucontrol_exec_t; init_system_domain(cpucontrol_t, cpucontrol_exec_t)
+type cpucontrol_initrc_exec_t;
+init_script_file(cpucontrol_initrc_exec_t)
+
type cpucontrol_conf_t;
files_type(cpucontrol_conf_t)
@@ -37,7 +48,6 @@ kernel_read_proc_symlinks(cpucontrol_t)
kernel_read_kernel_sysctls(cpucontrol_t)
dev_read_sysfs(cpucontrol_t)
-dev_rw_cpu_microcode(cpucontrol_t)
fs_search_auto_mountpoints(cpucontrol_t)
@@ -54,6 +64,10 @@ logging_send_syslog_msg(cpucontrol_t)
userdom_dontaudit_use_unpriv_user_fds(cpucontrol_t)
+tunable_policy(cpucontrol_can_upload_cpu_microcode',
+ dev_write_cpu_microcode(cpucontrol_t)
+')
+
optional_policy(`
nscd_socket_use(cpucontrol_t)
')
diff -pruN refpolicy-08082012/policy/modules/kernel/devices.fc refpolicy-08082012-microcode/policy/modules/kernel/devices.fc
--- refpolicy-08082012/policy/modules/kernel/devices.fc 2011-12-13
12:26:37.664737865 +0100
+++ refpolicy-08082012-microcode/policy/modules/kernel/devices.fc
2012-08-08 16:09:47.217636016 +0200
@@ -63,7 +63,7 @@
/dev/mergemem -cgen_context(system_u:object_r:memory_device_t,mls_systemhigh)
/dev/mga_vid.* -c gen_context(system_u:object_r:xserver_misc_device_t,s0)
/dev/mice -c gen_context(system_u:object_r:mouse_device_t,s0)
-/dev/microcode -c gen_context(system_u:object_r:cpu_device_t,s0)
+/dev/microcode -c gen_context(system_u:object_r:cpu_microcode_device_t,s0)
/dev/midi.* -c gen_context(system_u:object_r:sound_device_t,s0)
/dev/misc/dlm.* -c gen_context(system_u:object_r:dlm_control_device_t,s0)
/dev/mixer.* -c gen_context(system_u:object_r:sound_device_t,s0)
@@ -137,6 +137,7 @@ ifdef(distro_suse',
/dev/cpu_dma_latency -cgen_context(system_u:object_r:netcontrol_device_t,s0)
/dev/cpu.* -c gen_context(system_u:object_r:cpu_device_t,s0)
+/dev/cpu/microcode -cgen_context(system_u:object_r:cpu_microcode_device_t,s0)
/dev/cpu/mtrr -c gen_context(system_u:object_r:mtrr_device_t,s0)
/dev/biometric/sensor.* -cgen_context(system_u:object_r:event_device_t,s0)
diff -pruN refpolicy-08082012/policy/modules/kernel/devices.if refpolicy-08082012-microcode/policy/modules/kernel/devices.if
--- refpolicy-08082012/policy/modules/kernel/devices.if 2012-05-29
21:13:09.426703690 +0200
+++ refpolicy-08082012-microcode/policy/modules/kernel/devices.if
2012-08-09 01:09:21.472605055 +0200
@@ -1664,7 +1664,7 @@ interface(dev_filetrans_cardmgr',
########################################
## <summary>
## Get the attributes of the CPU
-## microcode and id interfaces.
+## id interfaces.
## </summary>
## <param name="domain">
## <summary>
@@ -1682,8 +1682,27 @@ interface(dev_getattr_cpu_dev',
########################################
## <summary>
+## Get the attributes of the CPU
+## microcode interface.
+## </summary>
+## <param name="domain">
+## <summary>
+## Domain allowed access.
+## </summary>
+## </param>
+#
+interface(dev_getattr_cpu_microcode_dev',
+ gen_require(`
+ type device_t, cpu_microcode_device_t;
+ ')
+
+ getattr_chr_files_pattern($1, device_t, cpu_microcode_device_t)
+')
+
+########################################
+## <summary>
## Set the attributes of the CPU
-## microcode and id interfaces.
+## id interfaces.
## </summary>
## <param name="domain">
## <summary>
@@ -1701,6 +1720,25 @@ interface(dev_setattr_cpu_dev',
########################################
## <summary>
+## Set the attributes of the CPU
+## id interfaces.
+## </summary>
+## <param name="domain">
+## <summary>
+## Domain allowed access.
+## </summary>
+## </param>
+# +interface(dev_setattr_cpu_microcode_dev',
+ gen_require(`
+ type device_t, cpu_microcode_device_t;
+ ')
+
+ setattr_chr_files_pattern($1, device_t, cpu_microcode_device_t)
+')
+
+########################################
+## <summary>
## Read the CPU identity.
## </summary>
## <param name="domain">
@@ -1719,21 +1757,31 @@ interface(dev_read_cpuid',
########################################
## <summary>
-## Read and write the the CPU microcode device. This
-## is required to load CPU microcode.
+## Write the CPU microcode device. This
+## is required to upload the CPU microcode.
## </summary>
+## <desc>
+## <p>
+## Write the CPU microcode device.
+## This interface can be used to upload the
+## CPU microcode.
+## </p>
+## <p>
+## There might be license modifications.
+## </p>
+## </desc>
## <param name="domain">
## <summary>
## Domain allowed access.
## </summary>
## </param>
#
-interface(dev_rw_cpu_microcode',
+interface(dev_write_cpu_microcode',
gen_require(`
- type device_t, cpu_device_t;
+ type device_t, cpu_microcode_device_t;
')
- rw_chr_files_pattern($1, device_t, cpu_device_t)
+ write_chr_files_pattern($1, device_t, cpu_microcode_device_t)
')
########################################
diff -pruN refpolicy-08082012/policy/modules/kernel/devices.te refpolicy-08082012-microcode/policy/modules/kernel/devices.te
--- refpolicy-08082012/policy/modules/kernel/devices.te 2012-05-29
21:13:09.427703699 +0200
+++ refpolicy-08082012-microcode/policy/modules/kernel/devices.te
2012-08-09 00:20:34.721158261 +0200
@@ -51,12 +51,18 @@ type clock_device_t;
dev_node(clock_device_t)
#
-# cpu control devices /dev/cpu/0/*
+# cpu control devices /dev/cpu/?/*
#
type cpu_device_t;
dev_node(cpu_device_t)
#
+# cpu microcode device /dev/cpu/microcode
+#
+type cpu_microcode_device_t;
+dev_node(cpu_microcode_device_t)
+
+#
# Type for /dev/crash
#
type crash_device_t;
PATCH 1/2 : cpucontrol module updates (stricter policy for CPU microcode updates)
Quoted 53 lines · Guido Trentalancia
cpucontrol module updates:
- introduce the file contexts according to the standard location of the most common application namedmicrocode_ctl
(http://www.urbanmyth.org/microcode);
- add file contexts for CPUs from two different vendors, taking into consideration specific customization of the location for one distribution;
- add file contexts and declarations for the init script;
- introduce the ability to update the CPU microcode as tunable policy, as apparently such operation might modify the original licensing conditions (under some or all circumstances: "personal, non-commercial use only");
- create a new device type specifically for the CPU microcode updating functionality and modify the cpucontrol module so that such distinct new type is used for the microcode updating operation, thus leaving an open door for further modifications that distinguish different CPU-related applications/utilities to create further isolation;
- modify the interface definitions so that the CPU microcode update utility can only write and not read (unneeded) the corresponding above mentioned device type.Signed-off-by Guido Trentalancia <[email protected]>--- policy/modules/contrib/cpucontrol.fc | 18 +++++++++- policy/modules/contrib/cpucontrol.te | 16 ++++++++- policy/modules/kernel/devices.fc | 3 + policy/modules/kernel/devices.if | 62 +++++++++++++++++++++++++++++++---- policy/modules/kernel/devices.te | 8 +++- 5 files changed, 96 insertions(+), 11 deletions(-)diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.fc refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.fc 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc2012-08-09 01:13:59.615119168 +0200(quoted diff) +7
-1@@ -1,7 +1,23 @@ +/etc/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/microcode_amd\.bin -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/firmware/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/firmware/microcode_amd.bin -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) -/etc/firmware/.* -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/rc\.d/init\.d/microcode -- gen_context(system_u:object_r:cpucontrol_initrc_exec_t,s0) +ifdef(`distro_redhat',` +/lib/firmware/intel-ucode(/.*)?
Quoted 8 lines
gen_context(system_u:object_r:cpucontrol_conf_t,s0)+/lib/firmware/amd-ucode(/.*)?gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode\.dat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode_amd\.bat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)+')
I'm conflicted. I assume that the /etc/microcode and /etc/firmware locations are the default for this app, /lib/firmware seems more appropriate. I suspect this is not a redhat-specific location.
Quoted 4 lines
+/usr/sbin/microcode_ctl --
gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+/usr/local/sbin/microcode_ctl --gen_context(system_u:object_r:cpucontrol_exec_t,s0)
The /usr/local label is not necessary, as it will be handled by the file context path substitutions.
Quoted 3 lines
+ifdef(
distro_redhat',
/sbin/microcode_ctl--gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+')
I also don't think this change is really necessary.
Quoted 39 lines
/usr/sbin/cpufreqd--gen_context(system_u:object_r:cpuspeed_exec_t,s0)
/usr/sbin/cpuspeed--gen_context(system_u:object_r:cpuspeed_exec_t,s0)
diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.te refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.te 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te2012-08-09 00:23:07.079532236 +0200(quoted diff) +11
-1@@ -5,10 +5,21 @@ policy_module(cpucontrol, 1.3.0) # Declarations # +## <desc> +## <p> +## Allow cpucontrol to upload new microcode +## to the CPU. +## </p> +## </desc> +gen_tunable(cpucontrol_can_upload_cpu_microcode, false) + type cpucontrol_t; type cpucontrol_exec_t; init_system_domain(cpucontrol_t, cpucontrol_exec_t) +type cpucontrol_initrc_exec_t; +init_script_file(cpucontrol_initrc_exec_t) + type cpucontrol_conf_t; files_type(cpucontrol_conf_t)@@ -37,7 +48,6 @@ kernel_read_proc_symlinks(cpucontrol_t) kernel_read_kernel_sysctls(cpucontrol_t) dev_read_sysfs(cpucontrol_t) -dev_rw_cpu_microcode(cpucontrol_t) fs_search_auto_mountpoints(cpucontrol_t)
Review logging_send_syslog_msg(cpucontrol_t) · line 69
Quoted 6 lines
(quoted diff) +3
-0@@ -54,6 +64,10 @@ logging_send_syslog_msg(cpucontrol_t) userdom_dontaudit_use_unpriv_user_fds(cpucontrol_t) +tunable_policy(`cpucontrol_can_upload_cpu_microcode',` + dev_write_cpu_microcode(cpucontrol_t) +')
I don't understand why this is conditional, especially since you removed the read permission on /dev/microcode. The point of the app is to load microcode.
Signature · 3 lines
Chris PeBenito Tresys Technology, LLC www.tresys.com | oss.tresys.com
PATCH 1/2 : cpucontrol module updates (stricter policy for CPU microcode updates)
Quoted 52 lines · Christopher J. PeBenito
Quoted 51 lines · Guido Trentalancia
cpucontrol module updates:
- introduce the file contexts according to the standard location of the most common application namedmicrocode_ctl
(http://www.urbanmyth.org/microcode);
- add file contexts for CPUs from two different vendors, taking into consideration specific customization of the location for one distribution;
- add file contexts and declarations for the init script;
- introduce the ability to update the CPU microcode as tunable policy, as apparently such operation might modify the original licensing conditions (under some or all circumstances: "personal, non-commercial use only");
- create a new device type specifically for the CPU microcode updating functionality and modify the cpucontrol module so that such distinct new type is used for the microcode updating operation, thus leaving an open door for further modifications that distinguish different CPU-related applications/utilities to create further isolation;
- modify the interface definitions so that the CPU microcode update utility can only write and not read (unneeded) the corresponding above mentioned device type.Signed-off-by Guido Trentalancia <[email protected]>--- policy/modules/contrib/cpucontrol.fc | 18 +++++++++- policy/modules/contrib/cpucontrol.te | 16 ++++++++- policy/modules/kernel/devices.fc | 3 + policy/modules/kernel/devices.if | 62 +++++++++++++++++++++++++++++++---- policy/modules/kernel/devices.te | 8 +++- 5 files changed, 96 insertions(+), 11 deletions(-)diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.fc refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.fc 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc2012-08-09 01:13:59.615119168 +0200(quoted diff) +5
-1@@ -1,7 +1,23 @@ +/etc/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/microcode_amd\.bin -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/firmware/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/firmware/microcode_amd.bin -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) -/etc/firmware/.* -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/rc\.d/init\.d/microcode -- gen_context(system_u:object_r:cpucontrol_initrc_exec_t,s0)
Quoted 12 lines
Quoted 10 lines
(quoted diff) +2
-0+ifdef(`distro_redhat',` +/lib/firmware/intel-ucode(/.*)?
gen_context(system_u:object_r:cpucontrol_conf_t,s0)+/lib/firmware/amd-ucode(/.*)?gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode\.dat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode_amd\.bat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)+')I'm conflicted. I assume that the
/etc/microcodeand/etc/firmwarelocations are the default for this app,/lib/firmwareseems more appropriate. I suspect this is not a redhat-specific location.
As far as I remember the /etc/firmware location was originally chosen by one distribution (maybe Fedora, I can't remember exactly the details).
If that is removed, it might break compatibility with previous releases. Latest location chosen by Fedora should probably be /lib/firmware with the variants included in the ifdef distro block.
Quoted 6 lines
Quoted 4 lines
+/usr/sbin/microcode_ctl --
gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+/usr/local/sbin/microcode_ctl --gen_context(system_u:object_r:cpucontrol_exec_t,s0)The
/usr/locallabel is not necessary, as it will be handled by the file context path substitutions.
I wasn't sure how to proceed, /usr/local/sbin is the original default location chosen by the unedited application's Makefile...
As for the other vendor, the specific application should be called "ucodeadm" and I've included that with the /usr/sbin prefix in the next version of the patch that I am preparing.
Quoted 5 lines
Quoted 3 lines
+ifdef(
distro_redhat',
/sbin/microcode_ctl--gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+')I also don't think this change is really necessary.
I don't know. It probably got there from some brief research carried out on recent Fedora builds...
But, if it's unneeded, I'll remove it in the next version that I'll post as soon as possible with the other required amendments.
Quoted 40 lines
Quoted 40 lines
/usr/sbin/cpufreqd -- gen_context(system_u:object_r:cpuspeed_exec_t,s0) /usr/sbin/cpuspeed -- gen_context(system_u:object_r:cpuspeed_exec_t,s0)diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.te refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.te 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te2012-08-09 00:23:07.079532236 +0200(quoted diff) +11
-1@@ -5,10 +5,21 @@ policy_module(cpucontrol, 1.3.0) # Declarations # +## <desc> +## <p> +## Allow cpucontrol to upload new microcode +## to the CPU. +## </p> +## </desc> +gen_tunable(cpucontrol_can_upload_cpu_microcode, false) + type cpucontrol_t; type cpucontrol_exec_t; init_system_domain(cpucontrol_t, cpucontrol_exec_t) +type cpucontrol_initrc_exec_t; +init_script_file(cpucontrol_initrc_exec_t) + type cpucontrol_conf_t; files_type(cpucontrol_conf_t)@@ -37,7 +48,6 @@ kernel_read_proc_symlinks(cpucontrol_t) kernel_read_kernel_sysctls(cpucontrol_t) dev_read_sysfs(cpucontrol_t) -dev_rw_cpu_microcode(cpucontrol_t) fs_search_auto_mountpoints(cpucontrol_t)@@ -54,6 +64,10 @@ logging_send_syslog_msg(cpucontrol_t)
Quoted 7 lines
Review logging_send_syslog_msg(cpucontrol_t) · line 69
Quoted 5 lines
(quoted diff) +3
-0userdom_dontaudit_use_unpriv_user_fds(cpucontrol_t) +tunable_policy(`cpucontrol_can_upload_cpu_microcode',` + dev_write_cpu_microcode(cpucontrol_t) +')I don't understand why this is conditional, especially since you removed the read permission on
/dev/microcode. The point of the app is to load microcode.
Conditional because not everyone might want that to happen. For example, one issue might be the licensing one.
It shall add more configurability.
Best regards,
Guido
PATCH 1/2 : cpucontrol module updates (stricter policy for CPU microcode updates)
In reply to Christopher J. PeBenitoHello.
Here is a revised version (1/1) of the patch for the cpucontrol module.
Quoted 5 lines · Christopher J. PeBenito
Quoted 4 lines · Guido Trentalancia
cpucontrol module updates:
- introduce the file contexts according to the standard location of the most common application namedmicrocode_ctl
(http://www.urbanmyth.org/microcode);
Dropped as risky. Can be tackled at a later time or by users/distributions individually.
Quoted 3 lines
Quoted 3 lines
- add file contexts for CPUs from two different vendors, taking into consideration specific customization of the location for one distribution;
Not taking anymore into consideration binary location customizations as too risky. Only adding generic support for the most likely location of the application provided by the other manufacturer.
Quoted 110 lines
Quoted 46 lines
- add file contexts and declarations for the init script;
- introduce the ability to update the CPU microcode as tunable policy, as apparently such operation might modify the original licensing conditions (under some or all circumstances: "personal, non-commercial use only");
- create a new device type specifically for the CPU microcode updating functionality and modify the cpucontrol module so that such distinct new type is used for the microcode updating operation, thus leaving an open door for further modifications that distinguish different CPU-related applications/utilities to create further isolation;
- modify the interface definitions so that the CPU microcode update utility can only write and not read (unneeded) the corresponding above mentioned device type.Signed-off-by Guido Trentalancia <[email protected]>--- policy/modules/contrib/cpucontrol.fc | 18 +++++++++- policy/modules/contrib/cpucontrol.te | 16 ++++++++- policy/modules/kernel/devices.fc | 3 + policy/modules/kernel/devices.if | 62 +++++++++++++++++++++++++++++++---- policy/modules/kernel/devices.te | 8 +++- 5 files changed, 96 insertions(+), 11 deletions(-)diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.fc refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.fc 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.fc2012-08-09 01:13:59.615119168 +0200(quoted diff) +7
-1@@ -1,7 +1,23 @@ +/etc/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/microcode_amd\.bin -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/firmware/microcode\.dat -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/firmware/microcode_amd.bin -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) -/etc/firmware/.* -- gen_context(system_u:object_r:cpucontrol_conf_t,s0) +/etc/rc\.d/init\.d/microcode -- gen_context(system_u:object_r:cpucontrol_initrc_exec_t,s0) +ifdef(`distro_redhat',` +/lib/firmware/intel-ucode(/.*)?Quoted 8 lines
gen_context(system_u:object_r:cpucontrol_conf_t,s0)+/lib/firmware/amd-ucode(/.*)?gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode\.dat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/lib/firmware/microcode_amd\.bat --gen_context(system_u:object_r:cpucontrol_conf_t,s0)+')I'm conflicted. I assume that the
/etc/microcodeand/etc/firmwarelocations are the default for this app,/lib/firmwareseems more appropriate. I suspect this is not a redhat-specific location.Quoted 4 lines
+/usr/sbin/microcode_ctl --
gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+/usr/local/sbin/microcode_ctl --gen_context(system_u:object_r:cpucontrol_exec_t,s0)The
/usr/locallabel is not necessary, as it will be handled by the file context path substitutions.Quoted 3 lines
+ifdef(
distro_redhat',
/sbin/microcode_ctl--gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+')I also don't think this change is really necessary.
Quoted 40 lines
/usr/sbin/cpufreqd -- gen_context(system_u:object_r:cpuspeed_exec_t,s0) /usr/sbin/cpuspeed -- gen_context(system_u:object_r:cpuspeed_exec_t,s0)diff -pruN refpolicy-08082012/policy/modules/contrib/cpucontrol.te refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te
--- refpolicy-08082012/policy/modules/contrib/cpucontrol.te 2011-09-09
18:29:23.563610858 +0200
+++ refpolicy-08082012-microcode/policy/modules/contrib/cpucontrol.te2012-08-09 00:23:07.079532236 +0200(quoted diff) +11
-1@@ -5,10 +5,21 @@ policy_module(cpucontrol, 1.3.0) # Declarations # +## <desc> +## <p> +## Allow cpucontrol to upload new microcode +## to the CPU. +## </p> +## </desc> +gen_tunable(cpucontrol_can_upload_cpu_microcode, false) + type cpucontrol_t; type cpucontrol_exec_t; init_system_domain(cpucontrol_t, cpucontrol_exec_t) +type cpucontrol_initrc_exec_t; +init_script_file(cpucontrol_initrc_exec_t) + type cpucontrol_conf_t; files_type(cpucontrol_conf_t)@@ -37,7 +48,6 @@ kernel_read_proc_symlinks(cpucontrol_t) kernel_read_kernel_sysctls(cpucontrol_t) dev_read_sysfs(cpucontrol_t) -dev_rw_cpu_microcode(cpucontrol_t) fs_search_auto_mountpoints(cpucontrol_t)@@ -54,6 +64,10 @@ logging_send_syslog_msg(cpucontrol_t)
Quoted 7 lines
Review logging_send_syslog_msg(cpucontrol_t) · line 69
Quoted 5 lines
(quoted diff) +3
-0userdom_dontaudit_use_unpriv_user_fds(cpucontrol_t) +tunable_policy(`cpucontrol_can_upload_cpu_microcode',` + dev_write_cpu_microcode(cpucontrol_t) +')I don't understand why this is conditional, especially since you removed the read permission on
/dev/microcode. The point of the app is to load microcode.
diff -pruN refpolicy-09082012-git-master/policy/modules/contrib/cpucontrol.fc refpolicy-09082012-microcode-v3/policy/modules/contrib/cpucontrol.fc --- refpolicy-09082012-git-master/policy/modules/contrib/cpucontrol.fc Thu Aug 23 19:22:59 2012
+++
refpolicy-09082012-microcode-v3/policy/modules/contrib/cpucontrol.fc Sat
Sep 8 10:16:21 2012
@@ -1,7 +1,12 @@
-
/etc/firmware/.* -- gen_context(system_u:object_r:cpucontrol_conf_t,s0)
+/etc/rc\.d/init\.d/microcode --gen_context(system_u:object_r:cpucontrol_conf_t,s0) +
+# Intel(R) devices supporting application
/sbin/microcode_ctl -- gen_context(system_u:object_r:cpucontrol_exec_t,s0)
+
+# AMD(tm) devices application
+/sbin/ucodeadm -- gen_context(system_u:object_r:cpucontrol_exec_t,s0)
/usr/sbin/cpufreqd -- gen_context(system_u:object_r:cpuspeed_exec_t,s0)
/usr/sbin/cpuspeed -- gen_context(system_u:object_r:cpuspeed_exec_t,s0)
diff -pruN refpolicy-09082012-git-master/policy/modules/contrib/cpucontrol.te refpolicy-09082012-microcode-v3/policy/modules/contrib/cpucontrol.te --- refpolicy-09082012-git-master/policy/modules/contrib/cpucontrol.te Thu Aug 23 19:22:59 2012
+++
refpolicy-09082012-microcode-v3/policy/modules/contrib/cpucontrol.te Sat
Sep 8 10:10:55 2012
@@ -5,10 +5,21 @@ policy_module(cpucontrol, 1.3.0)
# Declarations
#
+## <desc>
+## <p>
+## Allow cpucontrol to upload new microcode +## to the CPU.
+## </p>
+## </desc> +gen_tunable(cpucontrol_can_upload_cpu_microcode, false) +
type cpucontrol_t;
type cpucontrol_exec_t; init_system_domain(cpucontrol_t, cpucontrol_exec_t)
+type cpucontrol_initrc_exec_t;
+init_script_file(cpucontrol_initrc_exec_t)
+
type cpucontrol_conf_t;
files_type(cpucontrol_conf_t)
@@ -37,7 +48,6 @@ kernel_read_proc_symlinks(cpucontrol_t)
kernel_read_kernel_sysctls(cpucontrol_t)
dev_read_sysfs(cpucontrol_t)
-dev_rw_cpu_microcode(cpucontrol_t)
fs_search_auto_mountpoints(cpucontrol_t)
@@ -53,6 +63,10 @@ init_use_script_ptys(cpucontrol_t)
logging_send_syslog_msg(cpucontrol_t)
userdom_dontaudit_use_unpriv_user_fds(cpucontrol_t)
+ +tunable_policy(cpucontrol_can_upload_cpu_microcode',
+ dev_write_cpu_microcode(cpucontrol_t)
+')
optional_policy(`
nscd_socket_use(cpucontrol_t)
diff -pruN refpolicy-09082012-git-master/policy/modules/kernel/devices.fc refpolicy-09082012-microcode-v3/policy/modules/kernel/devices.fc
--- refpolicy-09082012-git-master/policy/modules/kernel/devices.fc Thu
Sep 6 10:50:18 2012 +++ refpolicy-09082012-microcode-v3/policy/modules/kernel/devices.fc Sat Sep 8 10:10:55 2012
@@ -65,7 +65,7 @@
/dev/mergemem -cgen_context(system_u:object_r:memory_device_t,mls_systemhigh)
/dev/mga_vid.* -c gen_context(system_u:object_r:xserver_misc_device_t,s0)
/dev/mice -c gen_context(system_u:object_r:mouse_device_t,s0)
-/dev/microcode -c gen_context(system_u:object_r:cpu_device_t,s0)
+/dev/microcode -c gen_context(system_u:object_r:cpu_microcode_device_t,s0)
/dev/midi.* -c gen_context(system_u:object_r:sound_device_t,s0)
/dev/misc/dlm.* -c gen_context(system_u:object_r:dlm_control_device_t,s0)
/dev/mixer.* -c gen_context(system_u:object_r:sound_device_t,s0)
@@ -139,6 +139,7 @@ ifdef(distro_suse',
/dev/cpu_dma_latency -cgen_context(system_u:object_r:netcontrol_device_t,s0)
/dev/cpu.* -c gen_context(system_u:object_r:cpu_device_t,s0)
+/dev/cpu/microcode -cgen_context(system_u:object_r:cpu_microcode_device_t,s0)
/dev/cpu/mtrr -c gen_context(system_u:object_r:mtrr_device_t,s0)
/dev/biometric/sensor.* -cgen_context(system_u:object_r:event_device_t,s0)
diff -pruN refpolicy-09082012-git-master/policy/modules/kernel/devices.if refpolicy-09082012-microcode-v3/policy/modules/kernel/devices.if
--- refpolicy-09082012-git-master/policy/modules/kernel/devices.if Thu
Aug 23 19:16:55 2012 +++ refpolicy-09082012-microcode-v3/policy/modules/kernel/devices.if Sat Sep 8 10:10:55 2012
@@ -1664,7 +1664,7 @@ interface(dev_filetrans_cardmgr',
########################################
## <summary>
## Get the attributes of the CPU
-## microcode and id interfaces.
+## id interfaces.
## </summary>
## <param name="domain">
## <summary>
@@ -1682,8 +1682,27 @@ interface(dev_getattr_cpu_dev',
########################################
## <summary>
+## Get the attributes of the CPU
+## microcode interface.
+## </summary>
+## <param name="domain">
+## <summary>
+## Domain allowed access.
+## </summary>
+## </param>
+#
+interface(dev_getattr_cpu_microcode_dev',
+ gen_require(`
+ type device_t, cpu_microcode_device_t;
+ ')
+
+ getattr_chr_files_pattern($1, device_t, cpu_microcode_device_t)
+')
+
+########################################
+## <summary>
## Set the attributes of the CPU
-## microcode and id interfaces.
+## id interfaces.
## </summary>
## <param name="domain">
## <summary>
@@ -1701,6 +1720,25 @@ interface(dev_setattr_cpu_dev',
########################################
## <summary>
+## Set the attributes of the CPU
+## id interfaces.
+## </summary>
+## <param name="domain">
+## <summary>
+## Domain allowed access.
+## </summary>
+## </param>
+# +interface(dev_setattr_cpu_microcode_dev',
+ gen_require(`
+ type device_t, cpu_microcode_device_t;
+ ')
+
+ setattr_chr_files_pattern($1, device_t, cpu_microcode_device_t)
+')
+
+########################################
+## <summary>
## Read the CPU identity.
## </summary>
## <param name="domain">
@@ -1719,21 +1757,31 @@ interface(dev_read_cpuid',
########################################
## <summary>
-## Read and write the the CPU microcode device. This
-## is required to load CPU microcode.
+## Write the CPU microcode device. This
+## is required to upload the CPU microcode.
## </summary>
+## <desc>
+## <p>
+## Write the CPU microcode device.
+## This interface can be used to upload the
+## CPU microcode.
+## </p>
+## <p>
+## There might be license modifications.
+## </p>
+## </desc>
## <param name="domain">
## <summary>
## Domain allowed access.
## </summary>
## </param>
#
-interface(dev_rw_cpu_microcode',
+interface(dev_write_cpu_microcode',
gen_require(`
- type device_t, cpu_device_t;
+ type device_t, cpu_microcode_device_t;
')
- rw_chr_files_pattern($1, device_t, cpu_device_t)
+ write_chr_files_pattern($1, device_t, cpu_microcode_device_t)
')
########################################
diff -pruN refpolicy-09082012-git-master/policy/modules/kernel/devices.te refpolicy-09082012-microcode-v3/policy/modules/kernel/devices.te
--- refpolicy-09082012-git-master/policy/modules/kernel/devices.te Thu
Sep 6 10:50:18 2012 +++ refpolicy-09082012-microcode-v3/policy/modules/kernel/devices.te Sat Sep 8 10:10:55 2012
@@ -51,10 +51,16 @@ type clock_device_t;
dev_node(clock_device_t)
#
-# cpu control devices /dev/cpu/0/*
+# cpu control devices /dev/cpu/?/*
#
type cpu_device_t;
dev_node(cpu_device_t)
+
+#
+# cpu microcode device /dev/cpu/microcode
+#
+type cpu_microcode_device_t;
+dev_node(cpu_microcode_device_t)
#
# Type for /dev/crash
PATCH 1/2 : cpucontrol module updates (stricter policy for CPU microcode updates)
Quoted 14 lines · Guido Trentalancia
Hello.
Here is a revised version (1/1) of the patch for the cpucontrol module.
Quoted 5 lines · Christopher J. PeBenito
Quoted 4 lines · Guido Trentalancia
cpucontrol module updates:
- introduce the file contexts according to the standard location of the most common application namedmicrocode_ctl
(http://www.urbanmyth.org/microcode);Dropped as risky. Can be tackled at a later time or by users/distributions individually.
Quoted 22 lines
Quoted 3 lines
Quoted 3 lines
- add file contexts for CPUs from two different vendors, taking into consideration specific customization of the location for one distribution;
Not taking anymore into consideration binary location customizations as too risky. Only adding generic support for the most likely location of the application provided by the other manufacturer.
Quoted 14 lines
Quoted 14 lines
- add file contexts and declarations for the init script;
- introduce the ability to update the CPU microcode as tunable policy, as apparently such operation might modify the original licensing conditions (under some or all circumstances: "personal, non-commercial use only");
- create a new device type specifically for the CPU microcode updating functionality and modify the cpucontrol module so that such distinct new type is used for the microcode updating operation, thus leaving an open door for further modifications that distinguish different CPU-related applications/utilities to create further isolation;
- modify the interface definitions so that the CPU microcode update utility can only write and not read (unneeded) the corresponding above mentioned device type.
Before I can commit this, I need an answer for this previous question:
Quoted 17 lines
Quoted 17 lines
Quoted 9 lines
(quoted diff) +0
-1@@ -37,7 +48,6 @@ kernel_read_proc_symlinks(cpucontrol_t) kernel_read_kernel_sysctls(cpucontrol_t) dev_read_sysfs(cpucontrol_t) -dev_rw_cpu_microcode(cpucontrol_t) fs_search_auto_mountpoints(cpucontrol_t)Review logging_send_syslog_msg(cpucontrol_t) · line 69
Quoted 6 lines
(quoted diff) +3
-0@@ -54,6 +64,10 @@ logging_send_syslog_msg(cpucontrol_t) userdom_dontaudit_use_unpriv_user_fds(cpucontrol_t) +tunable_policy(`cpucontrol_can_upload_cpu_microcode',` + dev_write_cpu_microcode(cpucontrol_t) +')I don't understand why this is conditional, especially since you removed the read permission on
/dev/microcode. The point of the app is to load microcode.
Signature · 3 lines
Chris PeBenito Tresys Technology, LLC www.tresys.com | oss.tresys.com