![Mimi Zohar](/assets/img/avatar_default.png)
Support for a user loadable policy through securityfs with support for LSM specific policy data. - free invalid rule in ima_parse_add_rule() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
62 lines
1.9 KiB
Text
62 lines
1.9 KiB
Text
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.
|
|
|
|
rule format: action [condition ...]
|
|
|
|
action: measure | dont_measure
|
|
condition:= base | lsm
|
|
base: [[func=] [mask=] [fsmagic=] [uid=]]
|
|
lsm: [[subj_user=] [subj_role=] [subj_type=]
|
|
[obj_user=] [obj_role=] [obj_type=]]
|
|
|
|
base: func:= [BPRM_CHECK][FILE_MMAP][INODE_PERMISSION]
|
|
mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC]
|
|
fsmagic:= hex value
|
|
uid:= decimal value
|
|
lsm: are LSM specific
|
|
|
|
default policy:
|
|
# PROC_SUPER_MAGIC
|
|
dont_measure fsmagic=0x9fa0
|
|
# SYSFS_MAGIC
|
|
dont_measure fsmagic=0x62656572
|
|
# DEBUGFS_MAGIC
|
|
dont_measure fsmagic=0x64626720
|
|
# TMPFS_MAGIC
|
|
dont_measure fsmagic=0x01021994
|
|
# SECURITYFS_MAGIC
|
|
dont_measure fsmagic=0x73636673
|
|
|
|
measure func=BPRM_CHECK
|
|
measure func=FILE_MMAP mask=MAY_EXEC
|
|
measure func=INODE_PERM mask=MAY_READ uid=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 inode_permission.
|
|
|
|
Examples of LSM specific definitions:
|
|
|
|
SELinux:
|
|
# SELINUX_MAGIC
|
|
dont_measure fsmagic=0xF97CFF8C
|
|
|
|
dont_measure obj_type=var_log_t
|
|
dont_measure obj_type=auditd_log_t
|
|
measure subj_user=system_u func=INODE_PERM mask=MAY_READ
|
|
measure subj_role=system_r func=INODE_PERM mask=MAY_READ
|
|
|
|
Smack:
|
|
measure subj_user=_ func=INODE_PERM mask=MAY_READ
|