mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 10:24:11 +07:00
e9085e0ad3
Limit measuring keys to those keys being loaded onto a given set of keyrings only and when the user id (uid) matches if uid is specified in the policy. This patch defines a new IMA policy option namely "keyrings=" that can be used to specify a set of keyrings. If this option is specified in the policy for "measure func=KEY_CHECK" then only the keys loaded onto a keyring given in the "keyrings=" option are measured. If uid is specified in the policy then the key is measured only if the current user id matches the one specified in the policy. Added a new parameter namely "keyring" (name of the keyring) to process_buffer_measurement(). The keyring name is passed to ima_get_action() to determine the required action. ima_match_rules() is updated to check keyring in the policy, if specified, for KEY_CHECK function. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
128 lines
4.2 KiB
Plaintext
128 lines
4.2 KiB
Plaintext
What: security/ima/policy
|
|
Date: May 2008
|
|
Contact: Mimi Zohar <zohar@us.ibm.com>
|
|
Description:
|
|
The Trusted Computing Group(TCG) runtime Integrity
|
|
Measurement Architecture(IMA) maintains a list of hash
|
|
values of executables and other sensitive system files
|
|
loaded into the run-time of this system. At runtime,
|
|
the policy can be constrained based on LSM specific data.
|
|
Policies are loaded into the securityfs file ima/policy
|
|
by opening the file, writing the rules one at a time and
|
|
then closing the file. The new policy takes effect after
|
|
the file ima/policy is closed.
|
|
|
|
IMA appraisal, if configured, uses these file measurements
|
|
for local measurement appraisal.
|
|
|
|
rule format: action [condition ...]
|
|
|
|
action: measure | dont_measure | appraise | dont_appraise |
|
|
audit | hash | dont_hash
|
|
condition:= base | lsm [option]
|
|
base: [[func=] [mask=] [fsmagic=] [fsuuid=] [uid=]
|
|
[euid=] [fowner=] [fsname=]]
|
|
lsm: [[subj_user=] [subj_role=] [subj_type=]
|
|
[obj_user=] [obj_role=] [obj_type=]]
|
|
option: [[appraise_type=]] [template=] [permit_directio]
|
|
[appraise_flag=] [keyrings=]
|
|
base: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK]
|
|
[FIRMWARE_CHECK]
|
|
[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
|
|
[KEXEC_CMDLINE] [KEY_CHECK]
|
|
mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
|
|
[[^]MAY_EXEC]
|
|
fsmagic:= hex value
|
|
fsuuid:= file system UUID (e.g 8bcbe394-4f13-4144-be8e-5aa9ea2ce2f6)
|
|
uid:= decimal value
|
|
euid:= decimal value
|
|
fowner:= decimal value
|
|
lsm: are LSM specific
|
|
option: appraise_type:= [imasig] [imasig|modsig]
|
|
appraise_flag:= [check_blacklist]
|
|
Currently, blacklist check is only for files signed with appended
|
|
signature.
|
|
keyrings:= list of keyrings
|
|
(eg, .builtin_trusted_keys|.ima). Only valid
|
|
when action is "measure" and func is KEY_CHECK.
|
|
template:= name of a defined IMA template type
|
|
(eg, ima-ng). Only valid when action is "measure".
|
|
pcr:= decimal value
|
|
|
|
default policy:
|
|
# PROC_SUPER_MAGIC
|
|
dont_measure fsmagic=0x9fa0
|
|
dont_appraise fsmagic=0x9fa0
|
|
# SYSFS_MAGIC
|
|
dont_measure fsmagic=0x62656572
|
|
dont_appraise fsmagic=0x62656572
|
|
# DEBUGFS_MAGIC
|
|
dont_measure fsmagic=0x64626720
|
|
dont_appraise fsmagic=0x64626720
|
|
# TMPFS_MAGIC
|
|
dont_measure fsmagic=0x01021994
|
|
dont_appraise fsmagic=0x01021994
|
|
# RAMFS_MAGIC
|
|
dont_appraise fsmagic=0x858458f6
|
|
# DEVPTS_SUPER_MAGIC
|
|
dont_measure fsmagic=0x1cd1
|
|
dont_appraise fsmagic=0x1cd1
|
|
# BINFMTFS_MAGIC
|
|
dont_measure fsmagic=0x42494e4d
|
|
dont_appraise fsmagic=0x42494e4d
|
|
# SECURITYFS_MAGIC
|
|
dont_measure fsmagic=0x73636673
|
|
dont_appraise fsmagic=0x73636673
|
|
# SELINUX_MAGIC
|
|
dont_measure fsmagic=0xf97cff8c
|
|
dont_appraise fsmagic=0xf97cff8c
|
|
# CGROUP_SUPER_MAGIC
|
|
dont_measure fsmagic=0x27e0eb
|
|
dont_appraise fsmagic=0x27e0eb
|
|
# NSFS_MAGIC
|
|
dont_measure fsmagic=0x6e736673
|
|
dont_appraise fsmagic=0x6e736673
|
|
|
|
measure func=BPRM_CHECK
|
|
measure func=FILE_MMAP mask=MAY_EXEC
|
|
measure func=FILE_CHECK mask=MAY_READ uid=0
|
|
measure func=MODULE_CHECK
|
|
measure func=FIRMWARE_CHECK
|
|
appraise fowner=0
|
|
|
|
The default policy measures all executables in bprm_check,
|
|
all files mmapped executable in file_mmap, and all files
|
|
open for read by root in do_filp_open. The default appraisal
|
|
policy appraises all files owned by root.
|
|
|
|
Examples of LSM specific definitions:
|
|
|
|
SELinux:
|
|
dont_measure obj_type=var_log_t
|
|
dont_appraise obj_type=var_log_t
|
|
dont_measure obj_type=auditd_log_t
|
|
dont_appraise obj_type=auditd_log_t
|
|
measure subj_user=system_u func=FILE_CHECK mask=MAY_READ
|
|
measure subj_role=system_r func=FILE_CHECK mask=MAY_READ
|
|
|
|
Smack:
|
|
measure subj_user=_ func=FILE_CHECK mask=MAY_READ
|
|
|
|
Example of measure rules using alternate PCRs:
|
|
|
|
measure func=KEXEC_KERNEL_CHECK pcr=4
|
|
measure func=KEXEC_INITRAMFS_CHECK pcr=5
|
|
|
|
Example of appraise rule allowing modsig appended signatures:
|
|
|
|
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
|
|
|
|
Example of measure rule using KEY_CHECK to measure all keys:
|
|
|
|
measure func=KEY_CHECK
|
|
|
|
Example of measure rule using KEY_CHECK to only measure
|
|
keys added to .builtin_trusted_keys or .ima keyring:
|
|
|
|
measure func=KEY_CHECK keyrings=.builtin_trusted_keys|.ima
|