The Linux Integrity Module (LIM) Framework provides hooks
for modules to perform collection, appraisal, and storage
of system integrity measurements. One such module, IMA,
collects measurements of file data, maintains this list
in the kernel, and if available, stores (extends) the
measurements into a hardware TPM. These measurements are
collected, appraised, and stored before any access
(read or execute) to the data, so that malicious code or
data cannot remove or cover up its own measurement, to avoid
detection. If the measurements are anchored in a TPM, the
TPM can sign the measurements, for proof of integrity
to a third party, such as in enterprise client management.
Integrity measurement is complementary to LSM mandatory
access control, which can be used to protect the integrity
of system files. Integrity measurement policies can take
advantage of LSM labels in deciding what to measure and
to detect when the protection fails, with hardware strength.
This patch set addresses a couple of concerns raised on
the mailing list:
- Uses a radix tree to store integrity information
associated with an inode, instead of extending the
inode structure.
- Moves hooks out of vfs_permission and file_permission,
which are deprecated.
- Fixes the template list locking.
- Updates and clarifies the integrity_audit kernel
command line option.
Dave Safford
Mimi Zohar (4):
integrity: TPM internel kernel interface
integrity: Linux Integrity Module(LIM)
integrity: IMA as an integrity service provider
integrity: IMA radix tree
This version stores integrity information associated with an inode
in a radix tree in order to avoid bloating the in memory inode.
As entries can not be added to the radix tree at security_initcall,
this version removes the dual stage initialization. Allocating and
freeing the memory continues to be done at inode_alloc and file_free,
respectively, except for inodes created before late_initcall.
Signed-off-by: Mimi Zohar <[email protected]>
---
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bc6460c..0dcdd94 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -683,9 +683,6 @@ struct inode {
#ifdef CONFIG_SECURITY
void *i_security;
#endif
-#ifdef CONFIG_INTEGRITY
- void *i_integrity;
-#endif
void *i_private; /* fs or device private pointer */
};
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index f3aced4..959ae66 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -6,4 +6,4 @@
obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
- ima_policy.o
+ ima_policy.o ima_iint.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 9a24305..09a5e1a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -92,7 +92,6 @@ void ima_store_measurement(void *d);
void ima_template_show(struct seq_file *m, void *e,
enum integrity_show_type show);
-
/*
* used to protect h_table and sha_table
*/
@@ -109,7 +108,7 @@ extern struct ima_h_table ima_htable;
static inline unsigned long IMA_HASH_KEY(u8 *digest)
{
- return(hash_long(*digest, IMA_HASH_BITS));
+ return (hash_long(*digest, IMA_HASH_BITS));
}
/* TPM "Glue" definitions */
@@ -145,11 +144,36 @@ struct ima_iint_cache {
u8 hmac[IMA_DIGEST_SIZE];
u8 digest[IMA_DIGEST_SIZE];
struct mutex mutex;
+ atomic_t refcount;
};
#define IMA_IINT_INIT 1
#define IMA_MUST_MEASURE 2
#define IMA_MEASURED 4
+void ima_iint_init(void);
+struct ima_iint_cache * ima_iint_lookup(struct inode *inode);
+int ima_iint_insert(struct inode *inode);
+void ima_iint_delete(struct inode *inode);
+
+static inline void iint_get(struct ima_iint_cache *iint)
+{
+ atomic_inc(&iint->refcount);
+}
+
+/*
+ * When iint->refcounter goes to 0, free iint.
+ *
+ * When inode_alloc_integrity starts at late_initcall,
+ * iint can be NULl.
+ */
+static inline void iint_put(struct ima_iint_cache *iint)
+{
+ if (!iint)
+ return;
+ if (atomic_dec_and_test(&iint->refcount))
+ kfree(iint);
+}
+
/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 504c195..5b0b2f9 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -266,9 +266,35 @@ int ima_must_measure(void *template_data)
if (skip_measurement(data->inode, data->mask))
return -EPERM;
- iint = inode->i_integrity;
- mutex_lock(&iint->mutex);
+ rcu_read_lock();
+ iint = ima_iint_lookup(inode);
+ if (iint)
+ iint_get(iint);
+ rcu_read_unlock();
+
+ if (!iint) {
+ int rc;
+
+ /* Most insertions are done at inode_alloc,
+ * except those allocated before late_initcall.
+ * Can't initialize at security_initcall,
+ * got to wait at least until proc_init.
+ */
+ rc = ima_iint_insert(inode);
+ if (rc < 0)
+ return rc;
+
+ rcu_read_lock();
+ iint = ima_iint_lookup(inode);
+ if (!iint) {
+ rcu_read_unlock();
+ return -ENOMEM;
+ }
+ iint_get(iint);
+ rcu_read_unlock();
+ }
+ mutex_lock(&iint->mutex);
/* short circuit out of here, if iint initialized
* and either no measurement required or already measured.
*/
@@ -290,6 +316,7 @@ int ima_must_measure(void *template_data)
iint->flags |= IMA_IINT_INIT;
}
mutex_unlock(&iint->mutex);
+ iint_put(iint);
return must_measure;
}
@@ -314,7 +341,15 @@ int ima_collect_measurement(void *template_data)
if (!inode || !dentry)
return -EINVAL;
- iint = inode->i_integrity;
+ rcu_read_lock();
+ iint = ima_iint_lookup(inode);
+ if (!iint) {
+ rcu_read_unlock();
+ return -ENOMEM;
+ }
+ iint_get(iint);
+ rcu_read_unlock();
+
mutex_lock(&iint->mutex);
if (!(iint->flags & IMA_MEASURED)) {
memset(iint->digest, 0, IMA_DIGEST_SIZE);
@@ -322,6 +357,7 @@ int ima_collect_measurement(void *template_data)
} else
result = -EEXIST;
mutex_unlock(&iint->mutex);
+ iint_put(iint);
return result;
}
@@ -344,7 +380,15 @@ void ima_store_measurement(void *template_data)
struct ima_args_data *data = &idata->data.args;
struct ima_iint_cache *iint;
- iint = data->inode->i_integrity;
+ rcu_read_lock();
+ iint = ima_iint_lookup(data->inode);
+ if (!iint) {
+ rcu_read_unlock();
+ return;
+ }
+ iint_get(iint);
+ rcu_read_unlock();
+
mutex_lock(&iint->mutex);
if (iint->flags & IMA_MEASURED) {
mutex_unlock(&iint->mutex);
@@ -358,6 +402,7 @@ void ima_store_measurement(void *template_data)
iint->version = data->inode->i_version;
}
mutex_unlock(&iint->mutex);
+ iint_put(iint);
} else if (idata->type == IMA_TEMPLATE) {
struct ima_store_data *template = (struct ima_store_data *)
&idata->data.template;
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
new file mode 100644
index 0000000..f7f6673
--- /dev/null
+++ b/security/integrity/ima/ima_iint.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_iint.c
+ * cache integrity information associated with an inode
+ * using a radix tree.
+ */
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/radix-tree.h>
+#include "ima.h"
+
+static struct radix_tree_root ima_iint_store;
+DEFINE_SPINLOCK(ima_iint_lock);
+
+void ima_iint_init(void)
+{
+ INIT_RADIX_TREE(&ima_iint_store, GFP_ATOMIC);
+}
+
+/* Call with rcu_read_lock */
+struct ima_iint_cache * ima_iint_lookup(struct inode *inode)
+{
+ return radix_tree_lookup(&ima_iint_store, (unsigned long)inode);
+}
+
+int ima_iint_insert(struct inode *inode)
+{
+ struct ima_iint_cache *iint;
+ int rc = 0;
+
+ iint = kzalloc(sizeof(*iint), GFP_KERNEL);
+ if (!iint)
+ return -ENOMEM;
+ mutex_init(&iint->mutex);
+ atomic_set(&iint->refcount, 1);
+ iint->version = inode->i_version;
+
+ if ((rc = radix_tree_preload(GFP_KERNEL)) < 0) {
+ printk(KERN_INFO "%s: radix_tree_preload\n", __FUNCTION__);
+ kfree(iint);
+ return rc;
+ }
+
+ spin_lock(&ima_iint_lock);
+ rc = radix_tree_insert(&ima_iint_store, (unsigned long)inode, iint);
+ spin_unlock(&ima_iint_lock);
+ radix_tree_preload_end();
+ return rc;
+}
+
+void ima_iint_delete(struct inode *inode)
+{
+ struct ima_iint_cache *iint;
+
+ spin_lock(&ima_iint_lock);
+ iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
+ spin_unlock(&ima_iint_lock);
+ iint_put(iint);
+}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2b90df9..e36eef8 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -28,7 +28,6 @@
#include "ima.h"
-static bool ima_initialized = false;
char *ima_hash = "sha1";
static int __init hash_setup(char *str)
{
@@ -102,32 +101,32 @@ static void ima_file_free(struct file *file)
return;
if ((file->f_mode & FMODE_WRITE) &&
(atomic_read(&inode->i_writecount) == 1)) {
- iint = inode->i_integrity;
+ rcu_read_lock();
+ iint = ima_iint_lookup(inode);
+ if (!iint) {
+ rcu_read_unlock();
+ return;
+ }
+ iint_get(iint);
+ rcu_read_unlock();
+
mutex_lock(&iint->mutex);
if (iint->version != inode->i_version)
iint->flags &= ~IMA_MEASURED;
mutex_unlock(&iint->mutex);
+ iint_put(iint);
}
}
/**
- * ima_alloc_integrity - allocate and attach an integrity structure
+ * ima_alloc_integrity - allocate and insert an integrity structure
* @inode: the inode structure
*
* Returns 0 on success, -ENOMEM on failure
*/
static int ima_inode_alloc_integrity(struct inode *inode)
{
- struct ima_iint_cache *iint;
-
- iint = kzalloc(sizeof(*iint), GFP_KERNEL);
- if (!iint)
- return -ENOMEM;
-
- mutex_init(&iint->mutex);
- inode->i_integrity = iint;
- iint->version = inode->i_version;
- return 0;
+ return ima_iint_insert(inode);
}
/**
@@ -136,12 +135,7 @@ static int ima_inode_alloc_integrity(struct inode *inode)
*/
static void ima_inode_free_integrity(struct inode *inode)
{
- struct ima_iint_cache *iint = inode->i_integrity;
-
- if (iint) {
- inode->i_integrity = NULL;
- kfree(iint);
- }
+ ima_iint_delete(inode);
}
/**
@@ -168,9 +162,6 @@ static int ima_nameidata_check_integrity(struct nameidata *nd, int mask)
struct dentry *dentry;
struct inode *inode;
- if (!ima_initialized)
- return 0;
-
memset(&idata, 0, sizeof idata);
ima_fixup_argsdata(data, NULL, &nd->path, mask, INODE_PERMISSION);
inode = data->inode;
@@ -238,8 +229,6 @@ static int ima_file_mmap(struct file *file, unsigned long prot)
struct ima_args_data *data = &idata.data.args;
int rc = 0;
- if (!ima_initialized)
- return 0;
if (!file || !file->f_dentry)
return rc;
if (!(prot & VM_EXEC))
@@ -279,8 +268,6 @@ static int ima_bprm_check_integrity(struct linux_binprm *bprm)
struct ima_args_data *data = &idata.data.args;
int rc = 0;
- if (!ima_initialized)
- return 0;
ima_fixup_argsdata(data, bprm->file, NULL, MAY_EXEC, BPRM_CHECK);
data->filename = bprm->filename;
@@ -309,30 +296,24 @@ static const struct integrity_operations ima_base_ops = {
.file_free_integrity = ima_file_free,
};
-/* Register the integrity ops early so that i_integrity is
- * allocated at inode initialization.
+/* After the TPM is available, start IMA
*/
-static int __init init_ops(void)
+static int __init init_ima(void)
{
int error;
+ ima_iint_init(); /* Can't register early when using radix_tree */
+ error = ima_init();
+ if (error)
+ goto out;
+
if (ima_base_hooks)
error = register_integrity(&ima_base_ops);
else
error = register_integrity(&ima_integrity_ops);
- return error;
-}
-
-/* After the TPM is available, start IMA
- */
-static int __init init_ima(void)
-{
- int error;
-
- error = ima_init();
if (error)
goto out;
- ima_initialized = true;
+
integrity_register_template("ima", &ima_template_ops);
out:
return error;
@@ -345,7 +326,6 @@ static void __exit cleanup_ima(void)
ima_cleanup();
}
-security_initcall(init_ops); /* Register the integrity ops early */
late_initcall(init_ima); /* Start IMA after the TPM is available */
module_exit(cleanup_ima);
--
1.5.5.1
This is a re-release of Integrity Measurement Architecture(IMA) as an
independent Linunx Integrity Module(LIM) service provider.
As a LIM integrity provider, IMA implements the new LIM must_measure(),
collect_measurement(), store_measurement(), and display_template() API
calls. The store_measurement() call supports two types of data, IMA
(i.e. file data) and generic template data.
IMA provides hardware (TPM) based measurement and attestation for both
files and other types of template measurements. As the Trusted Computing
(TPM) model requires, IMA measures all files before they are accessed
in any way (on the bprm_check_integrity, nameidata_check_integrity,
file_mmap hooks), and commits the measurements to the TPM. In addition,
IMA maintains a list of these hash values, which can be used to validate
the aggregate PCR value. The TPM can sign these measurements, and thus
the system can prove to itself and to a third party these measurements
in a way that cannot be circumvented by malicious or compromised software.
When store_measurement() is called for the IMA type of data, the file
measurement and the file name hint are used to form an IMA template.
IMA then calculates the IMA template measurement(hash) and submits it
to the TPM chip for inclusion in one of the chip's Platform Configuration
Registers (PCR).
When store_measurement() is called for generic template data, IMA
calculates the measurement(hash) of the template data, and submits
the template measurement to the TPM chip for inclusion in one of the
chip's Platform Configuration Registers(PCR).
In order to view the contents of template data through securityfs, the
template_display() function must be defined in the registered
template_operations. In the case of the IMA template, the list of
file names and files hashes submitted can be viewed through securityfs.
As mentioned above, IMA maintains a list of hash values of executables
and other sensitive system files loaded into the run-time of the system.
Our work has shown that requests for integrity appraisal and measurement
need to be based on knowledge of the filesystem, requiring the system
to either be labeled with integrity data or depend on the existent LSM
security labels. The previous set of integrity patches modified the LSM
modules to be integrity context aware, meaning that the LSM modules made
integrity data/metadata appraisal and measurement API calls based on
an understanding of the LSM security labels. Both of the LSM maintainers
felt that the changes were too intrusive and that integrity enforcement
should be made by the integrity provider, not the LSM module.
To address these concerns, Stephen Smalley suggested using the
security_audit_rule_match(), renamed to security_filter_rule_match(), to
define LSM specific integrity measurement policy rules, in lieu of
modifying the LSM modules. In the current set of patches, the integrity
API calls can be made either by IMA, based on an LSM specific integrity
policy, or by an integrity context aware LSM.
Signed-off-by: Mimi Zohar <[email protected]>
---
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
new file mode 100644
index 0000000..6434f0d
--- /dev/null
+++ b/Documentation/ABI/testing/ima_policy
@@ -0,0 +1,61 @@
+What: security/ima/policy
+Date: May 2008
+Contact: Mimi Zohar <[email protected]>
+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
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6d4d675..bc49a4a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -44,6 +44,7 @@ parameter is applicable:
FB The frame buffer device is enabled.
HW Appropriate hardware is enabled.
IA-64 IA-64 architecture is enabled.
+ IMA Integrity measurement architecture is enabled.
INTEGRITY Integrity support is enabled.
IOSCHED More than one I/O scheduler is enabled.
IP_PNP IP DHCP, BOOTP, or RARP is enabled.
@@ -895,6 +896,10 @@ and is between 256 and 4096 characters. It is defined in the file
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
+ ima_hash= [IMA] runtime ability to define hash crypto algorithm.
+ Format: { "MD5" | "SHA1" }
+ Default is "SHA1".
+
in2000= [HW,SCSI]
See header of drivers/scsi/in2000.c.
diff --git a/include/linux/ima.h b/include/linux/ima.h
new file mode 100644
index 0000000..b7f0ce7
--- /dev/null
+++ b/include/linux/ima.h
@@ -0,0 +1,46 @@
+/*
+ * ima.h
+ *
+ * Copyright (C) 2008 IBM Corporation
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#ifndef _LINUX_IMA_H
+#define _LINUX_IMA_H
+
+/* IMA LIM Data */
+enum ima_type { IMA_DATA, IMA_METADATA, IMA_TEMPLATE };
+
+struct ima_args_data {
+ const char *filename;
+ struct file *file;
+ struct path *path;
+ struct dentry *dentry;
+ struct inode *inode;
+ enum lim_hooks function;
+ u32 osid;
+ int mask;
+};
+
+struct ima_store_data {
+ char *name;
+ int len;
+ char *data;
+ int violation;
+};
+
+struct ima_data {
+ enum ima_type type;
+ union {
+ struct ima_args_data args;
+ struct ima_store_data template;
+ } data;
+};
+
+void ima_fixup_argsdata(struct ima_args_data *data, struct file *file,
+ struct path *path, int mask, int function);
+#endif
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 7dcb50e..0daee7c 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -22,3 +22,5 @@ config INTEGRITY_AUDIT
at boot. If this option is selected, informational integrity
auditing messages can be enabled with 'integrity_audit=1' on
the kernel command line.
+
+source security/integrity/ima/Kconfig
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index a6e1405..107dafd 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -4,3 +4,4 @@
# Object file lists
obj-$(CONFIG_INTEGRITY) += integrity.o integrity_audit.o
+obj-$(CONFIG_IMA) += ima/
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
new file mode 100644
index 0000000..76b12af
--- /dev/null
+++ b/security/integrity/ima/Kconfig
@@ -0,0 +1,47 @@
+#
+# IBM Integrity Measurement Architecture
+#
+config IMA
+ bool "Integrity Measurement Architecture(IMA)"
+ depends on INTEGRITY
+ depends on ACPI
+ select CRYPTO
+ select CRYPTO_HMAC
+ select CRYPTO_MD5
+ select CRYPTO_SHA1
+ select TCG_TPM
+ select TCG_TIS
+ help
+ The Trusted Computing Group(TCG) runtime Integrity
+ Measurement Architecture(IMA) maintains a list of hash
+ values of executables and other sensitive system files
+ loaded into the run-time of this system. If your system
+ has a TPM chip, then IMA also maintains an aggregate
+ integrity value over this list inside the TPM hardware.
+ These measurements and the aggregate (signed inside the
+ TPM) can be retrieved and presented to remote parties to
+ establish system properties. If unsure, say N.
+
+config IMA_MEASURE_PCR_IDX
+ int "PCR for Aggregate (8 <= Index <= 14)"
+ depends on IMA
+ range 8 14
+ default 10
+ help
+ IMA_MEASURE_PCR_IDX determines the TPM PCR register index
+ that IMA uses to maintain the integrity aggregate of the
+ measurement list. If unsure, use the default 10.
+
+config IMA_BASE_HOOKS
+ bool "IMA base hooks"
+ depends on IMA
+ default n
+ help
+ Enable this option to allow the LSM module to enforce integrity.
+
+config IMA_LSM_RULES
+ bool "Enable LSM measurement policy rules"
+ depends on IMA && (SECURITY_SELINUX || SECURITY_SMACK)
+ default y
+ help
+ Disabling this option will not enforce LSM based policy rules.
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
new file mode 100644
index 0000000..f3aced4
--- /dev/null
+++ b/security/integrity/ima/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for building Trusted Computing Group's(TCG) runtime Integrity
+# Measurement Architecture(IMA).
+#
+
+obj-$(CONFIG_IMA) += ima.o
+
+ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
+ ima_policy.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
new file mode 100644
index 0000000..9a24305
--- /dev/null
+++ b/security/integrity/ima/ima.h
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer <[email protected]>
+ * Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima.h
+ * internal ima definitions
+ */
+
+#ifndef __LINUX_IMA_H
+#define __LINUX_IMA_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/security.h>
+#include <linux/integrity.h>
+#include <linux/hash.h>
+#include <linux/tpm.h>
+
+#define ima_printk(level, format, arg...) \
+ printk(level "ima (%s): " format, __func__, ## arg)
+
+#define ima_error(format, arg...) \
+ ima_printk(KERN_ERR, format, ## arg)
+
+#define ima_info(format, arg...) \
+ ima_printk(KERN_INFO, format, ## arg)
+
+/* digest size for IMA, fits SHA1 or MD5 */
+#define IMA_DIGEST_SIZE 20
+#define IMA_EVENT_NAME_LEN_MAX 255
+
+#define IMA_HASH_BITS 9
+#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
+
+/* set during initialization */
+extern int ima_used_chip;
+extern char *ima_hash;
+
+struct ima_measure_entry {
+ u8 digest[IMA_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
+ char template_name[IMA_EVENT_NAME_LEN_MAX + 1]; /* name + \0 */
+ int template_len;
+ char *template;
+};
+
+struct ima_queue_entry {
+ struct hlist_node hnext; /* place in hash collision list */
+ struct list_head later; /* place in ima_measurements list */
+ struct ima_measure_entry *entry;
+};
+extern struct list_head ima_measurements; /* list of all measurements */
+
+/* declarations */
+extern int ima_template_mode;
+extern const struct template_operations ima_template_ops;
+
+/* Internal IMA function definitions */
+int ima_init(void);
+void ima_cleanup(void);
+int ima_fs_init(void);
+void ima_fs_cleanup(void);
+void ima_create_htable(void);
+int ima_add_measure_entry(struct ima_measure_entry *entry, int violation);
+struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest);
+int ima_calc_hash(struct file *file, struct path *path, char *digest);
+int ima_calc_template_hash(int template_len, char *template, char *digest);
+void ima_add_violation(struct inode *inode, const unsigned char *fname,
+ char *op, char *cause);
+
+enum ima_action { DONT_MEASURE, MEASURE };
+int ima_match_policy(struct inode *inode, enum lim_hooks func, int mask);
+int ima_add_rule(int, char *subj_user, char *subj_role, char *subj_type,
+ char *obj_user, char *obj_role, char *obj_type,
+ char *func, char *mask, char *fsmagic, char *uid);
+void ima_init_policy(void);
+void ima_update_policy(void);
+
+
+/* LIM API function definitions */
+int ima_must_measure(void *d);
+int ima_collect_measurement(void *d);
+int ima_appraise_measurement(void *d);
+void ima_store_measurement(void *d);
+void ima_template_show(struct seq_file *m, void *e,
+ enum integrity_show_type show);
+
+
+/*
+ * used to protect h_table and sha_table
+ */
+extern spinlock_t ima_queue_lock;
+
+struct ima_h_table {
+ atomic_long_t len; /* number of stored measurements in the list */
+ atomic_long_t violations;
+ unsigned int max_htable_size;
+ struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
+ atomic_t queue_len[IMA_MEASURE_HTABLE_SIZE];
+};
+extern struct ima_h_table ima_htable;
+
+static inline unsigned long IMA_HASH_KEY(u8 *digest)
+{
+ return(hash_long(*digest, IMA_HASH_BITS));
+}
+
+/* TPM "Glue" definitions */
+
+#define IMA_TPM ((((u32)TPM_ANY_TYPE)<<16) | (u32)TPM_ANY_NUM)
+static inline void ima_extend(const u8 *hash)
+{
+ if (!ima_used_chip)
+ return;
+
+ if (tpm_pcr_extend(IMA_TPM, CONFIG_IMA_MEASURE_PCR_IDX, hash) != 0)
+ ima_error("Error Communicating to TPM chip\n");
+}
+
+static inline void ima_pcrread(int idx, u8 *pcr, int pcr_size)
+{
+ if (!ima_used_chip)
+ return;
+
+ if (tpm_pcr_read(IMA_TPM, idx, pcr) != 0)
+ ima_error("Error Communicating to TPM chip\n");
+}
+
+struct ima_inode_measure_entry {
+ u8 digest[IMA_DIGEST_SIZE]; /* sha1/md5 measurement hash */
+ char file_name[IMA_EVENT_NAME_LEN_MAX + 1]; /* name + \0 */
+};
+
+/* inode integrity data */
+struct ima_iint_cache {
+ u64 version;
+ ulong flags;
+ u8 hmac[IMA_DIGEST_SIZE];
+ u8 digest[IMA_DIGEST_SIZE];
+ struct mutex mutex;
+};
+#define IMA_IINT_INIT 1
+#define IMA_MUST_MEASURE 2
+#define IMA_MEASURED 4
+
+/* LSM based policy rules require audit */
+#ifdef CONFIG_IMA_LSM_RULES
+
+#define security_filter_rule_init security_audit_rule_init
+#define security_filter_rule_match security_audit_rule_match
+
+#else
+
+static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
+ void **lsmrule)
+{
+ return -EINVAL;
+}
+
+static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
+ void *lsmrule,
+ struct audit_context *actx)
+{
+ return -EINVAL;
+}
+#endif
+#endif
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
new file mode 100644
index 0000000..504c195
--- /dev/null
+++ b/security/integrity/ima/ima_api.c
@@ -0,0 +1,375 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ *
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_api.c
+ * - implements the LIM API
+ */
+#include <linux/module.h>
+#include <linux/integrity.h>
+#include <linux/magic.h>
+#include <linux/writeback.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/audit.h>
+#include <linux/ima.h>
+
+#include "ima.h"
+
+const struct template_operations ima_template_ops = {
+ .must_measure = ima_must_measure,
+ .collect_measurement = ima_collect_measurement,
+ .store_measurement = ima_store_measurement,
+ .display_template = ima_template_show
+};
+
+/**
+ * mode_setup - for compatability with non-template IMA versions
+ * @str: is pointer to a string
+ */
+int ima_template_mode = 1;
+static int __init mode_setup(char *str)
+{
+ if (strncmp(str, "ima", 3) == 0)
+ ima_template_mode = 0;
+ if (strncmp(str, "template", 7) == 0)
+ ima_template_mode = 1;
+ ima_info("template_mode %s \n", ima_template_mode ? "template" : "ima");
+ return 1;
+}
+
+__setup("ima_mode=", mode_setup);
+
+/**
+ * ima_digest_cpy - copy the hash in the IMA template structure to a digest
+ * @template_name: string containing the name of the template (i.e. "ima")
+ * @template: pointer to template structure
+ * @digest: pointer to the digest
+ *
+ * Returns 0 on success, error code otherwise
+ */
+static int ima_digest_cpy(char *template_name, void *template, u8 *digest)
+{
+ int rc, result = 0;
+ struct ima_inode_measure_entry *inode_template =
+ (struct ima_inode_measure_entry *)template;
+
+ rc = strcmp(template_name, "ima");
+ if (rc == 0)
+ memcpy(digest, inode_template->digest,
+ sizeof inode_template->digest);
+ else
+ result = -ENODATA;
+ return result;
+}
+
+/**
+ * ima_store_template_measure - collect and protect template measurements
+ * @template_name: string containing the name of the template (i.e. "ima")
+ * @template_len: length of the template data
+ * @template: actual template data
+ * @violation: invalidate pcr measurement indication
+ * @audit_cause: string containing the audit failure cause
+ *
+ * Calculate the hash of a template entry, add the template entry
+ * to an ordered list of measurement entries maintained inside the kernel,
+ * and also update the aggregate integrity value (maintained inside the
+ * configured TPM PCR) over the hashes of the current list of measurement
+ * entries.
+ *
+ * Applications retrieve the current kernel-held measurement list through
+ * the securityfs entries in /sys/kernel/security/ima. The signed aggregate
+ * TPM PCR (called quote) can be retrieved using a TPM user space library
+ * and is used to validate the measurement list.
+ *
+ * Returns 0 on success, error code otherwise
+ */
+static int ima_store_template_measure(char *template_name, int template_len,
+ char *template, int violation,
+ char **audit_cause)
+{
+ struct ima_measure_entry *entry;
+ u8 digest[IMA_DIGEST_SIZE];
+ struct ima_queue_entry *qe;
+ int count, result = 0;
+
+ memset(digest, 0, IMA_DIGEST_SIZE);
+ if (!violation) {
+ int rc = -ENODATA;
+
+ if (!ima_template_mode)
+ rc = ima_digest_cpy(template_name, template, digest);
+ if (rc < 0)
+ result = ima_calc_template_hash(template_len, template,
+ digest);
+
+ /* hash exists already? */
+ qe = ima_lookup_digest_entry(digest);
+ if (qe) {
+ *audit_cause = "hash_exists";
+ result = -EEXIST;
+ goto out;
+ }
+ }
+
+ /* create new entry and add to measurement list */
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry) {
+ *audit_cause = "ENOMEM";
+ result = -ENOMEM;
+ goto out;
+ }
+
+ entry->template = kzalloc(template_len, GFP_KERNEL);
+ if (!entry->template) {
+ *audit_cause = "ENOMEM";
+ result = -ENOMEM;
+ goto out;
+ }
+ if (!template_name) {
+ *audit_cause = "null_template_name";
+ count = 1;
+ } else {
+ count = strlen(template_name);
+ if (count > IMA_EVENT_NAME_LEN_MAX)
+ count = IMA_EVENT_NAME_LEN_MAX;
+ memcpy(entry->template_name, template_name, count);
+ }
+ entry->template_name[count] = '\0';
+ entry->template_len = template_len;
+ memcpy(entry->template, template, template_len);
+ memcpy(entry->digest, digest, IMA_DIGEST_SIZE);
+
+ result = ima_add_measure_entry(entry, violation);
+ if (result < 0)
+ kfree(entry);
+out:
+ return result;
+}
+
+/**
+ * ima_store_inode_measure - create and store an inode template measurement
+ * @name: ascii file name associated with the measurement hash
+ * @hash_len: length of hash value in bytes (16 for MD5, 20 for SHA1)
+ * @hash: actual hash value pre-calculated
+ *
+ * Returns 0 on success, error code otherwise
+ */
+static int ima_store_inode_measure(struct inode *inode,
+ const unsigned char *name,
+ int hash_len, char *hash, int violation)
+{
+ struct ima_inode_measure_entry measure_entry, *entry = &measure_entry;
+ int result;
+ int namelen;
+ char *op = "add_measure";
+ char *cause = " ";
+
+ memset(entry, 0, sizeof *entry);
+ if (!violation)
+ memcpy(entry->digest, hash, hash_len > IMA_DIGEST_SIZE ?
+ IMA_DIGEST_SIZE : hash_len);
+ if (name) {
+ namelen = strlen(name);
+ memcpy(entry->file_name, name, namelen > IMA_EVENT_NAME_LEN_MAX
+ ? IMA_EVENT_NAME_LEN_MAX : namelen);
+ entry->file_name[namelen] = '\0';
+ }
+ result = ima_store_template_measure("ima", sizeof *entry, (char *)entry,
+ violation, &cause);
+ if (result == -EEXIST)
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
+ name, op, cause, 1);
+ else if (result < 0)
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
+ name, op, cause, 0);
+ return result;
+}
+
+/**
+ * ima_add_violation - add violation to measurement list.
+ * @inode: inode associated with the violation
+ * @fname: name associated with the inode
+ * @op: string pointer to audit operation (i.e. "invalid_pcr", "add_measure")
+ * @cause: string pointer to reason for violation (i.e. "ToMToU")
+ *
+ * Violations are flagged in the measurement list with zero hash values.
+ * By extending the PCR with 0xFF's instead of with zeroes, the PCR
+ * value is invalidated.
+ */
+void ima_add_violation(struct inode *inode, const unsigned char *fname,
+ char *op, char *cause)
+{
+ int result;
+
+ /* can overflow, only indicator */
+ atomic_long_inc(&ima_htable.violations);
+
+ result = ima_store_inode_measure(inode, fname, 0, NULL, 1);
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, fname, op, cause, 0);
+}
+
+/**
+ * skip_measurement - measure only regular files, skip everything else.
+ * @inode: inode being measured
+ * @mask: contains the permission mask
+ *
+ * Quick sanity check to make sure that only regular files opened
+ * for read-only or execute are measured.
+ *
+ * Return 1 to skip measure, 0 to measure
+ */
+static int skip_measurement(struct inode *inode, int mask)
+{
+ if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+ return 1; /* can't measure */
+
+ if (special_file(inode->i_mode) || S_ISLNK(inode->i_mode))
+ return 1; /* don't measure */
+
+ if (S_ISREG(inode->i_mode))
+ return 0; /* measure */
+ return 1; /* don't measure */
+}
+
+/**
+ * ima_must_measure - measure decision based on policy.
+ * @template_data: pointer to struct ima_data containing ima_args_data
+ *
+ * The policy is defined in terms of keypairs:
+ * subj=, obj=, type=, func=, mask=, fsmagic=
+ * subj,obj, and type: are LSM specific.
+ * func: INODE_PERMISSION | BPRM_CHECK | FILE_MMAP
+ * mask: contains the permission mask
+ * fsmagic: hex value
+ *
+ * Return 0 to measure. For matching a DONT_MEASURE policy, no policy,
+ * or other error, return an error code.
+*/
+int ima_must_measure(void *template_data)
+{
+ struct ima_iint_cache *iint;
+ struct ima_data *idata = (struct ima_data *)template_data;
+ struct ima_args_data *data = &idata->data.args;
+ struct inode *inode = data->inode;
+ int must_measure = -EACCES;
+
+ if ((data->mask & MAY_WRITE) || (data->mask & MAY_APPEND))
+ return -EPERM;
+
+ if (skip_measurement(data->inode, data->mask))
+ return -EPERM;
+
+ iint = inode->i_integrity;
+ mutex_lock(&iint->mutex);
+
+ /* short circuit out of here, if iint initialized
+ * and either no measurement required or already measured.
+ */
+ if (iint->flags & IMA_IINT_INIT) {
+ if (!(iint->flags & IMA_MUST_MEASURE)
+ || iint->flags & IMA_MEASURED)
+ must_measure = -EEXIST;
+ else
+ must_measure = 0;
+ } else {
+ int rc;
+
+ rc = ima_match_policy(data->inode, data->function, data->mask);
+ if (rc) {
+ iint->flags = IMA_MUST_MEASURE;
+ must_measure = 0;
+ } else
+ must_measure = -EACCES;
+ iint->flags |= IMA_IINT_INIT;
+ }
+ mutex_unlock(&iint->mutex);
+ return must_measure;
+}
+
+/**
+ * ima_collect_measurement - collect file measurements and store in the inode
+ * @template_data: pointer to struct ima_data containing ima_args_data
+ *
+ * Return 0 on success, error code otherwise
+ */
+int ima_collect_measurement(void *template_data)
+{
+ struct ima_iint_cache *iint;
+ struct ima_data *idata = (struct ima_data *)template_data;
+ struct ima_args_data *data = &idata->data.args;
+ struct dentry *dentry = data->dentry;
+ struct inode *inode = data->inode;
+ int result = 0;
+
+ if (idata->type != IMA_DATA)
+ return -EPERM;
+
+ if (!inode || !dentry)
+ return -EINVAL;
+
+ iint = inode->i_integrity;
+ mutex_lock(&iint->mutex);
+ if (!(iint->flags & IMA_MEASURED)) {
+ memset(iint->digest, 0, IMA_DIGEST_SIZE);
+ result = ima_calc_hash(data->file, data->path, iint->digest);
+ } else
+ result = -EEXIST;
+ mutex_unlock(&iint->mutex);
+ return result;
+}
+
+/**
+ * ima_store_measurement - store file and template measurements
+ * @template_data: pointer to struct ima_data containing ima_args_data,
+ * used to create an IMA template, or a template.
+ *
+ * For file measurements, first create an IMA template and then store it.
+ * For all other types of template measurements, just store it.
+ */
+void ima_store_measurement(void *template_data)
+{
+ struct ima_data *idata = (struct ima_data *)template_data;
+ int result;
+ char *op = "add_template_measure";
+ char *cause = "";
+
+ if (idata->type == IMA_DATA) {
+ struct ima_args_data *data = &idata->data.args;
+ struct ima_iint_cache *iint;
+
+ iint = data->inode->i_integrity;
+ mutex_lock(&iint->mutex);
+ if (iint->flags & IMA_MEASURED) {
+ mutex_unlock(&iint->mutex);
+ return;
+ }
+ result = ima_store_inode_measure(data->inode, data->filename,
+ IMA_DIGEST_SIZE, iint->digest,
+ 0);
+ if (!result || result == -EEXIST) {
+ iint->flags |= IMA_MEASURED;
+ iint->version = data->inode->i_version;
+ }
+ mutex_unlock(&iint->mutex);
+ } else if (idata->type == IMA_TEMPLATE) {
+ struct ima_store_data *template = (struct ima_store_data *)
+ &idata->data.template;
+
+ result = ima_store_template_measure(template->name,
+ template->len,
+ template->data, 0, &cause);
+ if (result == -EEXIST)
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL,
+ template->name, op, cause, 1);
+ else if (result < 0)
+ integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL,
+ template->name, op, cause, 0);
+ }
+}
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
new file mode 100644
index 0000000..c75b22e
--- /dev/null
+++ b/security/integrity/ima/ima_crypto.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <[email protected]>
+ * Kylene Hall <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * File: ima_crypto.c
+ * Calculate a file's or a template's hash.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/crypto.h>
+#include <linux/mm.h>
+#include <linux/mount.h>
+#include <linux/scatterlist.h>
+#include <linux/namei.h>
+#include "ima.h"
+
+/*
+ * Calculate the file hash, using an open file descriptor if available.
+ */
+static int update_file_hash(struct file *f, struct path *path,
+ struct hash_desc *desc)
+{
+ struct file *file = f;
+ struct scatterlist sg[1];
+ loff_t i_size;
+ int rc = 0;
+ char *rbuf;
+ int offset = 0;
+
+ if (!file) {
+ struct dentry *de = dget(path->dentry);
+ struct vfsmount *mnt = mntget(path->mnt);
+ if (!de || !mnt) {
+ rc = -EINVAL;
+ goto err_out;
+ }
+ file = dentry_open(de, mnt, O_RDONLY);
+ if (IS_ERR(file)) {
+ ima_info("%s dentry_open failed\n", de->d_name.name);
+ rc = PTR_ERR(file);
+ file = NULL;
+ }
+err_out:
+ if (!file) {
+ dput(de);
+ mntput(mnt);
+ goto out;
+ }
+ }
+
+ if (!file->f_dentry || !file->f_dentry->d_inode) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!rbuf) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ i_size = i_size_read(file->f_dentry->d_inode);
+ while (offset < i_size) {
+ int rbuf_len;
+
+ rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
+ if (rbuf_len < 0) {
+ rc = rbuf_len;
+ break;
+ }
+ offset += rbuf_len;
+ sg_set_buf(sg, rbuf, rbuf_len);
+
+ rc = crypto_hash_update(desc, sg, rbuf_len);
+ if (rc)
+ break;
+ }
+ kfree(rbuf);
+out:
+ if (file && !f)
+ fput(file); /* clean up dentry_open() */
+ return rc;
+}
+
+/*
+ * Calculate the MD5/SHA1 digest
+ */
+int ima_calc_hash(struct file *file, struct path *path, char *digest)
+{
+ struct hash_desc desc;
+ int rc;
+
+ if (!file && !path)
+ return -EINVAL;
+
+ desc.tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(desc.tfm)) {
+ ima_info("failed to load %s transform: %ld\n",
+ ima_hash, PTR_ERR(desc.tfm));
+ rc = PTR_ERR(desc.tfm);
+ return rc;
+ }
+ desc.flags = 0;
+ rc = crypto_hash_init(&desc);
+ if (rc)
+ goto out;
+
+ rc = update_file_hash(file, path, &desc);
+ if (!rc)
+ rc = crypto_hash_final(&desc, digest);
+out:
+ crypto_free_hash(desc.tfm);
+ return rc;
+}
+
+/*
+ * Calculate the hash of a given template
+ */
+int ima_calc_template_hash(int template_len, char *template, char *digest)
+{
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ int rc;
+
+ desc.tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(desc.tfm)) {
+ ima_info("failed to load %s transform: %ld\n",
+ ima_hash, PTR_ERR(desc.tfm));
+ rc = PTR_ERR(desc.tfm);
+ return rc;
+ }
+ desc.flags = 0;
+ rc = crypto_hash_init(&desc);
+ if (rc)
+ goto out;
+
+ sg_set_buf(sg, template, template_len);
+ rc = crypto_hash_update(&desc, sg, template_len);
+ if (!rc)
+ rc = crypto_hash_final(&desc, digest);
+out:
+ crypto_free_hash(desc.tfm);
+ return rc;
+}
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
new file mode 100644
index 0000000..459b23f
--- /dev/null
+++ b/security/integrity/ima/ima_fs.c
@@ -0,0 +1,478 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Kylene Hall <[email protected]>
+ * Reiner Sailer <[email protected]>
+ * Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_fs.c
+ * implemenents security file system for reporting
+ * current measurement list and IMA statistics
+ */
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/integrity.h>
+
+#include "../integrity.h"
+#include "ima.h"
+
+#define TMPBUFLEN 12
+static ssize_t ima_show_htable_value(char __user *buf, size_t count,
+ loff_t *ppos, atomic_long_t *val)
+{
+ char tmpbuf[TMPBUFLEN];
+ ssize_t len;
+
+ len = scnprintf(tmpbuf, TMPBUFLEN, "%li\n", atomic_long_read(val));
+ return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
+}
+
+static ssize_t ima_show_htable_violations(struct file *filp,
+ char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
+}
+
+static struct file_operations ima_htable_violations_ops = {
+ .read = ima_show_htable_violations
+};
+
+static ssize_t ima_show_measurements_count(struct file *filp,
+ char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
+
+}
+
+static struct file_operations ima_measurements_count_ops = {
+ .read = ima_show_measurements_count
+};
+
+/* returns pointer to hlist_node */
+static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
+{
+ struct list_head *lpos;
+ loff_t l = *pos;
+ /* we need a lock since pos could point beyond last element */
+ rcu_read_lock();
+ __list_for_each_rcu(lpos, &ima_measurements) {
+ if (!l--) {
+ rcu_read_unlock();
+ return lpos;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
+
+static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ /* lock protects when reading beyond last element
+ * against concurrent list-extension */
+ struct list_head *lpos = (struct list_head *)v;
+
+ rcu_read_lock();
+ lpos = rcu_dereference(lpos->next);
+ rcu_read_unlock();
+ (*pos)++;
+
+ return (lpos == &ima_measurements) ? NULL : lpos;
+}
+
+static void ima_measurements_stop(struct seq_file *m, void *v)
+{
+}
+
+/* print format:
+ * 32bit-le=pcr#
+ * char[20]=template digest
+ * 32bit-le=template size
+ * 32bit-le=template name size
+ * eventdata[n] = template name
+ *
+ */
+static int ima_measurements_show(struct seq_file *m, void *v)
+{
+ /* the list never shrinks, so we don't need a lock here */
+ struct list_head *lpos = v;
+ struct ima_queue_entry *qe;
+ struct ima_measure_entry *e;
+ struct ima_inode_measure_entry *entry;
+ struct template_list_entry *template_entry;
+ int templatename_len;
+ int i;
+ u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+ char data[4];
+
+ /* get entry */
+ qe = list_entry(lpos, struct ima_queue_entry, later);
+ e = qe->entry;
+ if (e == NULL)
+ return -1;
+
+ /*
+ * 1st: PCRIndex
+ * PCR used is always the same (config option) in
+ * little-endian format
+ */
+ memcpy(data, &pcr, 4);
+ for (i = 0; i < 4; i++)
+ seq_putc(m, data[i]);
+
+ /* 2nd: template digest */
+ for (i = 0; i < 20; i++)
+ seq_putc(m, e->digest[i]);
+
+ /* 3rd: template name size */
+ templatename_len = strlen(e->template_name);
+ if (templatename_len > IMA_EVENT_NAME_LEN_MAX)
+ templatename_len = IMA_EVENT_NAME_LEN_MAX;
+
+ memcpy(data, &templatename_len, 4);
+ for (i = 0; i < 4; i++)
+ seq_putc(m, data[i]);
+
+ /* 4th: template name */
+ for (i = 0; i < templatename_len; i++)
+ seq_putc(m, e->template_name[i]);
+
+ /* 5th: template dependent */
+ entry = (struct ima_inode_measure_entry *)e->template;
+ if (integrity_find_template(e->template_name, &template_entry) == 0) {
+ if (template_entry) {
+ const struct template_operations *ops;
+
+ ops = template_entry->template_ops;
+ ops->display_template(m, entry, INTEGRITY_SHOW_BINARY);
+ }
+ } else
+ seq_printf(m, " \n");
+ return 0;
+}
+
+static struct seq_operations ima_measurments_seqops = {
+ .start = ima_measurements_start,
+ .next = ima_measurements_next,
+ .stop = ima_measurements_stop,
+ .show = ima_measurements_show
+};
+
+static int ima_measurements_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &ima_measurments_seqops);
+}
+
+static struct file_operations ima_measurements_ops = {
+ .open = ima_measurements_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+void ima_template_show(struct seq_file *m, void *e,
+ enum integrity_show_type show)
+{
+ struct ima_inode_measure_entry *entry =
+ (struct ima_inode_measure_entry *)e;
+ int filename_len;
+ char data[4];
+ int i;
+
+ /* Display file digest */
+ if (ima_template_mode)
+ for (i = 0; i < 20; i++) {
+ switch (show) {
+ case INTEGRITY_SHOW_ASCII:
+ seq_printf(m, "%02x", entry->digest[i]);
+ break;
+ case INTEGRITY_SHOW_BINARY:
+ seq_putc(m, entry->digest[i]);
+ default:
+ break;
+ }
+ }
+
+ switch (show) {
+ case INTEGRITY_SHOW_ASCII:
+ seq_printf(m, " %s\n", entry->file_name);
+ break;
+ case INTEGRITY_SHOW_BINARY:
+ filename_len = strlen(entry->file_name);
+ if (filename_len > IMA_EVENT_NAME_LEN_MAX)
+ filename_len = IMA_EVENT_NAME_LEN_MAX;
+
+ memcpy(data, &filename_len, 4);
+ for (i = 0; i < 4; i++)
+ seq_putc(m, data[i]);
+ for (i = 0; i < filename_len; i++)
+ seq_putc(m, entry->file_name[i]);
+ default:
+ break;
+ }
+}
+
+/* print in ascii */
+static int ima_ascii_measurements_show(struct seq_file *m, void *v)
+{
+ /* the list never shrinks, so we don't need a lock here */
+ struct list_head *lpos = v;
+ struct ima_queue_entry *qe;
+ struct ima_measure_entry *e;
+ struct ima_inode_measure_entry *entry;
+ struct template_list_entry *template_entry;
+ int i;
+
+ /* get entry */
+ qe = list_entry(lpos, struct ima_queue_entry, later);
+ e = qe->entry;
+ if (e == NULL)
+ return -1;
+
+ /* 1st: PCR used (config option) */
+ seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
+
+ /* 2nd: SHA1 template hash */
+ for (i = 0; i < 20; i++)
+ seq_printf(m, "%02x", e->digest[i]);
+
+ /* 3th: template name */
+ seq_printf(m, " %s ", e->template_name);
+
+ /* 4th: filename <= max + \'0' delimiter */
+ entry = (struct ima_inode_measure_entry *)e->template;
+ if (integrity_find_template(e->template_name, &template_entry) == 0) {
+ if (template_entry) {
+ const struct template_operations *ops;
+
+ ops = template_entry->template_ops;
+ ops->display_template(m, entry, INTEGRITY_SHOW_ASCII);
+ }
+ } else
+ seq_printf(m, " \n");
+
+ return 0;
+}
+
+static struct seq_operations ima_ascii_measurements_seqops = {
+ .start = ima_measurements_start,
+ .next = ima_measurements_next,
+ .stop = ima_measurements_stop,
+ .show = ima_ascii_measurements_show
+};
+
+static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &ima_ascii_measurements_seqops);
+}
+
+static struct file_operations ima_ascii_measurements_ops = {
+ .open = ima_ascii_measurements_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static char *get_tag(char *bufStart, char *bufEnd, char delimiter, int *taglen)
+{
+ char *bufp = bufStart;
+ char *tag;
+
+ /* Get start of tag */
+ while (bufp < bufEnd) {
+ if (*bufp == ' ') /* skip blanks */
+ while ((*bufp == ' ') && (bufp++ < bufEnd)) ;
+ else if (*bufp == '#') { /* skip comment */
+ while ((*bufp != '\n') && (bufp++ < bufEnd)) ;
+ bufp++;
+ } else if (*bufp == '\n') /* skip newline */
+ bufp++;
+ else if (*bufp == '\t') /* skip tabs */
+ bufp++;
+ else
+ break;
+ }
+ if (bufp < bufEnd)
+ tag = bufp;
+ else
+ return NULL;
+
+ /* Get tag */
+ *taglen = 0;
+ while ((bufp < bufEnd) && (*taglen == 0)) {
+ if ((*bufp == delimiter) || (*bufp == '\n')) {
+ *taglen = bufp - tag;
+ *bufp = '\0';
+ }
+ bufp++;
+ }
+ if (*taglen == 0) /* Didn't find end delimiter */
+ tag = NULL;
+ return tag;
+}
+
+static ssize_t ima_write_policy(struct file *file, const char __user *buf,
+ size_t buflen, loff_t *ppos)
+{
+ size_t rc = 0, datalen;
+ int action = 0;
+ char *data, *datap, *dataend;
+ char *subj_user = NULL, *subj_role = NULL, *subj_type = NULL;
+ char *obj_user = NULL, *obj_role = NULL, *obj_type = NULL;
+ char *func = NULL, *mask = NULL, *fsmagic = NULL, *uid = NULL;
+ int err = 0;
+ char *tag;
+ int taglen, i;
+
+ datalen = buflen > 4095 ? 4095 : buflen;
+ data = kmalloc(datalen + 1, GFP_KERNEL);
+ if (!data)
+ rc = -ENOMEM;
+
+ if (copy_from_user(data, buf, datalen)) {
+ kfree(data);
+ return -EFAULT;
+ }
+
+ rc = datalen;
+ *(data + datalen) = ' ';
+
+ datap = data;
+ dataend = data + datalen;
+
+ if (strncmp(datap, "measure", 7) == 0) {
+ datap += 8;
+ action = 1;
+ } else if (strncmp(datap, "dont_measure", 12) == 0)
+ datap += 13;
+ else /* bad format */
+ goto out;
+
+ for (i = 0; i < 6; i++) {
+ tag = get_tag(datap, dataend, ' ', &taglen);
+ if (!tag)
+ break;
+ if (strncmp(tag, "obj_user=", 9) == 0)
+ obj_user = tag + 9;
+ else if (strncmp(tag, "obj_role=", 9) == 0)
+ obj_role = tag + 9;
+ else if (strncmp(tag, "obj_type=", 9) == 0)
+ obj_type = tag + 9;
+ else if (strncmp(tag, "subj_user=", 10) == 0)
+ subj_user = tag + 10;
+ else if (strncmp(tag, "subj_role=", 10) == 0)
+ subj_role = tag + 10;
+ else if (strncmp(tag, "subj_type=", 10) == 0)
+ subj_type = tag + 10;
+ else if (strncmp(tag, "func=", 5) == 0)
+ func = tag + 5;
+ else if (strncmp(tag, "mask=", 5) == 0)
+ mask = tag + 5;
+ else if (strncmp(tag, "fsmagic=", 8) == 0)
+ fsmagic = tag + 8;
+ else if (strncmp(tag, "uid=", 4) == 0)
+ uid = tag + 4;
+ else { /* bad format */
+ err = 1;
+ break;
+ }
+ datap += taglen + 1;
+ }
+
+ if (!err)
+ ima_add_rule(action, subj_user, subj_role, subj_type,
+ obj_user, obj_role, obj_type,
+ func, mask, fsmagic, uid);
+out:
+ if (!data)
+ kfree(data);
+ return rc;
+}
+
+static struct dentry *ima_dir;
+static struct dentry *binary_runtime_measurements;
+static struct dentry *ascii_runtime_measurements;
+static struct dentry *runtime_measurements_count;
+static struct dentry *violations;
+static struct dentry *ima_policy;
+
+static int ima_release_policy(struct inode *inode, struct file *file)
+{
+ ima_update_policy();
+ securityfs_remove(ima_policy);
+ ima_policy = NULL;
+ return 0;
+}
+
+static struct file_operations ima_measure_policy_ops = {
+ .write = ima_write_policy,
+ .release = ima_release_policy
+};
+
+int ima_fs_init(void)
+{
+ ima_dir = securityfs_create_dir("ima", NULL);
+ if (!ima_dir || IS_ERR(ima_dir))
+ return -1;
+
+ binary_runtime_measurements =
+ securityfs_create_file("binary_runtime_measurements",
+ S_IRUSR | S_IRGRP, ima_dir, NULL,
+ &ima_measurements_ops);
+ if (!binary_runtime_measurements || IS_ERR(binary_runtime_measurements))
+ goto out;
+
+ ascii_runtime_measurements =
+ securityfs_create_file("ascii_runtime_measurements",
+ S_IRUSR | S_IRGRP, ima_dir, NULL,
+ &ima_ascii_measurements_ops);
+ if (!ascii_runtime_measurements || IS_ERR(ascii_runtime_measurements))
+ goto out;
+
+ runtime_measurements_count =
+ securityfs_create_file("runtime_measurements_count",
+ S_IRUSR | S_IRGRP, ima_dir, NULL,
+ &ima_measurements_count_ops);
+ if (!runtime_measurements_count || IS_ERR(runtime_measurements_count))
+ goto out;
+
+ violations =
+ securityfs_create_file("violations", S_IRUSR | S_IRGRP,
+ ima_dir, NULL, &ima_htable_violations_ops);
+ if (!violations || IS_ERR(violations))
+ goto out;
+
+ ima_policy = securityfs_create_file("policy",
+ S_IRUSR | S_IRGRP | S_IWUSR,
+ ima_dir, NULL,
+ &ima_measure_policy_ops);
+ ima_init_policy();
+ return 0;
+
+out:
+ securityfs_remove(runtime_measurements_count);
+ securityfs_remove(ascii_runtime_measurements);
+ securityfs_remove(binary_runtime_measurements);
+ securityfs_remove(ima_dir);
+ securityfs_remove(ima_policy);
+ return -1;
+}
+
+void __exit ima_fs_cleanup(void)
+{
+ securityfs_remove(violations);
+ securityfs_remove(runtime_measurements_count);
+ securityfs_remove(ascii_runtime_measurements);
+ securityfs_remove(binary_runtime_measurements);
+ securityfs_remove(ima_dir);
+ securityfs_remove(ima_policy);
+}
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
new file mode 100644
index 0000000..c3c87de
--- /dev/null
+++ b/security/integrity/ima/ima_init.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer <[email protected]>
+ * Leendert van Doorn <[email protected]>
+ * Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_init.c
+ * initialization and cleanup functions
+ */
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include "ima.h"
+
+/* name for boot aggregate entry */
+static char *boot_aggregate_name = "boot_aggregate";
+static const char version[] = "v7.6 02/27/2007";
+
+int ima_used_chip;
+
+static void ima_add_boot_aggregate(void)
+{
+ /* cumulative sha1 over tpm registers 0-7 */
+ struct ima_measure_entry *entry;
+ size_t count;
+ int err;
+
+ /* create new entry for boot aggregate */
+ entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+ if (entry == NULL) {
+ ima_add_violation(NULL, boot_aggregate_name,
+ "add_measure", "ENOMEM");
+ return;
+ }
+ count = strlen(boot_aggregate_name);
+ if (count > IMA_EVENT_NAME_LEN_MAX)
+ count = IMA_EVENT_NAME_LEN_MAX;
+ memcpy(entry->template_name, boot_aggregate_name, count);
+ entry->template_name[count] = '\0';
+ if (ima_used_chip) {
+ int i;
+ u8 pcr_i[20];
+ struct hash_desc desc;
+ struct crypto_hash *tfm;
+ struct scatterlist sg;
+
+ tfm = crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC);
+ if (!tfm || IS_ERR(tfm)) {
+ kfree(entry);
+ ima_error("error initializing digest.\n");
+ return;
+ }
+ desc.tfm = tfm;
+ desc.flags = 0;
+ crypto_hash_init(&desc);
+
+ for (i = 0; i < 8; i++) {
+ ima_pcrread(i, pcr_i, sizeof(pcr_i));
+ /* now accumulate with current aggregate */
+ sg_init_one(&sg, (u8 *) pcr_i, 20);
+ crypto_hash_update(&desc, &sg, 20);
+ }
+ crypto_hash_final(&desc, entry->digest);
+ crypto_free_hash(tfm);
+ } else
+ memset(entry->digest, 0xff, 20);
+
+ /* now add measurement; if TPM bypassed, we have a ff..ff entry */
+ err = ima_add_measure_entry(entry, 0);
+ if (err < 0) {
+ kfree(entry);
+ ima_add_violation(NULL, boot_aggregate_name,
+ "add_measure", " ");
+ }
+}
+
+int ima_init(void)
+{
+ int rc;
+
+ ima_used_chip = 0;
+ rc = tpm_pcr_read(IMA_TPM, 0, NULL);
+ if (rc == 0)
+ ima_used_chip = 1;
+
+ if (!ima_used_chip)
+ ima_info("No TPM chip found(rc = %d), activating TPM-bypass!\n",
+ rc);
+
+ ima_create_htable(); /* for measurements */
+ ima_add_boot_aggregate(); /* boot aggregate must be first entry */
+
+ return ima_fs_init();
+}
+
+void __exit ima_cleanup(void)
+{
+ ima_fs_cleanup();
+}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
new file mode 100644
index 0000000..2b90df9
--- /dev/null
+++ b/security/integrity/ima/ima_main.c
@@ -0,0 +1,353 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer <[email protected]>
+ * Serge Hallyn <[email protected]>
+ * Kylene Hall <[email protected]>
+ * Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_main.c
+ * implements the IMA LIM hooks
+ */
+#include <linux/module.h>
+#include <linux/integrity.h>
+#include <linux/magic.h>
+#include <linux/writeback.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/audit.h>
+#include <linux/ima.h>
+#include <linux/mman.h>
+#include <linux/namei.h>
+
+#include "ima.h"
+
+static bool ima_initialized = false;
+char *ima_hash = "sha1";
+static int __init hash_setup(char *str)
+{
+ char *op = "setup";
+ char *hash = "sha1";
+
+ if (strncmp(str, "md5", 3) == 0) {
+ op = "setup";
+ hash = "md5";
+ ima_hash = str;
+ } else if (strncmp(str, "sha1", 4) != 0) {
+ op = "hash_setup";
+ hash = "invalid_hash_type";
+ }
+ integrity_audit_msg(AUDIT_INTEGRITY_HASH, NULL, NULL, op, hash, 0);
+ return 1;
+}
+
+__setup("ima_hash=", hash_setup);
+
+/* For use when the LSM module makes LIM API calls */
+#ifdef CONFIG_IMA_BASE_HOOKS
+static int ima_base_hooks = 1;
+#else
+static int ima_base_hooks;
+#endif
+
+/*
+ * Setup the data structure used for the IMA LIM API calls.
+ */
+void ima_fixup_argsdata(struct ima_args_data *data, struct file *file,
+ struct path *path, int mask, int function)
+{
+ struct dentry *dentry = NULL;
+
+ data->file = file;
+ data->path = path;
+ data->mask = mask;
+ data->function = function;
+
+ if (file && file->f_dentry) {
+ data->dentry = dentry = file->f_dentry;
+ }
+ if (path && path->dentry) {
+ if (!dentry)
+ data->dentry = dentry = path->dentry;
+ }
+ if (dentry && dentry->d_inode) {
+ data->inode = dentry->d_inode;
+ }
+
+ return;
+}
+
+/**
+ * ima_file_free - called on close
+ * @file: pointer to file being closed
+ *
+ * Flag files that changed, based on i_version.
+ */
+static void ima_file_free(struct file *file)
+{
+ struct inode *inode = NULL;
+ struct ima_iint_cache *iint;
+
+ if (!file->f_dentry) /* can be NULL */
+ return;
+
+ inode = file->f_dentry->d_inode;
+ if (S_ISDIR(inode->i_mode))
+ return;
+ if ((file->f_mode & FMODE_WRITE) &&
+ (atomic_read(&inode->i_writecount) == 1)) {
+ iint = inode->i_integrity;
+ mutex_lock(&iint->mutex);
+ if (iint->version != inode->i_version)
+ iint->flags &= ~IMA_MEASURED;
+ mutex_unlock(&iint->mutex);
+ }
+}
+
+/**
+ * ima_alloc_integrity - allocate and attach an integrity structure
+ * @inode: the inode structure
+ *
+ * Returns 0 on success, -ENOMEM on failure
+ */
+static int ima_inode_alloc_integrity(struct inode *inode)
+{
+ struct ima_iint_cache *iint;
+
+ iint = kzalloc(sizeof(*iint), GFP_KERNEL);
+ if (!iint)
+ return -ENOMEM;
+
+ mutex_init(&iint->mutex);
+ inode->i_integrity = iint;
+ iint->version = inode->i_version;
+ return 0;
+}
+
+/**
+ * ima_inode_free_integrity - free the integrity structure
+ * @inode: the inode structure
+ */
+static void ima_inode_free_integrity(struct inode *inode)
+{
+ struct ima_iint_cache *iint = inode->i_integrity;
+
+ if (iint) {
+ inode->i_integrity = NULL;
+ kfree(iint);
+ }
+}
+
+/**
+ * ima_nameidata_check_integrity - based on policy, collect/store measurement.
+ * @nameidata: contains a pointer to the nameidata to be measured
+ * @mask: contains MAY_READ, MAY_WRITE, MAY_APPEND or MAY_EXECUTE
+ *
+ * Measure the inode being open for read, based on the ima_must_measure()
+ * policy decision.
+ *
+ * Invalidate the PCR:
+ * - Opening a file for write when already open for read,
+ * results in a time of measure, time of use (ToMToU) error.
+ * - Opening a file for read when already open for write,
+ * could result in a file measurement error.
+ *
+ * Return 0 on success, an error code on failure.
+ * (Based on the results of appraise_measurement().)
+ */
+static int ima_nameidata_check_integrity(struct nameidata *nd, int mask)
+{
+ struct ima_data idata;
+ struct ima_args_data *data = &idata.data.args;
+ struct dentry *dentry;
+ struct inode *inode;
+
+ if (!ima_initialized)
+ return 0;
+
+ memset(&idata, 0, sizeof idata);
+ ima_fixup_argsdata(data, NULL, &nd->path, mask, INODE_PERMISSION);
+ inode = data->inode;
+
+ /* The file name is only a hint. */
+ dentry = nd->path.dentry;
+ data->filename = (!dentry->d_name.name) ? (char *)dentry->d_iname :
+ (char *)dentry->d_name.name;
+
+ /* Invalidate PCR, if a measured file is already open for read */
+ if ((mask == MAY_WRITE) || (mask == MAY_APPEND)) {
+ int mask_sav = data->mask;
+ int rc;
+
+ data->mask = MAY_READ;
+ rc = ima_must_measure(&idata);
+ if (!rc) {
+ if (atomic_read(&(data->dentry->d_count)) - 1 >
+ atomic_read(&(inode->i_writecount)))
+ ima_add_violation(inode, data->filename,
+ "invalid_pcr", "ToMToU");
+ }
+ data->mask = mask_sav;
+ goto out;
+ }
+
+ /* measure executables later */
+ if (mask & MAY_READ) {
+ int rc;
+
+ rc = ima_must_measure(&idata);
+ if (!rc) {
+ /* Invalidate PCR, if a measured file is
+ * already open for write.
+ */
+ if (atomic_read(&(inode->i_writecount)) > 0)
+ ima_add_violation(inode, data->filename,
+ "invalid_pcr",
+ "open_writers");
+
+ idata.type = IMA_DATA;
+ rc = ima_collect_measurement(&idata);
+ if (!rc)
+ ima_store_measurement(&idata);
+ }
+ }
+out:
+ return 0;
+}
+
+/**
+ * ima_file_mmap - based on policy, collect/store measurement.
+ * @file: pointer to the file to be measured
+ * @prot contains the protection that will be applied by the kernel.
+ *
+ * Measure files being mmapped executable based on the ima_must_measure()
+ * policy decision.
+ *
+ * Return 0 on success, an error code on failure.
+ * (Based on the results of appraise_measurement().)
+ */
+static int ima_file_mmap(struct file *file, unsigned long prot)
+{
+ struct ima_data idata;
+ struct ima_args_data *data = &idata.data.args;
+ int rc = 0;
+
+ if (!ima_initialized)
+ return 0;
+ if (!file || !file->f_dentry)
+ return rc;
+ if (!(prot & VM_EXEC))
+ return rc;
+
+ ima_fixup_argsdata(data, file, NULL, MAY_EXEC, FILE_MMAP);
+ data->filename = (!file->f_dentry->d_name.name) ?
+ (char *)file->f_dentry->d_iname :
+ (char *)file->f_dentry->d_name.name;
+
+ rc = ima_must_measure(&idata);
+ if (!rc) {
+ idata.type = IMA_DATA;
+ rc = ima_collect_measurement(&idata);
+ if (!rc)
+ ima_store_measurement(&idata);
+ }
+ return 0;
+}
+
+/**
+ * ima_bprm_check_integrity - based on policy, collect/store measurement.
+ * @bprm: contains the linux_binprm structure
+ *
+ * The OS protects against an executable file, already open for write,
+ * from being executed in deny_write_access() and an executable file,
+ * already open for execute, from being modified in get_write_access().
+ * So we can be certain that what we verify and measure here is actually
+ * what is being executed.
+ *
+ * Return 0 on success, an error code on failure.
+ * (Based on the results of appraise_measurement().)
+ */
+static int ima_bprm_check_integrity(struct linux_binprm *bprm)
+{
+ struct ima_data idata;
+ struct ima_args_data *data = &idata.data.args;
+ int rc = 0;
+
+ if (!ima_initialized)
+ return 0;
+ ima_fixup_argsdata(data, bprm->file, NULL, MAY_EXEC, BPRM_CHECK);
+ data->filename = bprm->filename;
+
+ rc = ima_must_measure(&idata);
+ if (!rc) {
+ idata.type = IMA_DATA;
+ rc = ima_collect_measurement(&idata);
+ if (!rc)
+ ima_store_measurement(&idata);
+ }
+ return 0;
+}
+
+static const struct integrity_operations ima_integrity_ops = {
+ .bprm_check_integrity = ima_bprm_check_integrity,
+ .nameidata_check_integrity = ima_nameidata_check_integrity,
+ .inode_alloc_integrity = ima_inode_alloc_integrity,
+ .inode_free_integrity = ima_inode_free_integrity,
+ .file_free_integrity = ima_file_free,
+ .file_mmap = ima_file_mmap,
+};
+
+static const struct integrity_operations ima_base_ops = {
+ .inode_alloc_integrity = ima_inode_alloc_integrity,
+ .inode_free_integrity = ima_inode_free_integrity,
+ .file_free_integrity = ima_file_free,
+};
+
+/* Register the integrity ops early so that i_integrity is
+ * allocated at inode initialization.
+ */
+static int __init init_ops(void)
+{
+ int error;
+
+ if (ima_base_hooks)
+ error = register_integrity(&ima_base_ops);
+ else
+ error = register_integrity(&ima_integrity_ops);
+ return error;
+}
+
+/* After the TPM is available, start IMA
+ */
+static int __init init_ima(void)
+{
+ int error;
+
+ error = ima_init();
+ if (error)
+ goto out;
+ ima_initialized = true;
+ integrity_register_template("ima", &ima_template_ops);
+out:
+ return error;
+}
+
+static void __exit cleanup_ima(void)
+{
+ integrity_unregister_template("ima");
+ unregister_integrity(&ima_integrity_ops);
+ ima_cleanup();
+}
+
+security_initcall(init_ops); /* Register the integrity ops early */
+late_initcall(init_ima); /* Start IMA after the TPM is available */
+module_exit(cleanup_ima);
+
+MODULE_DESCRIPTION("Integrity Measurement Architecture");
+MODULE_LICENSE("GPL");
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
new file mode 100644
index 0000000..2e95c35
--- /dev/null
+++ b/security/integrity/ima/ima_policy.c
@@ -0,0 +1,334 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * ima_policy.c
+ * - initialize default measure policy rules
+ - load a policy ruleset
+ *
+ */
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/audit.h>
+#include <linux/security.h>
+#include <linux/integrity.h>
+#include <linux/magic.h>
+
+#include "ima.h"
+
+#define MAX_LSM_RULES 6
+enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
+ LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
+};
+
+#define audit_type(type) AUDIT_ ##type
+#define lsm_type(type) LSM_ ##type
+
+struct ima_measure_rule_entry {
+ struct list_head list;
+ int action;
+ struct {
+ void *rule;
+ int type; /* audit type */
+ } lsm_field[MAX_LSM_RULES];
+ uint flags;
+ enum lim_hooks func;
+ int mask;
+ ulong fsmagic;
+ uid_t uid;
+};
+
+/* flags definitions */
+#define IMA_FUNC 0x0001
+#define IMA_MASK 0x0002
+#define IMA_FSMAGIC 0x0004
+#define IMA_UID 0x0008
+
+/* Without LSM specific knowledge, default policy can only be
+ * written in terms of .action, .func, .mask, .fsmagic, and .uid
+ */
+static struct ima_measure_rule_entry default_rules[] = {
+ {.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,
+ .flags = IMA_FSMAGIC},
+ {.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,
+ .flags = IMA_FSMAGIC},
+ {.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
+ .flags = IMA_FUNC | IMA_MASK},
+ {.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
+ .flags = IMA_FUNC | IMA_MASK},
+ {.action = MEASURE,.func = INODE_PERMISSION,.mask = MAY_READ,.uid = 0,
+ .flags = IMA_FUNC | IMA_MASK | IMA_UID}
+};
+
+static struct list_head measure_default_rules;
+static struct list_head measure_policy_rules;
+static struct list_head *ima_measure;
+
+static DEFINE_MUTEX(ima_measure_mutex);
+
+/**
+ * ima_match_rules - determine whether an inode matches the measure rule.
+ * @rule: a pointer to a rule
+ * @inode: a pointer to an inode
+ * @func: LIM hook identifier
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ *
+ * Returns true on rule match, false on failure.
+ */
+static bool ima_match_rules(struct ima_measure_rule_entry *rule,
+ struct inode *inode, enum lim_hooks func, int mask)
+{
+ struct task_struct *tsk = current;
+ int i;
+
+ if ((rule->flags & IMA_FUNC) && rule->func != func)
+ return false;
+ if ((rule->flags & IMA_MASK) && rule->mask != mask)
+ return false;
+ if ((rule->flags & IMA_FSMAGIC)
+ && rule->fsmagic != inode->i_sb->s_magic)
+ return false;
+ if ((rule->flags & IMA_UID) && rule->uid != tsk->uid)
+ return false;
+ for (i = 0; i < MAX_LSM_RULES; i++) {
+ int rc;
+ u32 osid, sid;
+
+ if (!rule->lsm_field[i].rule)
+ continue;
+
+ switch (i) {
+ case LSM_OBJ_USER:
+ case LSM_OBJ_ROLE:
+ case LSM_OBJ_TYPE:
+ security_inode_getsecid(inode, &osid);
+ rc = security_filter_rule_match(osid,
+ rule->lsm_field[i].type,
+ AUDIT_EQUAL,
+ rule->lsm_field[i].rule,
+ NULL);
+ break;
+ case LSM_SUBJ_USER:
+ case LSM_SUBJ_ROLE:
+ case LSM_SUBJ_TYPE:
+ security_task_getsecid(tsk, &sid);
+ rc = security_filter_rule_match(sid,
+ rule->lsm_field[i].type,
+ AUDIT_EQUAL,
+ rule->lsm_field[i].rule,
+ NULL);
+ default:
+ break;
+ }
+ if (!rc)
+ return false;
+ }
+ return true;
+}
+
+/**
+ * ima_match_policy - decision based on LSM and other conditions
+ * @inode: pointer to an inode
+ * @func: IMA hook identifier
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ *
+ * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
+ * conditions. Returns rule action on rule match, 0 on failure.
+ */
+int ima_match_policy(struct inode *inode, enum lim_hooks func, int mask)
+{
+ struct ima_measure_rule_entry *entry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(entry, ima_measure, list) {
+ bool rc;
+
+ rc = ima_match_rules(entry, inode, func, mask);
+ if (rc) {
+ rcu_read_unlock();
+ return entry->action;
+ }
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+/**
+ * ima_init_policy - initialize the default and policy measure rules.
+ */
+void ima_init_policy(void)
+{
+ int i;
+
+ INIT_LIST_HEAD(&measure_default_rules);
+ for (i = 0; i < ARRAY_SIZE(default_rules); i++)
+ list_add_tail(&default_rules[i].list, &measure_default_rules);
+ ima_measure = &measure_default_rules;
+
+ INIT_LIST_HEAD(&measure_policy_rules);
+}
+
+/**
+ * ima_update_policy - update default_rules with new measure rules
+ *
+ * Wait to update the default rules with a complete new set of measure rules.
+ */
+void ima_update_policy(void)
+{
+ char *op = "policy_update";
+ char *cause = "already exists";
+ int result = 1;
+
+ if (ima_measure == &measure_default_rules) {
+ ima_measure = &measure_policy_rules;
+ cause = "complete";
+ result = 0;
+ }
+ integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
+ NULL, op, cause, result);
+}
+
+/**
+ * ima_add_rule - add ima measure rules
+ * @action: integer 1 indicating MEASURE, 0 indicating DONT_MEASURE
+ * @subj_user: pointer to an LSM subject's user value
+ * @subj_role: pointer to an LSM subject's role value
+ * @subj_type: pointer to an LSM subject's type value
+ * @obj_user: pointer to an LSM object's user value
+ * @obj_role: pointer to an LSM object's role value
+ * @obj_type: pointer to an LSM object's type value
+ * @func: LIM hook identifier
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ * @fsmagic: fs magic hex value string
+ * @uid: uid value string
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int ima_add_rule(int action,
+ char *subj_user, char *subj_role, char *subj_type,
+ char *obj_user, char *obj_role, char *obj_type,
+ char *func, char *mask, char *fsmagic, char *uid)
+{
+ struct ima_measure_rule_entry *entry;
+ int i, result = 0;
+
+ /* Prevent installed policy from changing */
+ if (ima_measure != &measure_default_rules) {
+ integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
+ NULL, "policy_update", "already exists", 0);
+ return -EACCES;
+ }
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ INIT_LIST_HEAD(&entry->list);
+ if (action < 0 || action > 1)
+ result = -EINVAL;
+ else
+ entry->action = action;
+
+ if (!result && subj_user) {
+ i = lsm_type(SUBJ_USER);
+ entry->lsm_field[i].type = audit_type(SUBJ_USER);
+ result = security_filter_rule_init(entry->lsm_field[i].type,
+ AUDIT_EQUAL, subj_user,
+ &entry->lsm_field[i].rule);
+ }
+ if (!result && subj_role) {
+ i = lsm_type(SUBJ_ROLE);
+ entry->lsm_field[i].type = audit_type(SUBJ_ROLE);
+ result = security_filter_rule_init(entry->lsm_field[i].type,
+ AUDIT_EQUAL, subj_role,
+ &entry->lsm_field[i].rule);
+ }
+ if (!result && subj_type) {
+ i = lsm_type(SUBJ_TYPE);
+ entry->lsm_field[i].type = audit_type(SUBJ_TYPE);
+ result = security_filter_rule_init(entry->lsm_field[i].type,
+ AUDIT_EQUAL, subj_type,
+ &entry->lsm_field[i].rule);
+ }
+ if (!result && obj_user) {
+ i = lsm_type(OBJ_USER);
+ entry->lsm_field[i].type = audit_type(OBJ_USER);
+ result = security_filter_rule_init(entry->lsm_field[i].type,
+ AUDIT_EQUAL, obj_user,
+ &entry->lsm_field[i].rule);
+ }
+ if (!result && obj_role) {
+ i = lsm_type(OBJ_ROLE);
+ entry->lsm_field[i].type = audit_type(OBJ_ROLE);
+ result = security_filter_rule_init(entry->lsm_field[i].type,
+ AUDIT_EQUAL, obj_role,
+ &entry->lsm_field[i].rule);
+ }
+ if (!result && obj_type) {
+ i = lsm_type(OBJ_TYPE);
+ entry->lsm_field[i].type = audit_type(OBJ_TYPE);
+ result = security_filter_rule_init(entry->lsm_field[i].type,
+ AUDIT_EQUAL, obj_type,
+ &entry->lsm_field[i].rule);
+ }
+ if (!result && func) {
+ if (strcmp(func, "INODE_PERMISSION") == 0)
+ entry->func = INODE_PERMISSION;
+ else if (strcmp(func, "FILE_MMAP") == 0)
+ entry->func = FILE_MMAP;
+ else if (strcmp(func, "BPRM_CHECK") == 0)
+ entry->func = BPRM_CHECK;
+ else
+ result = -EINVAL;
+ if (!result)
+ entry->flags |= IMA_FUNC;
+ }
+ if (!result && mask) {
+ if (strcmp(mask, "MAY_EXEC") == 0)
+ entry->mask = MAY_EXEC;
+ else if (strcmp(mask, "MAY_WRITE") == 0)
+ entry->mask = MAY_WRITE;
+ else if (strcmp(mask, "MAY_READ") == 0)
+ entry->mask = MAY_READ;
+ else if (strcmp(mask, "MAY_APPEND") == 0)
+ entry->mask = MAY_APPEND;
+ else
+ result = -EINVAL;
+ if (!result)
+ entry->flags |= IMA_MASK;
+ }
+ if (!result && fsmagic) {
+ int rc;
+
+ rc = strict_strtoul(fsmagic, 16, &entry->fsmagic);
+ if (rc)
+ result = -EINVAL;
+ else
+ entry->flags |= IMA_FSMAGIC;
+ }
+ if (!result && uid) {
+ int rc;
+ ulong lnum;
+
+ rc = strict_strtoul(uid, 10, &lnum);
+ if (rc)
+ result = -EINVAL;
+ else {
+ entry->uid = (uid_t) lnum;
+ if (entry->uid != lnum)
+ result = -EINVAL;
+ else
+ entry->flags |= IMA_UID;
+ }
+ }
+ if (!result) {
+ mutex_lock(&ima_measure_mutex);
+ list_add_tail(&entry->list, &measure_policy_rules);
+ mutex_unlock(&ima_measure_mutex);
+ }
+ return result;
+}
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
new file mode 100644
index 0000000..1cb4f03
--- /dev/null
+++ b/security/integrity/ima/ima_queue.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Serge Hallyn <[email protected]>
+ * Reiner Sailer <[email protected]>
+ * Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_queue.c
+ * implements queues that store IMA measurements and
+ * maintains aggregate over the stored measurements
+ * in the pre-configured TPM PCR (if available)
+ * The measurement list is append-only. No entry is
+ * ever removed or changed during the boot-cycle.
+ */
+#include <linux/module.h>
+
+#include "ima.h"
+
+struct list_head ima_measurements; /* list of all measurements */
+struct ima_h_table ima_htable; /* key: inode (before secure-hashing a file) */
+
+/* mutex protects atomicity of extending measurement list
+ * and extending the TPM PCR aggregate. Since tpm_extend can take
+ * long (and the tpm driver uses a mutex), we can't use the spinlock.
+ */
+static DEFINE_MUTEX(ima_extend_list_mutex);
+
+void ima_create_htable(void)
+{
+ int i;
+
+ INIT_LIST_HEAD(&ima_measurements);
+ atomic_set(&ima_htable.len, 0);
+ atomic_long_set(&ima_htable.violations, 0);
+ ima_htable.max_htable_size = IMA_MEASURE_HTABLE_SIZE;
+
+ for (i = 0; i < ima_htable.max_htable_size; i++) {
+ INIT_HLIST_HEAD(&ima_htable.queue[i]);
+ atomic_set(&ima_htable.queue_len[i], 0);
+ }
+}
+
+struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
+{
+ struct ima_queue_entry *qe, *ret = NULL;
+ unsigned int key;
+ struct hlist_node *pos;
+
+ key = IMA_HASH_KEY(digest_value);
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(qe, pos, &ima_htable.queue[key], hnext) {
+ if (memcmp(qe->entry->digest, digest_value, 20) == 0) {
+ ret = qe;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+/* Called with mutex held */
+static int ima_add_digest_entry(struct ima_measure_entry *entry)
+{
+ struct ima_queue_entry *qe;
+ unsigned int key;
+
+ key = IMA_HASH_KEY(entry->digest);
+ qe = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (qe == NULL) {
+ ima_error("OUT OF MEMORY ERROR creating queue entry.\n");
+ return -ENOMEM;
+ }
+ qe->entry = entry;
+
+ hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
+ atomic_inc(&ima_htable.queue_len[key]);
+ return 0;
+}
+
+int ima_add_measure_entry(struct ima_measure_entry *entry, int violation)
+{
+ struct ima_queue_entry *qe;
+ int error = 0;
+
+ mutex_lock(&ima_extend_list_mutex);
+ if (!violation) {
+ if (ima_lookup_digest_entry(entry->digest)) {
+ error = -EEXIST;
+ goto out;
+ }
+ }
+ qe = kmalloc(sizeof(struct ima_queue_entry), GFP_KERNEL);
+ if (qe == NULL) {
+ ima_error("OUT OF MEMORY in %s.\n", __func__);
+ error = -ENOMEM;
+ goto out;
+ }
+ qe->entry = entry;
+
+ INIT_LIST_HEAD(&qe->later);
+ list_add_tail_rcu(&qe->later, &ima_measurements);
+
+ atomic_long_inc(&ima_htable.len);
+ if (ima_add_digest_entry(entry)) {
+ error = -ENOMEM;
+ goto out;
+ }
+ if (violation) { /* Replace 0x00 with 0xFF */
+ u8 digest[IMA_DIGEST_SIZE];
+
+ memset(digest, 0xff, sizeof digest);
+ ima_extend(digest);
+ } else
+ ima_extend(entry->digest);
+out:
+ mutex_unlock(&ima_extend_list_mutex);
+ return error;
+}
--
1.5.5.1
The internal TPM kernel interface did not protect itself from
the removal of the TPM driver, while being used. We continue
to protect the tpm_chip_list using the driver_lock as before,
and are using an rcu lock to protect readers. The internal TPM
kernel interface now protects itself from the driver being
removed by incrementing the module reference count.
Resubmitting integrity-tpm-internal-kernel-interface.patch, which
was previously Signed-off-by Kylene Hall.
Updated per feedback:
Adds the following support:
- make internal kernel interface to transmit TPM commands global
- adds reading a pcr value
- adds extending a pcr value
- adds lookup the tpm_chip for given chip number and type
Signed-off-by: Mimi Zohar <[email protected]>
Signed-off-by: Rajiv Andrade <[email protected]>
---
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 9c47dc4..17d2849 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1,11 +1,12 @@
/*
- * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2004,2007,2008 IBM Corporation
*
* Authors:
* Leendert van Doorn <[email protected]>
* Dave Safford <[email protected]>
* Reiner Sailer <[email protected]>
* Kylene Hall <[email protected]>
+ * Debora Velarde <[email protected]>
*
* Maintained by: <[email protected]>
*
@@ -28,6 +29,14 @@
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <linux/fs.h>
+#include <linux/scatterlist.h>
+#include <linux/rcupdate.h>
+#include <asm/unaligned.h>
#include "tpm.h"
enum tpm_const {
@@ -50,6 +59,8 @@ enum tpm_duration {
static LIST_HEAD(tpm_chip_list);
static DEFINE_SPINLOCK(driver_lock);
static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
+#define TPM_CHIP_NUM_MASK 0x0000ffff
+#define TPM_CHIP_TYPE_SHIFT 16
/*
* Array with one entry per ordinal defining the maximum amount
@@ -366,8 +377,7 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
/*
* Internal kernel interface to transmit TPM commands
*/
-static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
- size_t bufsiz)
+ssize_t tpm_transmit(struct tpm_chip *chip, char *buf, size_t bufsiz)
{
ssize_t rc;
u32 count, ordinal;
@@ -425,6 +435,7 @@ out:
mutex_unlock(&chip->tpm_mutex);
return rc;
}
+EXPORT_SYMBOL_GPL(tpm_transmit);
#define TPM_DIGEST_SIZE 20
#define TPM_ERROR_SIZE 10
@@ -717,6 +728,7 @@ ssize_t tpm_show_temp_deactivated(struct device * dev,
}
EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
+#define READ_PCR_RESULT_SIZE 30
static const u8 pcrread[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 14, /* length */
@@ -772,6 +784,128 @@ out:
}
EXPORT_SYMBOL_GPL(tpm_show_pcrs);
+/*
+ * tpm_chip_lookup - return tpm_chip for given chip number and type
+ *
+ * Must be called with rcu_read_lock.
+ */
+static struct tpm_chip *tpm_chip_lookup(int chip_num, int chip_typ)
+{
+ struct tpm_chip *pos;
+ int rc;
+
+ list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
+ rc = (chip_num == TPM_ANY_NUM || pos->dev_num == chip_num)
+ && (chip_typ == TPM_ANY_TYPE);
+ if (rc)
+ return pos;
+ }
+ return NULL;
+}
+
+/**
+ * tpm_pcr_read - read a pcr value
+ * @chip_id: tpm chip identifier
+ * Upper 2 bytes: ANY, HW_ONLY or SW_ONLY
+ * Lower 2 bytes: tpm idx # or AN&
+ * @pcr_idx: pcr idx to retrieve
+ * @res_buf: TPM_PCR value
+ * size of res_buf is 20 bytes (or NULL if you don't care)
+ *
+ * The TPM driver should be built-in, but for whatever reason it
+ * isn't, protect against the chip disappearing, by incrementing
+ * the module usage count.
+ */
+int tpm_pcr_read(u32 chip_id, int pcr_idx, u8 *res_buf)
+{
+ u8 data[READ_PCR_RESULT_SIZE];
+ int rc;
+ __be32 index;
+ int chip_num = chip_id & TPM_CHIP_NUM_MASK;
+ struct tpm_chip *chip;
+
+ rcu_read_lock();
+ chip = tpm_chip_lookup(chip_num, chip_id >> TPM_CHIP_TYPE_SHIFT);
+ if (chip == NULL) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+ if (!try_module_get(chip->dev->driver->owner)) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+ rcu_read_unlock();
+
+ BUILD_BUG_ON(sizeof(pcrread) > READ_PCR_RESULT_SIZE);
+ memcpy(data, pcrread, sizeof(pcrread));
+ index = cpu_to_be32(pcr_idx);
+ memcpy(data + 10, &index, 4);
+ rc = tpm_transmit(chip, data, sizeof(data));
+ if (rc > 0)
+ rc = get_unaligned_be32((__be32 *) (data + 6));
+
+ if (rc == 0 && res_buf)
+ memcpy(res_buf, data + 10, TPM_DIGEST_SIZE);
+
+ module_put(chip->dev->driver->owner);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_read);
+
+#define EXTEND_PCR_SIZE 34
+static const u8 pcrextend[] = {
+ 0, 193, /* TPM_TAG_RQU_COMMAND */
+ 0, 0, 0, 34, /* length */
+ 0, 0, 0, 20, /* TPM_ORD_Extend */
+ 0, 0, 0, 0 /* PCR index */
+};
+
+/**
+ * tpm_pcr_extend - extend pcr value with hash
+ * @chip_id: tpm chip identifier
+ * Upper 2 bytes: ANY, HW_ONLY or SW_ONLY
+ * Lower 2 bytes: tpm idx # or AN&
+ * @pcr_idx: pcr idx to extend
+ * @hash: hash value used to extend pcr value
+ *
+ * The TPM driver should be built-in, but for whatever reason it
+ * isn't, protect against the chip disappearing, by incrementing
+ * the module usage count.
+ */
+int tpm_pcr_extend(u32 chip_id, int pcr_idx, const u8 *hash)
+{
+ u8 data[EXTEND_PCR_SIZE];
+ int rc;
+ __be32 index;
+ int chip_num = chip_id & TPM_CHIP_NUM_MASK;
+ struct tpm_chip *chip;
+
+ rcu_read_lock();
+ chip = tpm_chip_lookup(chip_num, chip_id >> TPM_CHIP_TYPE_SHIFT);
+ if (chip == NULL) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+ if (!try_module_get(chip->dev->driver->owner)) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+ rcu_read_unlock();
+
+ BUILD_BUG_ON(sizeof(pcrextend) > EXTEND_PCR_SIZE);
+ memcpy(data, pcrextend, sizeof(pcrextend));
+ index = cpu_to_be32(pcr_idx);
+ memcpy(data + 10, &index, 4);
+ memcpy(data + 14, hash, TPM_DIGEST_SIZE);
+ rc = tpm_transmit(chip, data, sizeof(data));
+ if (rc > 0)
+ rc = get_unaligned_be32((__be32 *) (data + 6));
+
+ module_put(chip->dev->driver->owner);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_extend);
+
#define READ_PUBEK_RESULT_SIZE 314
static const u8 readpubek[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 8e30df4..e0ffddb 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2004, 2007, 2008 IBM Corporation
*
* Authors:
* Leendert van Doorn <[email protected]>
@@ -26,6 +26,7 @@
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/tpm.h>
enum tpm_timeout {
TPM_TIMEOUT = 5, /* msecs */
@@ -128,6 +129,7 @@ extern void tpm_get_timeouts(struct tpm_chip *);
extern void tpm_gen_interrupt(struct tpm_chip *);
extern void tpm_continue_selftest(struct tpm_chip *);
extern unsigned long tpm_calc_ordinal_duration(struct tpm_chip *, u32);
+ssize_t tpm_transmit(struct tpm_chip *chip, char *buf, size_t bufsiz);
extern struct tpm_chip* tpm_register_hardware(struct device *,
const struct tpm_vendor_specific *);
extern int tpm_open(struct inode *, struct file *);
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 717af7a..bc26116 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -642,6 +642,9 @@ static __devexit void tpm_tis_pnp_remove(struct pnp_dev *dev)
static struct pnp_driver tis_pnp_driver = {
.name = "tpm_tis",
+ .driver = {
+ .owner = THIS_MODULE,
+ },
.id_table = tpm_pnp_tbl,
.probe = tpm_tis_pnp_init,
.suspend = tpm_tis_pnp_suspend,
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
new file mode 100644
index 0000000..355a442
--- /dev/null
+++ b/include/linux/tpm.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2004,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Leendert van Doorn <[email protected]>
+ * Dave Safford <[email protected]>
+ * Reiner Sailer <[email protected]>
+ * Kylene Hall <[email protected]>
+ * Debora Velarde <[email protected]>
+ *
+ * Maintained by: <[email protected]>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at http://www.trustedcomputinggroup.org
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ */
+#ifndef __LINUX_TPM_H__
+#define __LINUX_TPM_H__
+
+#define PCI_DEVICE_ID_AMD_8111_LPC 0x7468
+
+/*
+ * Chip type is one of these values in the upper two bytes of chip_id
+ */
+enum tpm_chip_type {
+ TPM_HW_TYPE = 0x0,
+ TPM_SW_TYPE = 0x1,
+ TPM_ANY_TYPE = 0xFFFF,
+};
+
+/*
+ * Chip num is this value or a valid tpm idx in lower two bytes of chip_id
+ */
+enum tpm_chip_num {
+ TPM_ANY_NUM = 0xFFFF,
+};
+
+
+#if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
+
+extern int tpm_pcr_read(u32 chip_id, int pcr_idx, u8 *res_buf);
+extern int tpm_pcr_extend(u32 chip_id, int pcr_idx, const u8 *hash);
+#endif
+#endif
--
1.5.5.1
This version resolves the merge issues resulting from the removal
of the nameidata parameter to inode_permission(), by moving the
integrity_inode_permission() call from inode_permission() to
may_open(), and renaming the hook to integrity_nameidata_check().
The nameidata is needed in order to open and read the file, so
that the file can be hashed(a cryptographically strong checksum.)
This patch also fixes the template locking, preventing the template
from being freed while being used.
This patch is a redesign of the integrity framework, which address a
number of issues, including
- generalizing the measurement API beyond just inode measurements.
- separation of the measurement into distinct collection, appraisal,
and commitment phases, for greater flexibility.
Extended Verification Module(EVM) and the Integrity Measurement
Architecture(IMA) were originally implemented as an LSM module. Based
on discussions on the LSM mailing list, a decision was made that the
LSM hooks should only be used to enforce mandatory access control
decisions and a new set of hooks should be defined specifically for
integrity.
EVM/IMA was limited to verifying and measuring a file's (i.e. an inode)
integrity and the metadata associated with it. Current research is
looking into other types of integrity measurements. (i.e. "Linux kernel
integrity measurement using contextual inspection", by Peter A. Loscocco,
Perry W. Wilson, J. Aaron Pendergrass, C. Durward McDonell,
http://doi.acm.org/10.1145/1314354.1314362). As a result, a requirement
of the new integrity framework is support for different types of integrity
measurements.
This patch provides an integrity framework(api and hooks) and placement
of the integrity hooks in the appropriate places in the fs directory.
Collecting, appraising, and storing of file and other types of integrity
data is supported. Multiple integrity templates, which implement the
integrity API, may register themselves. For now, only a single integrity
provider can register itself for the integrity hooks. (Support for multiple
providers registering themselves for the integrity hooks would require
some form of stacking.)
The six integrity hooks are:
nameidata_check_integrity, inode_alloc_integrity, inode_free_integrity,
bprm_check_integrity, file_free_integrity, file_mmap
The five integrity API calls provided are:
integrity_must_measure, integrity_collect_measurement,
integrity_appraise_measurement, integrity_store_measurement,
and integrity_display_template.
The type of integrity data being collected, appraised, stored, or
displayed is template dependent.
(Details on the calls and their exact arguments are in linux/integrity.h,
included in the patch.)
Signed-off-by: Mimi Zohar <[email protected]>
---
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 784443a..6d4d675 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -44,6 +44,7 @@ parameter is applicable:
FB The frame buffer device is enabled.
HW Appropriate hardware is enabled.
IA-64 IA-64 architecture is enabled.
+ INTEGRITY Integrity support is enabled.
IOSCHED More than one I/O scheduler is enabled.
IP_PNP IP DHCP, BOOTP, or RARP is enabled.
ISAPNP ISA PnP code is enabled.
@@ -911,6 +912,11 @@ and is between 256 and 4096 characters. It is defined in the file
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
+ integrity_audit= [INTEGRITY]
+ Format: { "0" | "1" }
+ 0 -- integrity auditing messages. (Default)
+ 1 -- enable informational integrity auditing messages.
+
inttest= [IA64]
iommu= [x86]
diff --git a/fs/exec.c b/fs/exec.c
index 4e834f1..9abcaea 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -45,6 +45,7 @@
#include <linux/proc_fs.h>
#include <linux/mount.h>
#include <linux/security.h>
+#include <linux/integrity.h>
#include <linux/syscalls.h>
#include <linux/tsacct_kern.h>
#include <linux/cn_proc.h>
@@ -129,6 +130,9 @@ asmlinkage long sys_uselib(const char __user * library)
error = vfs_permission(&nd, MAY_READ | MAY_EXEC | MAY_OPEN);
if (error)
goto exit;
+ error = integrity_nameidata_check(&nd, MAY_READ | MAY_EXEC | MAY_OPEN);
+ if (error)
+ goto exit;
file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
error = PTR_ERR(file);
@@ -1199,6 +1203,9 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
retval = security_bprm_check(bprm);
if (retval)
return retval;
+ retval = integrity_bprm_check(bprm);
+ if (retval)
+ return retval;
/* kernel module loader fixup */
/* so we don't try to load run modprobe in kernel space. */
diff --git a/fs/file_table.c b/fs/file_table.c
index 5ad0eca..74b30ba 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/security.h>
+#include <linux/integrity.h>
#include <linux/eventpoll.h>
#include <linux/rcupdate.h>
#include <linux/mount.h>
@@ -276,6 +277,7 @@ void __fput(struct file *file)
if (file->f_op && file->f_op->release)
file->f_op->release(inode, file);
security_file_free(file);
+ integrity_file_free(file);
if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL))
cdev_put(inode->i_cdev);
fops_put(file->f_op);
@@ -347,6 +349,7 @@ void put_filp(struct file *file)
{
if (atomic_long_dec_and_test(&file->f_count)) {
security_file_free(file);
+ integrity_file_free(file);
file_kill(file);
file_free(file);
}
diff --git a/fs/inode.c b/fs/inode.c
index 0487ddb..bc2c3a5 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -17,6 +17,7 @@
#include <linux/hash.h>
#include <linux/swap.h>
#include <linux/security.h>
+#include <linux/integrity.h>
#include <linux/pagemap.h>
#include <linux/cdev.h>
#include <linux/bootmem.h>
@@ -143,12 +144,13 @@ static struct inode *alloc_inode(struct super_block *sb)
inode->i_cdev = NULL;
inode->i_rdev = 0;
inode->dirtied_when = 0;
- if (security_inode_alloc(inode)) {
- if (inode->i_sb->s_op->destroy_inode)
- inode->i_sb->s_op->destroy_inode(inode);
- else
- kmem_cache_free(inode_cachep, (inode));
- return NULL;
+ if (security_inode_alloc(inode))
+ goto out_free_inode;
+
+ /* allocate, attach and initialize an i_integrity */
+ if (integrity_inode_alloc(inode)) {
+ security_inode_free(inode);
+ goto out_free_inode;
}
spin_lock_init(&inode->i_lock);
@@ -185,12 +187,20 @@ static struct inode *alloc_inode(struct super_block *sb)
inode->i_mapping = mapping;
}
return inode;
+
+out_free_inode:
+ if (inode->i_sb->s_op->destroy_inode)
+ inode->i_sb->s_op->destroy_inode(inode);
+ else
+ kmem_cache_free(inode_cachep, (inode));
+ return NULL;
}
void destroy_inode(struct inode *inode)
{
BUG_ON(inode_has_buffers(inode));
security_inode_free(inode);
+ integrity_inode_free(inode);
if (inode->i_sb->s_op->destroy_inode)
inode->i_sb->s_op->destroy_inode(inode);
else
diff --git a/fs/namei.c b/fs/namei.c
index 09ce58e..bae619c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -24,6 +24,7 @@
#include <linux/fsnotify.h>
#include <linux/personality.h>
#include <linux/security.h>
+#include <linux/integrity.h>
#include <linux/syscalls.h>
#include <linux/mount.h>
#include <linux/audit.h>
@@ -1523,6 +1524,11 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
error = vfs_permission(nd, acc_mode);
if (error)
return error;
+
+ error = integrity_nameidata_check(nd, acc_mode
+ & (MAY_READ | MAY_WRITE | MAY_EXEC));
+ if (error)
+ return error;
/*
* An append-only file must be opened in append mode for writing.
*/
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 6fbebac..0f6b57e 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -125,6 +125,11 @@
#define AUDIT_LAST_KERN_ANOM_MSG 1799
#define AUDIT_ANOM_PROMISCUOUS 1700 /* Device changed promiscuous mode */
#define AUDIT_ANOM_ABEND 1701 /* Process ended abnormally */
+#define AUDIT_INTEGRITY_DATA 1800 /* Data integrity verification */
+#define AUDIT_INTEGRITY_METADATA 1801 /* Metadata integrity verification */
+#define AUDIT_INTEGRITY_STATUS 1802 /* Integrity enable status */
+#define AUDIT_INTEGRITY_HASH 1803 /* Integrity HASH type */
+#define AUDIT_INTEGRITY_PCR 1804 /* PCR invalidation msgs */
#define AUDIT_KERNEL 2000 /* Asynchronous audit record. NOT A REQUEST. */
@@ -442,6 +447,8 @@ extern int audit_set_loginuid(struct task_struct *task, uid_t loginuid);
#define audit_get_loginuid(t) ((t)->loginuid)
#define audit_get_sessionid(t) ((t)->sessionid)
extern void audit_log_task_context(struct audit_buffer *ab);
+extern void audit_log_inode_context(struct audit_buffer *ab,
+ struct inode *inode);
extern int __audit_ipc_obj(struct kern_ipc_perm *ipcp);
extern int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode);
extern int audit_bprm(struct linux_binprm *bprm);
@@ -554,6 +561,7 @@ extern int audit_signals;
#define audit_get_loginuid(t) (-1)
#define audit_get_sessionid(t) (-1)
#define audit_log_task_context(b) do { ; } while (0)
+#define audit_log_inode_context(b, a) do { } while (0)
#define audit_ipc_obj(i) ({ 0; })
#define audit_ipc_set_perm(q,u,g,m) ({ 0; })
#define audit_bprm(p) ({ 0; })
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0dcdd94..bc6460c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -683,6 +683,9 @@ struct inode {
#ifdef CONFIG_SECURITY
void *i_security;
#endif
+#ifdef CONFIG_INTEGRITY
+ void *i_integrity;
+#endif
void *i_private; /* fs or device private pointer */
};
diff --git a/include/linux/integrity.h b/include/linux/integrity.h
new file mode 100644
index 0000000..2fb0ccb
--- /dev/null
+++ b/include/linux/integrity.h
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#ifndef _LINUX_INTEGRITY_H
+#define _LINUX_INTEGRITY_H
+
+#include <linux/fs.h>
+#include <linux/audit.h>
+
+#ifdef CONFIG_INTEGRITY
+void integrity_audit_msg(int audit_msgno, struct inode *inode,
+ const unsigned char *fname, char *op,
+ char *cause, int result);
+
+/*
+ * Integrity API calls:
+ *
+ * @collect_measurement:
+ * Collect template specific measurement data.
+ * @data contains template specific data used for collecting the
+ * measurement.
+ * Return 0 if operation was successful.
+ *
+ * @appraise_measurement:
+ * Appraise the integrity of the template specific measurement data.
+ * @data contains template specific data used for appraising the
+ * measurement.
+ * Return 0 if operation was successful.
+ *
+ * @store_measurement:
+ * Store the template specific data.
+ * @data contains template specific data used for storing the
+ * measurement.
+ *
+ * @must_measure:
+ * Measurement decision based on an integrity policy.
+ * @data contains template specific data used for making policy
+ * decision.
+ * Return 0 if operation was successful.
+ *
+ * @display_template:
+ * Display template specific data.
+ *
+ */
+
+enum integrity_show_type { INTEGRITY_SHOW_BINARY, INTEGRITY_SHOW_ASCII };
+
+struct template_operations {
+ int (*collect_measurement) (void *);
+ int (*appraise_measurement) (void *);
+ void (*store_measurement) (void *);
+ int (*must_measure) (void *);
+ void (*display_template) (struct seq_file *m, void *,
+ enum integrity_show_type);
+};
+extern int integrity_register_template(const char *template_name,
+ const struct template_operations *ops);
+extern int integrity_unregister_template(const char *template_name);
+
+/*
+ * Integrity hooks:
+ *
+ * @bprm_check_integrity:
+ * This hook mediates the point when a search for a binary handler will
+ * begin. At this point, the OS protects against an executable file,
+ * already open for write, from being executed; and an executable file
+ * already open for execute, from being modified. So we can be certain
+ * that any measurements(collect, appraise, store) done here are of
+ * the file being executed.
+ * @bprm contains the linux_binprm structure.
+ * Return 0 if the hook is successful and permission is granted.
+ *
+ * @inode_alloc_integrity:
+ * Allocate an integrity structure associated with an inode.
+ * @inode contains the inode structure.
+ * Return 0 if operation was successful.
+ *
+ * @inode_free_integrity:
+ * @inode contains the inode structure.
+ * Deallocate the integrity structure associated with the inode
+ *
+ * @nameidata_check_integrity:
+ * This hook is called by the existing Linux may_open function,
+ * after calling verify_permission(), as a file is opened. At
+ * this point, measurements(collect, appraise, store) of files
+ * open for read can be made.
+ * @nd contains the nameidata structure.
+ * @mask contains the permission mask.
+ * Return 0 if the hook is successful and permission is granted.
+ *
+ * @file_free_integrity:
+ * Update the integrity xattr value as necessary.
+ * @file contains the file structure being closed.
+ *
+ * @file_mmap :
+ * Measurements(collect, appraise, store) of files mmaped for EXEC
+ * can be made.
+ * @file contains the file structure of the file to map (may be NULL).
+ * @prot contains the protection that will be applied by the kernel.
+ * Return 0 if the hook is successful and permission is granted.
+ */
+
+enum lim_hooks { INODE_PERMISSION = 1, FILE_MMAP, BPRM_CHECK };
+
+struct integrity_operations {
+ int (*bprm_check_integrity) (struct linux_binprm *bprm);
+ int (*inode_alloc_integrity) (struct inode *inode);
+ void (*inode_free_integrity) (struct inode *inode);
+ int (*nameidata_check_integrity) (struct nameidata *nd, int mask);
+ void (*file_free_integrity) (struct file *file);
+ int (*file_mmap) (struct file *file, unsigned long prot);
+};
+extern int register_integrity(const struct integrity_operations *ops);
+extern int unregister_integrity(const struct integrity_operations *ops);
+
+/* global variables */
+int integrity_collect_measurement(const char *template_name, void *data);
+int integrity_appraise_measurement(const char *template_name, void *data);
+int integrity_must_measure(const char *template_name, void *data);
+int integrity_store_measurement(const char *template_name, void *data);
+
+int integrity_bprm_check(struct linux_binprm *bprm);
+int integrity_inode_alloc(struct inode *inode);
+void integrity_inode_free(struct inode *inode);
+int integrity_nameidata_check(struct nameidata *nd, int mask);
+void integrity_file_free(struct file *file);
+int integrity_file_mmap(struct file *file, unsigned long prot);
+#else
+
+static inline int integrity_bprm_check(struct linux_binprm *bprm)
+{
+ return 0;
+}
+
+static inline int integrity_inode_alloc(struct inode *inode)
+{
+ return 0;
+}
+
+static inline void integrity_inode_free(struct inode *inode)
+{
+ return;
+}
+
+static inline int integrity_nameidata_check(struct nameidata *nd, int mask)
+{
+ return 0;
+}
+
+static inline void integrity_file_free(struct file *file)
+{
+ return;
+}
+
+static inline int integrity_file_mmap(struct file *file, unsigned long prot)
+{
+ return 0;
+}
+#endif
+#endif
diff --git a/mm/mmap.c b/mm/mmap.c
index de14ac2..9d74949 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -20,6 +20,7 @@
#include <linux/fs.h>
#include <linux/personality.h>
#include <linux/security.h>
+#include <linux/integrity.h>
#include <linux/hugetlb.h>
#include <linux/profile.h>
#include <linux/module.h>
@@ -1050,6 +1051,9 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
error = security_file_mmap(file, reqprot, prot, flags, addr, 0);
if (error)
return error;
+ error = integrity_file_mmap(file, prot);
+ if (error)
+ return error;
return mmap_region(file, addr, len, flags, vm_flags, pgoff,
accountable);
diff --git a/security/Kconfig b/security/Kconfig
index d9f47ce..4c602be 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -126,5 +126,7 @@ config SECURITY_DEFAULT_MMAP_MIN_ADDR
source security/selinux/Kconfig
source security/smack/Kconfig
+source security/integrity/Kconfig
+
endmenu
diff --git a/security/Makefile b/security/Makefile
index c05c127..db9efb5 100644
--- a/security/Makefile
+++ b/security/Makefile
@@ -17,3 +17,7 @@ obj-$(CONFIG_SECURITY_SELINUX) += selinux/built-in.o
obj-$(CONFIG_SECURITY_SMACK) += smack/built-in.o
obj-$(CONFIG_SECURITY_ROOTPLUG) += root_plug.o
obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o
+
+# Object integrity file lists
+subdir-$(CONFIG_INTEGRITY) += integrity
+obj-$(CONFIG_INTEGRITY) += integrity/built-in.o
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
new file mode 100644
index 0000000..7dcb50e
--- /dev/null
+++ b/security/integrity/Kconfig
@@ -0,0 +1,24 @@
+#
+# Integrity configuration
+#
+
+config INTEGRITY
+ bool "Enable different integrity models"
+ help
+ This allows you to choose different integrity modules to be
+ configured into your kernel. Integrity models can collect,
+ verify, and record measurements, such as of a file's data
+ and metadata before it is read or executed.
+
+ If you are unsure how to answer this question, answer N.
+
+config INTEGRITY_AUDIT
+ bool "Integrity audit boot parameter"
+ depends on INTEGRITY
+ default n
+ help
+ This option adds a kernel parameter 'integrity_audit', which
+ allows informational integrity auditing messages to be enabled
+ at boot. If this option is selected, informational integrity
+ auditing messages can be enabled with 'integrity_audit=1' on
+ the kernel command line.
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
new file mode 100644
index 0000000..a6e1405
--- /dev/null
+++ b/security/integrity/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for the kernel integrity code
+#
+
+# Object file lists
+obj-$(CONFIG_INTEGRITY) += integrity.o integrity_audit.o
diff --git a/security/integrity/integrity.c b/security/integrity/integrity.c
new file mode 100644
index 0000000..c819620
--- /dev/null
+++ b/security/integrity/integrity.c
@@ -0,0 +1,315 @@
+/*
+ * Copyright (C) 2006,2007,2008 IBM Corporation
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * File: integrity.c
+ * register integrity subsystem
+ * register integrity template
+ */
+
+#include <asm/atomic.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/integrity.h>
+#include "integrity.h"
+
+static const struct integrity_operations *integrity_ops;
+static LIST_HEAD(integrity_templates);
+static DEFINE_MUTEX(integrity_templates_mutex);
+
+/**
+ * register_integrity - registers an integrity framework with the kernel
+ * @ops: a pointer to the struct security_options that is to be registered
+ *
+ * Perhaps in the future integrity module stacking will be necessary, but
+ * for the time being, this function permits only one integrity module to
+ * register itself with the kernel integrity subsystem.
+ *
+ * If another integrity module is already registered, an error code is
+ * returned. On success 0 is returned.
+ */
+int register_integrity(const struct integrity_operations *ops)
+{
+ if (integrity_ops != NULL)
+ return -EAGAIN;
+ integrity_ops = ops;
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(register_integrity);
+
+/**
+ * unregister_integrity - unregisters an integrity framework from the kernel
+ * @ops: a pointer to the struct security_options that is to be registered
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ */
+int unregister_integrity(const struct integrity_operations *ops)
+{
+ if (ops != integrity_ops)
+ return -EINVAL;
+
+ integrity_ops = NULL;
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(unregister_integrity);
+
+/**
+ * integrity_register_template - registers an integrity template with the kernel
+ * @template_name: a pointer to a string containing the template name.
+ * @template_ops: a pointer to the template functions
+ *
+ * Register a set of functions to collect, appraise, store, and display
+ * a template measurement, and a means to decide whether to do them.
+ * Unlike integrity modules, any number of templates may be registered.
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int integrity_register_template(const char *template_name,
+ const struct template_operations *template_ops)
+{
+ int template_len;
+ struct template_list_entry *entry;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&entry->template);
+
+ atomic_set(&entry->refcount, 1);
+ template_len = strlen(template_name);
+ if (template_len > TEMPLATE_NAME_LEN_MAX) {
+ kfree(entry);
+ return -EINVAL;
+ }
+ strcpy(entry->template_name, template_name);
+ entry->template_ops = template_ops;
+
+ mutex_lock(&integrity_templates_mutex);
+ list_add_rcu(&entry->template, &integrity_templates);
+ mutex_unlock(&integrity_templates_mutex);
+ synchronize_rcu();
+
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(integrity_register_template);
+
+/**
+ * integrity_unregister_template: unregister a template
+ * @template_name: a pointer to a string containing the template name.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ */
+int integrity_unregister_template(const char *template_name)
+{
+ struct template_list_entry *entry;
+
+ mutex_lock(&integrity_templates_mutex);
+ list_for_each_entry(entry, &integrity_templates, template) {
+ if (strncmp(entry->template_name, template_name,
+ strlen(entry->template_name)) == 0) {
+ list_del_rcu(&entry->template);
+ mutex_unlock(&integrity_templates_mutex);
+ synchronize_rcu();
+ tput(entry);
+ return 0;
+ }
+ }
+ mutex_unlock(&integrity_templates_mutex);
+ return -EINVAL;
+}
+
+EXPORT_SYMBOL_GPL(integrity_unregister_template);
+
+/**
+ * integrity_find_template - search the integrity_templates list
+ * @template_name: a pointer to a string containing the template name.
+ * @template_entry: a pointer to an entry in the template list
+ *
+ * Called with an rcu_read_lock
+ * Returns 0 on success, -EINVAL on failure.
+ */
+int integrity_find_template(const char *template_name,
+ struct template_list_entry **template_entry)
+{
+ struct template_list_entry *entry;
+
+ list_for_each_entry_rcu(entry, &integrity_templates, template) {
+ if (strncmp(entry->template_name, template_name,
+ strlen(entry->template_name)) == 0) {
+ *template_entry = entry;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+EXPORT_SYMBOL_GPL(integrity_find_template);
+
+/* Start of the integrity API calls */
+
+/**
+ * integrity_collect_measurement - collect template specific measurement
+ * @template_name: a pointer to a string containing the template name.
+ * @data: pointer to template specific data
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int integrity_collect_measurement(const char *template_name, void *data)
+{
+ struct template_list_entry *template_entry;
+ int rc;
+
+ rcu_read_lock();
+ rc = integrity_find_template(template_name, &template_entry);
+ tget(template_entry);
+ rcu_read_unlock();
+
+ if (rc == 0 && template_entry)
+ rc = template_entry->template_ops->collect_measurement(data);
+ tput(template_entry);
+ return rc;
+}
+
+EXPORT_SYMBOL_GPL(integrity_collect_measurement);
+
+/**
+ * integrity_appraise_measurement - appraise template specific measurement
+ * @template_name: a pointer to a string containing the template name.
+ * @data: pointer to template specific data
+ *
+ * Returns 0 on success, an error code on failure
+ */
+int integrity_appraise_measurement(const char *template_name, void *data)
+{
+ struct template_list_entry *template_entry;
+ int rc;
+
+ rcu_read_lock();
+ rc = integrity_find_template(template_name, &template_entry);
+ tget(template_entry);
+ rcu_read_unlock();
+
+ if (rc == 0 && template_entry)
+ rc = template_entry->template_ops->appraise_measurement(data);
+ tput(template_entry);
+ return rc;
+}
+
+EXPORT_SYMBOL_GPL(integrity_appraise_measurement);
+
+/**
+ * integrity_store_measurement - store template specific measurement
+ * @template_name: a pointer to a string containing the template name.
+ * @data: pointer to template specific data
+ *
+ * Store template specific integrity measurement.
+ */
+int integrity_store_measurement(const char *template_name, void *data)
+{
+ struct template_list_entry *template_entry;
+ int rc;
+
+ rcu_read_lock();
+ rc = integrity_find_template(template_name, &template_entry);
+ tget(template_entry);
+ rcu_read_unlock();
+
+ if (rc == 0 && template_entry)
+ template_entry->template_ops->store_measurement(data);
+ tput(template_entry);
+ return rc;
+}
+
+EXPORT_SYMBOL_GPL(integrity_store_measurement);
+
+/**
+ * integrity_must_measure - measure decision based on template policy
+ * @template_name: a pointer to a string containing the template name.
+ * @data: pointer to template specific data
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int integrity_must_measure(const char *template_name, void *data)
+{
+ struct template_list_entry *template_entry;
+ int rc;
+
+ rcu_read_lock();
+ rc = integrity_find_template(template_name, &template_entry);
+ tget(template_entry);
+ rcu_read_unlock();
+
+ if (rc == 0 && template_entry)
+ rc = template_entry->template_ops->must_measure(data);
+ tput(template_entry);
+ return rc;
+}
+
+EXPORT_SYMBOL_GPL(integrity_must_measure);
+
+/* Start of the integrity Hooks */
+
+/* Hook used to measure executable file integrity. */
+int integrity_bprm_check(struct linux_binprm *bprm)
+{
+ int rc = 0;
+
+ if (integrity_ops && integrity_ops->bprm_check_integrity)
+ rc = integrity_ops->bprm_check_integrity(bprm);
+ return rc;
+}
+
+/* Allocate, attach and initialize an inode's i_integrity,
+ * if INTEGRITY is configured.
+ */
+int integrity_inode_alloc(struct inode *inode)
+{
+ int rc = 0;
+
+ if (integrity_ops && integrity_ops->inode_alloc_integrity)
+ rc = integrity_ops->inode_alloc_integrity(inode);
+ return rc;
+}
+
+/* Hook used to free an inode's i_integrity structure. */
+void integrity_inode_free(struct inode *inode)
+{
+ if (integrity_ops && integrity_ops->inode_free_integrity)
+ integrity_ops->inode_free_integrity(inode);
+}
+
+/* Hook used to measure a file's integrity. */
+int integrity_nameidata_check(struct nameidata *nd, int mask)
+{
+ int rc = 0;
+
+ if (integrity_ops && integrity_ops->nameidata_check_integrity)
+ rc = integrity_ops->nameidata_check_integrity(nd, mask);
+ return rc;
+}
+
+/* Hook used to update i_integrity data and integrity xattr values
+ * as necessary.
+ */
+void integrity_file_free(struct file *file)
+{
+ if (integrity_ops && integrity_ops->file_free_integrity)
+ integrity_ops->file_free_integrity(file);
+}
+
+/* Hook used to measure integrity of an mmapped file */
+int integrity_file_mmap(struct file *file, unsigned long prot)
+{
+ int rc = 0;
+
+ if (integrity_ops && integrity_ops->file_mmap)
+ rc = integrity_ops->file_mmap(file, prot);
+ return rc;
+}
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
new file mode 100644
index 0000000..2335b1a
--- /dev/null
+++ b/security/integrity/integrity.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#define TEMPLATE_NAME_LEN_MAX 12
+struct template_list_entry {
+ struct list_head template;
+ char template_name[TEMPLATE_NAME_LEN_MAX + 1];
+ const struct template_operations *template_ops;
+ atomic_t refcount;
+};
+
+static inline void tget(struct template_list_entry *entry)
+{
+ if (!entry)
+ return;
+ atomic_inc(&entry->refcount);
+}
+
+static inline void tput(struct template_list_entry *entry)
+{
+ if (!entry)
+ return;
+ if (atomic_dec_and_test(&entry->refcount))
+ kfree(entry);
+}
+
+extern int integrity_find_template(const char *,
+ struct template_list_entry **entry);
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
new file mode 100644
index 0000000..b23ff67
--- /dev/null
+++ b/security/integrity/integrity_audit.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ * Author: Mimi Zohar <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * File: integrity_audit.c
+ * Audit calls for the integrity subsystem
+ */
+
+#include <linux/audit.h>
+#include <linux/fs.h>
+#include <linux/integrity.h>
+
+static int integrity_audit = 0;
+
+#ifdef CONFIG_INTEGRITY_AUDIT
+static int __init integrity_audit_setup(char *str)
+{
+ ulong audit;
+ int rc;
+ char *op;
+
+ rc = strict_strtoul(str, 0, &audit);
+ if (rc || audit > 1)
+ printk(KERN_INFO "integrity: invalid integrity_audit value\n");
+ else
+ integrity_audit = audit;
+
+ op = integrity_audit ? "integrity_audit_enabled" :
+ "integrity_audit_not_enabled";
+ integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, NULL, op, 0);
+ return 1;
+}
+
+__setup("integrity_audit=", integrity_audit_setup);
+#endif
+
+void integrity_audit_msg(int audit_msgno, struct inode *inode,
+ const unsigned char *fname, char *op,
+ char *cause, int result)
+{
+ struct audit_buffer *ab;
+
+ if (!integrity_audit && result == 1) /* Skip information messages */
+ return;
+
+ ab = audit_log_start(current->audit_context, GFP_KERNEL, audit_msgno);
+ audit_log_format(ab, "integrity: pid=%d uid=%u auid=%u",
+ current->pid, current->uid,
+ audit_get_loginuid(current));
+ //audit_log_task_context(ab);
+ switch (audit_msgno) {
+ case AUDIT_INTEGRITY_DATA:
+ case AUDIT_INTEGRITY_METADATA:
+ case AUDIT_INTEGRITY_PCR:
+ audit_log_format(ab, " op=%s cause=%s", op, cause);
+ break;
+ case AUDIT_INTEGRITY_HASH:
+ audit_log_format(ab, " op=%s hash=%s", op, cause);
+ break;
+ case AUDIT_INTEGRITY_STATUS:
+ default:
+ audit_log_format(ab, " op=%s", op);
+ }
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, current->comm);
+ if (fname) {
+ audit_log_format(ab, " name=");
+ audit_log_untrustedstring(ab, fname);
+ }
+ if (inode)
+ audit_log_format(ab, " dev=%s ino=%lu",
+ inode->i_sb->s_id, inode->i_ino);
+ audit_log_format(ab, " res=%d", result);
+ audit_log_end(ab);
+}
--
1.5.5.1
On Wed, 12 Nov 2008 22:47:12 -0500
Mimi Zohar <[email protected]> wrote:
> This version resolves the merge issues resulting from the removal
> of the nameidata parameter to inode_permission(), by moving the
> integrity_inode_permission() call from inode_permission() to
> may_open(), and renaming the hook to integrity_nameidata_check().
> The nameidata is needed in order to open and read the file, so
> that the file can be hashed(a cryptographically strong checksum.)
>
> This patch also fixes the template locking, preventing the template
> from being freed while being used.
>
> This patch is a redesign of the integrity framework, which address a
> number of issues, including
> - generalizing the measurement API beyond just inode measurements.
> - separation of the measurement into distinct collection, appraisal,
> and commitment phases, for greater flexibility.
>
> Extended Verification Module(EVM) and the Integrity Measurement
> Architecture(IMA) were originally implemented as an LSM module. Based
> on discussions on the LSM mailing list, a decision was made that the
> LSM hooks should only be used to enforce mandatory access control
> decisions and a new set of hooks should be defined specifically for
> integrity.
>
> EVM/IMA was limited to verifying and measuring a file's (i.e. an inode)
> integrity and the metadata associated with it. Current research is
> looking into other types of integrity measurements. (i.e. "Linux kernel
> integrity measurement using contextual inspection", by Peter A. Loscocco,
> Perry W. Wilson, J. Aaron Pendergrass, C. Durward McDonell,
> http://doi.acm.org/10.1145/1314354.1314362). As a result, a requirement
> of the new integrity framework is support for different types of integrity
> measurements.
> This patch provides an integrity framework(api and hooks) and placement
> of the integrity hooks in the appropriate places in the fs directory.
> Collecting, appraising, and storing of file and other types of integrity
> data is supported. Multiple integrity templates, which implement the
> integrity API, may register themselves. For now, only a single integrity
> provider can register itself for the integrity hooks. (Support for multiple
> providers registering themselves for the integrity hooks would require
> some form of stacking.)
>
> The six integrity hooks are:
> nameidata_check_integrity, inode_alloc_integrity, inode_free_integrity,
> bprm_check_integrity, file_free_integrity, file_mmap
>
> The five integrity API calls provided are:
> integrity_must_measure, integrity_collect_measurement,
> integrity_appraise_measurement, integrity_store_measurement,
> and integrity_display_template.
>
> The type of integrity data being collected, appraised, stored, or
> displayed is template dependent.
>
>
> ...
>
> +int integrity_register_template(const char *template_name,
> + const struct template_operations *template_ops)
> +{
> + int template_len;
> + struct template_list_entry *entry;
> +
> + entry = kzalloc(sizeof(*entry), GFP_KERNEL);
> + if (!entry)
> + return -ENOMEM;
> + INIT_LIST_HEAD(&entry->template);
> +
> + atomic_set(&entry->refcount, 1);
> + template_len = strlen(template_name);
> + if (template_len > TEMPLATE_NAME_LEN_MAX) {
It would be much neater to perform this check before running kzalloc().
> + kfree(entry);
> + return -EINVAL;
> + }
> + strcpy(entry->template_name, template_name);
> + entry->template_ops = template_ops;
> +
> + mutex_lock(&integrity_templates_mutex);
> + list_add_rcu(&entry->template, &integrity_templates);
> + mutex_unlock(&integrity_templates_mutex);
> + synchronize_rcu();
> +
> + return 0;
> +}
> +
> +EXPORT_SYMBOL_GPL(integrity_register_template);
someone forgot to run checkpatch.
>
> ...
>
> +static inline void tget(struct template_list_entry *entry)
> +{
> + if (!entry)
> + return;
> + atomic_inc(&entry->refcount);
> +}
> +
> +static inline void tput(struct template_list_entry *entry)
> +{
> + if (!entry)
> + return;
> + if (atomic_dec_and_test(&entry->refcount))
> + kfree(entry);
> +}
Do these _really_ need to test for a NULL pointer? It's an extra
test-n-branch in many fastpaths. It would be better to avoid doing
this here, if poss.
On Wed, 12 Nov 2008 22:47:13 -0500
Mimi Zohar <[email protected]> wrote:
> This is a re-release of Integrity Measurement Architecture(IMA) as an
> independent Linunx Integrity Module(LIM) service provider.
>
> As a LIM integrity provider, IMA implements the new LIM must_measure(),
> collect_measurement(), store_measurement(), and display_template() API
> calls. The store_measurement() call supports two types of data, IMA
> (i.e. file data) and generic template data.
>
> IMA provides hardware (TPM) based measurement and attestation for both
> files and other types of template measurements. As the Trusted Computing
> (TPM) model requires, IMA measures all files before they are accessed
> in any way (on the bprm_check_integrity, nameidata_check_integrity,
> file_mmap hooks), and commits the measurements to the TPM. In addition,
> IMA maintains a list of these hash values, which can be used to validate
> the aggregate PCR value. The TPM can sign these measurements, and thus
> the system can prove to itself and to a third party these measurements
> in a way that cannot be circumvented by malicious or compromised software.
>
> When store_measurement() is called for the IMA type of data, the file
> measurement and the file name hint are used to form an IMA template.
> IMA then calculates the IMA template measurement(hash) and submits it
> to the TPM chip for inclusion in one of the chip's Platform Configuration
> Registers (PCR).
>
> When store_measurement() is called for generic template data, IMA
> calculates the measurement(hash) of the template data, and submits
> the template measurement to the TPM chip for inclusion in one of the
> chip's Platform Configuration Registers(PCR).
>
> In order to view the contents of template data through securityfs, the
> template_display() function must be defined in the registered
> template_operations. In the case of the IMA template, the list of
> file names and files hashes submitted can be viewed through securityfs.
>
> As mentioned above, IMA maintains a list of hash values of executables
> and other sensitive system files loaded into the run-time of the system.
> Our work has shown that requests for integrity appraisal and measurement
> need to be based on knowledge of the filesystem, requiring the system
> to either be labeled with integrity data or depend on the existent LSM
> security labels. The previous set of integrity patches modified the LSM
> modules to be integrity context aware, meaning that the LSM modules made
> integrity data/metadata appraisal and measurement API calls based on
> an understanding of the LSM security labels. Both of the LSM maintainers
> felt that the changes were too intrusive and that integrity enforcement
> should be made by the integrity provider, not the LSM module.
>
> To address these concerns, Stephen Smalley suggested using the
> security_audit_rule_match(), renamed to security_filter_rule_match(), to
> define LSM specific integrity measurement policy rules, in lieu of
> modifying the LSM modules. In the current set of patches, the integrity
> API calls can be made either by IMA, based on an LSM specific integrity
> policy, or by an integrity context aware LSM.
>
> ...
>
> +static void ima_add_boot_aggregate(void)
> +{
> + /* cumulative sha1 over tpm registers 0-7 */
> + struct ima_measure_entry *entry;
> + size_t count;
> + int err;
> +
> + /* create new entry for boot aggregate */
> + entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
This uses GFP_ATOMIC, but crypto_alloc_hash() (called later) uses
GFP_KERNEL.
If this _had_ to be GFP_ATOMIC then you have a bug.
Otherwise, please use the much more reliable GFP_KERNEL here.
On Wed, 12 Nov 2008 22:47:14 -0500
Mimi Zohar <[email protected]> wrote:
> This version stores integrity information associated with an inode
> in a radix tree in order to avoid bloating the in memory inode.
> As entries can not be added to the radix tree at security_initcall,
> this version removes the dual stage initialization. Allocating and
> freeing the memory continues to be done at inode_alloc and file_free,
> respectively, except for inodes created before late_initcall.
>
> Signed-off-by: Mimi Zohar <[email protected]>
> ---
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index bc6460c..0dcdd94 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -683,9 +683,6 @@ struct inode {
> #ifdef CONFIG_SECURITY
> void *i_security;
> #endif
> -#ifdef CONFIG_INTEGRITY
> - void *i_integrity;
> -#endif
ah, I was going to ask about that..
> void *i_private; /* fs or device private pointer */
> };
>
> diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
> index f3aced4..959ae66 100644
> --- a/security/integrity/ima/Makefile
> +++ b/security/integrity/ima/Makefile
> @@ -6,4 +6,4 @@
> obj-$(CONFIG_IMA) += ima.o
>
> ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
> - ima_policy.o
> + ima_policy.o ima_iint.o
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 9a24305..09a5e1a 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -92,7 +92,6 @@ void ima_store_measurement(void *d);
> void ima_template_show(struct seq_file *m, void *e,
> enum integrity_show_type show);
>
> -
> /*
> * used to protect h_table and sha_table
> */
> @@ -109,7 +108,7 @@ extern struct ima_h_table ima_htable;
>
> static inline unsigned long IMA_HASH_KEY(u8 *digest)
> {
> - return(hash_long(*digest, IMA_HASH_BITS));
> + return (hash_long(*digest, IMA_HASH_BITS));
And I _did_ ask about that ;)
> }
>
> /* TPM "Glue" definitions */
> @@ -145,11 +144,36 @@ struct ima_iint_cache {
> u8 hmac[IMA_DIGEST_SIZE];
> u8 digest[IMA_DIGEST_SIZE];
> struct mutex mutex;
> + atomic_t refcount;
> };
> #define IMA_IINT_INIT 1
> #define IMA_MUST_MEASURE 2
> #define IMA_MEASURED 4
>
> +void ima_iint_init(void);
> +struct ima_iint_cache * ima_iint_lookup(struct inode *inode);
checkpatch...
>
> ...
>
> --- /dev/null
> +++ b/security/integrity/ima/ima_iint.c
> @@ -0,0 +1,68 @@
> +/*
> + * Copyright (C) 2008 IBM Corporation
> + *
> + * Authors:
> + * Mimi Zohar <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation, version 2 of the
> + * License.
> + *
> + * File: ima_iint.c
> + * cache integrity information associated with an inode
> + * using a radix tree.
> + */
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/radix-tree.h>
> +#include "ima.h"
> +
> +static struct radix_tree_root ima_iint_store;
> +DEFINE_SPINLOCK(ima_iint_lock);
> +
> +void ima_iint_init(void)
> +{
> + INIT_RADIX_TREE(&ima_iint_store, GFP_ATOMIC);
> +}
Use the RADIX_TREE() macro, then remove this function.
On Wed, 12 Nov 2008 22:47:10 -0500
Mimi Zohar <[email protected]> wrote:
> The Linux Integrity Module (LIM) Framework provides hooks
> for modules to perform collection, appraisal, and storage
> of system integrity measurements. One such module, IMA,
> collects measurements of file data, maintains this list
> in the kernel, and if available, stores (extends) the
> measurements into a hardware TPM. These measurements are
> collected, appraised, and stored before any access
> (read or execute) to the data, so that malicious code or
> data cannot remove or cover up its own measurement, to avoid
> detection. If the measurements are anchored in a TPM, the
> TPM can sign the measurements, for proof of integrity
> to a third party, such as in enterprise client management.
>
> Integrity measurement is complementary to LSM mandatory
> access control, which can be used to protect the integrity
> of system files. Integrity measurement policies can take
> advantage of LSM labels in deciding what to measure and
> to detect when the protection fails, with hardware strength.
This all looks quite mergeable to me, although I am far from being an
expert on security things.
One thing which I cannot say, and which is quite important: how useful
will all of this be to our users? Are people asking for it? Are
people likely to enable and use it? Are they even likely to understand
it? ;) Are any large/important customers asking for it? Are distros
likely to enable and support it?
etc?
On Wed, Nov 12, 2008 at 10:47:12PM -0500, Mimi Zohar wrote:
> This version resolves the merge issues resulting from the removal
> of the nameidata parameter to inode_permission(), by moving the
> integrity_inode_permission() call from inode_permission() to
> may_open(), and renaming the hook to integrity_nameidata_check().
Still neither a good parameter nor a good name. If you look at fsdevel
you'll see that a patch for the next merged window is already out and
in Al's to be applied queue that removes the nameidata there. A
strcut path and maybe the MAY_ lookup flags should be enough for you,
and a integrity_path_check also sounds like it really does what you
want.
Also please merge the last radix tree patch into this one so tat it's
possible to review the code that actually goes in instead of replacing
a large part of it in a follow-up patch.
On Fri, 2008-11-14 at 14:15 -0800, Andrew Morton wrote:
> On Wed, 12 Nov 2008 22:47:12 -0500
> Mimi Zohar <[email protected]> wrote:
>
> > This version resolves the merge issues resulting from the removal
> > of the nameidata parameter to inode_permission(), by moving the
> > integrity_inode_permission() call from inode_permission() to
> > may_open(), and renaming the hook to integrity_nameidata_check().
> > The nameidata is needed in order to open and read the file, so
> > that the file can be hashed(a cryptographically strong checksum.)
> >
> > This patch also fixes the template locking, preventing the template
> > from being freed while being used.
> >
> > This patch is a redesign of the integrity framework, which address a
> > number of issues, including
> > - generalizing the measurement API beyond just inode measurements.
> > - separation of the measurement into distinct collection, appraisal,
> > and commitment phases, for greater flexibility.
> >
> > Extended Verification Module(EVM) and the Integrity Measurement
> > Architecture(IMA) were originally implemented as an LSM module. Based
> > on discussions on the LSM mailing list, a decision was made that the
> > LSM hooks should only be used to enforce mandatory access control
> > decisions and a new set of hooks should be defined specifically for
> > integrity.
> >
> > EVM/IMA was limited to verifying and measuring a file's (i.e. an inode)
> > integrity and the metadata associated with it. Current research is
> > looking into other types of integrity measurements. (i.e. "Linux kernel
> > integrity measurement using contextual inspection", by Peter A. Loscocco,
> > Perry W. Wilson, J. Aaron Pendergrass, C. Durward McDonell,
> > http://doi.acm.org/10.1145/1314354.1314362). As a result, a requirement
> > of the new integrity framework is support for different types of integrity
> > measurements.
> > This patch provides an integrity framework(api and hooks) and placement
> > of the integrity hooks in the appropriate places in the fs directory.
> > Collecting, appraising, and storing of file and other types of integrity
> > data is supported. Multiple integrity templates, which implement the
> > integrity API, may register themselves. For now, only a single integrity
> > provider can register itself for the integrity hooks. (Support for multiple
> > providers registering themselves for the integrity hooks would require
> > some form of stacking.)
> >
> > The six integrity hooks are:
> > nameidata_check_integrity, inode_alloc_integrity, inode_free_integrity,
> > bprm_check_integrity, file_free_integrity, file_mmap
> >
> > The five integrity API calls provided are:
> > integrity_must_measure, integrity_collect_measurement,
> > integrity_appraise_measurement, integrity_store_measurement,
> > and integrity_display_template.
> >
> > The type of integrity data being collected, appraised, stored, or
> > displayed is template dependent.
> >
> >
> > ...
> >
> > +int integrity_register_template(const char *template_name,
> > + const struct template_operations *template_ops)
> > +{
> > + int template_len;
> > + struct template_list_entry *entry;
> > +
> > + entry = kzalloc(sizeof(*entry), GFP_KERNEL);
> > + if (!entry)
> > + return -ENOMEM;
> > + INIT_LIST_HEAD(&entry->template);
> > +
> > + atomic_set(&entry->refcount, 1);
> > + template_len = strlen(template_name);
> > + if (template_len > TEMPLATE_NAME_LEN_MAX) {
>
> It would be much neater to perform this check before running kzalloc().
Yes, will be moved in next patch set.
> > + kfree(entry);
> > + return -EINVAL;
> > + }
> > + strcpy(entry->template_name, template_name);
> > + entry->template_ops = template_ops;
> > +
> > + mutex_lock(&integrity_templates_mutex);
> > + list_add_rcu(&entry->template, &integrity_templates);
> > + mutex_unlock(&integrity_templates_mutex);
> > + synchronize_rcu();
> > +
> > + return 0;
> > +}
> > +
> > +EXPORT_SYMBOL_GPL(integrity_register_template);
>
> someone forgot to run checkpatch.
There's a couple of things like this where Lindent "fixes", and then
checkpatch complains. In this case though, Lindent has been fixed. :-)
> >
> > ...
> >
> > +static inline void tget(struct template_list_entry *entry)
> > +{
> > + if (!entry)
> > + return;
> > + atomic_inc(&entry->refcount);
> > +}
> > +
> > +static inline void tput(struct template_list_entry *entry)
> > +{
> > + if (!entry)
> > + return;
> > + if (atomic_dec_and_test(&entry->refcount))
> > + kfree(entry);
> > +}
>
> Do these _really_ need to test for a NULL pointer? It's an extra
> test-n-branch in many fastpaths. It would be better to avoid doing
> this here, if poss.
Cleaned up the callers to avoid requiring the extra test.
Mimi
On Fri, 2008-11-14 at 14:15 -0800, Andrew Morton wrote:
> On Wed, 12 Nov 2008 22:47:13 -0500
> Mimi Zohar <[email protected]> wrote:
>
> > This is a re-release of Integrity Measurement Architecture(IMA) as an
> > independent Linunx Integrity Module(LIM) service provider.
> >
> > As a LIM integrity provider, IMA implements the new LIM must_measure(),
> > collect_measurement(), store_measurement(), and display_template() API
> > calls. The store_measurement() call supports two types of data, IMA
> > (i.e. file data) and generic template data.
> >
> > IMA provides hardware (TPM) based measurement and attestation for both
> > files and other types of template measurements. As the Trusted Computing
> > (TPM) model requires, IMA measures all files before they are accessed
> > in any way (on the bprm_check_integrity, nameidata_check_integrity,
> > file_mmap hooks), and commits the measurements to the TPM. In addition,
> > IMA maintains a list of these hash values, which can be used to validate
> > the aggregate PCR value. The TPM can sign these measurements, and thus
> > the system can prove to itself and to a third party these measurements
> > in a way that cannot be circumvented by malicious or compromised software.
> >
> > When store_measurement() is called for the IMA type of data, the file
> > measurement and the file name hint are used to form an IMA template.
> > IMA then calculates the IMA template measurement(hash) and submits it
> > to the TPM chip for inclusion in one of the chip's Platform Configuration
> > Registers (PCR).
> >
> > When store_measurement() is called for generic template data, IMA
> > calculates the measurement(hash) of the template data, and submits
> > the template measurement to the TPM chip for inclusion in one of the
> > chip's Platform Configuration Registers(PCR).
> >
> > In order to view the contents of template data through securityfs, the
> > template_display() function must be defined in the registered
> > template_operations. In the case of the IMA template, the list of
> > file names and files hashes submitted can be viewed through securityfs.
> >
> > As mentioned above, IMA maintains a list of hash values of executables
> > and other sensitive system files loaded into the run-time of the system.
> > Our work has shown that requests for integrity appraisal and measurement
> > need to be based on knowledge of the filesystem, requiring the system
> > to either be labeled with integrity data or depend on the existent LSM
> > security labels. The previous set of integrity patches modified the LSM
> > modules to be integrity context aware, meaning that the LSM modules made
> > integrity data/metadata appraisal and measurement API calls based on
> > an understanding of the LSM security labels. Both of the LSM maintainers
> > felt that the changes were too intrusive and that integrity enforcement
> > should be made by the integrity provider, not the LSM module.
> >
> > To address these concerns, Stephen Smalley suggested using the
> > security_audit_rule_match(), renamed to security_filter_rule_match(), to
> > define LSM specific integrity measurement policy rules, in lieu of
> > modifying the LSM modules. In the current set of patches, the integrity
> > API calls can be made either by IMA, based on an LSM specific integrity
> > policy, or by an integrity context aware LSM.
> >
> > ...
> >
> > +static void ima_add_boot_aggregate(void)
> > +{
> > + /* cumulative sha1 over tpm registers 0-7 */
> > + struct ima_measure_entry *entry;
> > + size_t count;
> > + int err;
> > +
> > + /* create new entry for boot aggregate */
> > + entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
>
> This uses GFP_ATOMIC, but crypto_alloc_hash() (called later) uses
> GFP_KERNEL.
>
> If this _had_ to be GFP_ATOMIC then you have a bug.
Sorry, thought I fixed this.
> Otherwise, please use the much more reliable GFP_KERNEL here.
On Fri, 2008-11-14 at 14:15 -0800, Andrew Morton wrote:
> On Wed, 12 Nov 2008 22:47:14 -0500
> Mimi Zohar <[email protected]> wrote:
>
> > This version stores integrity information associated with an inode
> > in a radix tree in order to avoid bloating the in memory inode.
> > As entries can not be added to the radix tree at security_initcall,
> > this version removes the dual stage initialization. Allocating and
> > freeing the memory continues to be done at inode_alloc and file_free,
> > respectively, except for inodes created before late_initcall.
> >
> > Signed-off-by: Mimi Zohar <[email protected]>
> > ---
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index bc6460c..0dcdd94 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -683,9 +683,6 @@ struct inode {
> > #ifdef CONFIG_SECURITY
> > void *i_security;
> > #endif
> > -#ifdef CONFIG_INTEGRITY
> > - void *i_integrity;
> > -#endif
>
> ah, I was going to ask about that..
Hm, perhaps posting as a separate patch was not such a good idea.
> > void *i_private; /* fs or device private pointer */
> > };
> >
> > diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
> > index f3aced4..959ae66 100644
> > --- a/security/integrity/ima/Makefile
> > +++ b/security/integrity/ima/Makefile
> > @@ -6,4 +6,4 @@
> > obj-$(CONFIG_IMA) += ima.o
> >
> > ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
> > - ima_policy.o
> > + ima_policy.o ima_iint.o
> > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> > index 9a24305..09a5e1a 100644
> > --- a/security/integrity/ima/ima.h
> > +++ b/security/integrity/ima/ima.h
> > @@ -92,7 +92,6 @@ void ima_store_measurement(void *d);
> > void ima_template_show(struct seq_file *m, void *e,
> > enum integrity_show_type show);
> >
> > -
> > /*
> > * used to protect h_table and sha_table
> > */
> > @@ -109,7 +108,7 @@ extern struct ima_h_table ima_htable;
> >
> > static inline unsigned long IMA_HASH_KEY(u8 *digest)
> > {
> > - return(hash_long(*digest, IMA_HASH_BITS));
> > + return (hash_long(*digest, IMA_HASH_BITS));
>
> And I _did_ ask about that ;)
Definitely better now.
> > }
> >
> > /* TPM "Glue" definitions */
> > @@ -145,11 +144,36 @@ struct ima_iint_cache {
> > u8 hmac[IMA_DIGEST_SIZE];
> > u8 digest[IMA_DIGEST_SIZE];
> > struct mutex mutex;
> > + atomic_t refcount;
> > };
> > #define IMA_IINT_INIT 1
> > #define IMA_MUST_MEASURE 2
> > #define IMA_MEASURED 4
> >
> > +void ima_iint_init(void);
> > +struct ima_iint_cache * ima_iint_lookup(struct inode *inode);
>
> checkpatch...
> >
> > ...
> >
> > --- /dev/null
> > +++ b/security/integrity/ima/ima_iint.c
> > @@ -0,0 +1,68 @@
> > +/*
> > + * Copyright (C) 2008 IBM Corporation
> > + *
> > + * Authors:
> > + * Mimi Zohar <[email protected]>
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation, version 2 of the
> > + * License.
> > + *
> > + * File: ima_iint.c
> > + * cache integrity information associated with an inode
> > + * using a radix tree.
> > + */
> > +#include <linux/module.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/radix-tree.h>
> > +#include "ima.h"
> > +
> > +static struct radix_tree_root ima_iint_store;
> > +DEFINE_SPINLOCK(ima_iint_lock);
> > +
> > +void ima_iint_init(void)
> > +{
> > + INIT_RADIX_TREE(&ima_iint_store, GFP_ATOMIC);
> > +}
>
> Use the RADIX_TREE() macro, then remove this function.
Done. Will be in next patch set.
Mimi
On Mon, 2008-11-17 at 11:05 -0500, Christoph Hellwig wrote:
> On Wed, Nov 12, 2008 at 10:47:12PM -0500, Mimi Zohar wrote:
> > This version resolves the merge issues resulting from the removal
> > of the nameidata parameter to inode_permission(), by moving the
> > integrity_inode_permission() call from inode_permission() to
> > may_open(), and renaming the hook to integrity_nameidata_check().
>
> Still neither a good parameter nor a good name. If you look at fsdevel
> you'll see that a patch for the next merged window is already out and
> in Al's to be applied queue that removes the nameidata there. A
> strcut path and maybe the MAY_ lookup flags should be enough for you,
> and a integrity_path_check also sounds like it really does what you
> want.
Ok. So, instead of integrity_nameidata_check(nd, flags), call it
integrity_path_check(path, flags).
Perhaps I'm looking at the wrong vfs tree, but I don't see the changes.
Where is fsdevel?
> Also please merge the last radix tree patch into this one so tat it's
> possible to review the code that actually goes in instead of replacing
> a large part of it in a follow-up patch.
np
Mimi
On Fri, 2008-11-14 at 14:18 -0800, Andrew Morton wrote:
> On Wed, 12 Nov 2008 22:47:10 -0500
> Mimi Zohar <[email protected]> wrote:
>
> > The Linux Integrity Module (LIM) Framework provides hooks
> > ...
> This all looks quite mergeable to me, although I am far from being an
> expert on security things.
>
> One thing which I cannot say, and which is quite important: how useful
> will all of this be to our users? Are people asking for it? Are
> people likely to enable and use it? Are they even likely to understand
> it? ;) Are any large/important customers asking for it? Are distros
> likely to enable and support it?
LIM/IMA's maintenance of a TPM hardware anchored file measurement
list is fundamental to the Trusted Computing Group's standards
efforts. Several projects have implemented the TNC (Trusted Network
Connect) and PTS (Platform Trust Services) standards (see below).
There are three demo packaged distros which have integrated these
apps, two of which are government funded (EU and US), with definite
customer interest. We are working with the RHEL team to provide
a supported, patched kernel for HAP. All of these so far have used
the old LSM based IMA, and have asked for a supported, upstreamed
implementation, with the ability to work with SELinux.
Standards
http://www.trustedcomputinggroup.org
TNC/PTS Projects:
http://tnc.inform.fh-hannover.de/wiki/index.php/Main_Page (server)
http://sourceforge.net/projects/libtnc (library)
http://hostap.epitest.fi/wpa_supplicant/wpa_supplicant (client)
http://sourceforge.jp/projects/openpts (client and server)
Test Distros:
http://unit.aist.go.jp/itri/knoppix/index-en.html (trusted Knoppix)
http://www.nsa.gov/ia/industry/HAP/ (US)
http://www.opentc.net (EU)
On Mon, Nov 17, 2008 at 02:09:40PM -0500, Mimi Zohar wrote:
> Ok. So, instead of integrity_nameidata_check(nd, flags), call it
> integrity_path_check(path, flags).
Yeah.
> Perhaps I'm looking at the wrong vfs tree, but I don't see the changes.
> Where is fsdevel?
linux-fsdevel@vger. But the patch actually went to lkml,
"[PATCH] pass a struct path * to may_open". Note that the plan is to
reduce availability of strut nameidata to a minimum outside of the core
path lookup functionality - so relying on it is not a good idea.
On Fri, 14 Nov 2008, Andrew Morton wrote:
> One thing which I cannot say, and which is quite important: how useful
> will all of this be to our users? Are people asking for it?
Apparently, some government users are, and there's a DoD decree which
requires new equipment to include TPM hardware where possible:
http://iase.disa.mil/policy-guidance/dod-dar-tpm-decree07-03-07.pdf
This is to support encryption of data at rest, and for "device
authentication" (requiring remote attestation of system integrity).
It's not clear to me yet how compelling this will be for general-case
users.
> Are
> people likely to enable and use it? Are they even likely to understand
> it? ;) Are any large/important customers asking for it? Are distros
> likely to enable and support it?
I believe that TPM is in "tech preview" in RHEL 5.2, and that there is a
desire to integrate it more fully with the OS via TCG software such as
Trousers: http://trousers.sourceforge.net/
- James
--
James Morris
<[email protected]>