* [PATCH v2 01/14] integrity: move ima inode integrity data management
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 02/14] xattr: define vfs_getxattr_alloc and vfs_xattr_cmp Mimi Zohar
` (12 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Move the inode integrity data(iint) management up to the
integrity layer in order to share the integrity data area
among the different integrity models.
Changelog:
- Define integrity_iint_store/lock as static
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
include/linux/ima.h | 12 ---
include/linux/integrity.h | 28 +++++++
security/Kconfig | 2 +-
security/Makefile | 4 +-
security/integrity/Kconfig | 6 ++
security/integrity/Makefile | 10 +++
security/integrity/iint.c | 150 +++++++++++++++++++++++++++++++++++++
security/integrity/ima/Kconfig | 1 +
security/integrity/ima/Makefile | 2 +-
security/integrity/ima/ima.h | 34 +++------
security/integrity/ima/ima_api.c | 9 +-
security/integrity/ima/ima_iint.c | 146 ------------------------------------
security/integrity/ima/ima_main.c | 21 +++---
security/integrity/integrity.h | 42 ++++++++++
security/security.c | 5 +-
15 files changed, 270 insertions(+), 202 deletions(-)
create mode 100644 include/linux/integrity.h
create mode 100644 security/integrity/Kconfig
create mode 100644 security/integrity/Makefile
create mode 100644 security/integrity/iint.c
delete mode 100644 security/integrity/ima/ima_iint.c
create mode 100644 security/integrity/integrity.h
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 975837e..4dce900 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -15,8 +15,6 @@ struct linux_binprm;
#ifdef CONFIG_IMA
extern int ima_bprm_check(struct linux_binprm *bprm);
-extern int ima_inode_alloc(struct inode *inode);
-extern void ima_inode_free(struct inode *inode);
extern int ima_file_check(struct file *file, int mask);
extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
@@ -28,16 +26,6 @@ static inline int ima_bprm_check(struct linux_binprm *bprm)
return 0;
}
-static inline int ima_inode_alloc(struct inode *inode)
-{
- return 0;
-}
-
-static inline void ima_inode_free(struct inode *inode)
-{
- return;
-}
-
static inline int ima_file_check(struct file *file, int mask)
{
return 0;
diff --git a/include/linux/integrity.h b/include/linux/integrity.h
new file mode 100644
index 0000000..276081f
--- /dev/null
+++ b/include/linux/integrity.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2009 IBM Corporation
+ * Author: Mimi Zohar <zohar@us.ibm.com>
+ *
+ * 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
+
+#ifdef CONFIG_INTEGRITY
+extern int integrity_inode_alloc(struct inode *inode);
+extern void integrity_inode_free(struct inode *inode);
+
+#else
+static inline int integrity_inode_alloc(struct inode *inode)
+{
+ return 0;
+}
+
+static inline void integrity_inode_free(struct inode *inode)
+{
+ return;
+}
+#endif /* CONFIG_INTEGRITY_H */
+#endif /* _LINUX_INTEGRITY_H */
diff --git a/security/Kconfig b/security/Kconfig
index 0e3a5ac..7e7b0f9 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -142,7 +142,7 @@ source security/smack/Kconfig
source security/tomoyo/Kconfig
source security/yama/Kconfig
-source security/integrity/ima/Kconfig
+source security/integrity/Kconfig
choice
prompt "Default security module"
diff --git a/security/Makefile b/security/Makefile
index 04354d1..32cc754 100644
--- a/security/Makefile
+++ b/security/Makefile
@@ -24,5 +24,5 @@ obj-$(CONFIG_SECURITY_YAMA) += yama/built-in.o
obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o
# Object integrity file lists
-subdir-$(CONFIG_IMA) += integrity/ima
-obj-$(CONFIG_IMA) += integrity/ima/built-in.o
+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..2704691
--- /dev/null
+++ b/security/integrity/Kconfig
@@ -0,0 +1,6 @@
+#
+config INTEGRITY
+ def_bool y
+ depends on IMA
+
+source security/integrity/ima/Kconfig
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
new file mode 100644
index 0000000..6eddd61
--- /dev/null
+++ b/security/integrity/Makefile
@@ -0,0 +1,10 @@
+#
+# Makefile for caching inode integrity data (iint)
+#
+
+obj-$(CONFIG_INTEGRITY) += integrity.o
+
+integrity-y := iint.o
+
+subdir-$(CONFIG_IMA) += ima
+obj-$(CONFIG_IMA) += ima/built-in.o
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
new file mode 100644
index 0000000..e72c966
--- /dev/null
+++ b/security/integrity/iint.c
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2008-2010 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * 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: iint.c
+ * - implements the integrity hooks: integrity_inode_alloc,
+ * integrity_inode_free
+ * - cache integrity information associated with an inode
+ * using a radix tree.
+ */
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/fs.h>
+#include <linux/radix-tree.h>
+#include "integrity.h"
+
+static RADIX_TREE(integrity_iint_store, GFP_ATOMIC);
+static DEFINE_SPINLOCK(integrity_iint_lock);
+
+static struct kmem_cache *iint_cache __read_mostly;
+
+/* integrity_iint_find_get - return the iint associated with an inode
+ *
+ * integrity_iint_find_get gets a reference to the iint. Caller must
+ * remember to put the iint reference.
+ */
+struct integrity_iint_cache *integrity_iint_find_get(struct inode *inode)
+{
+ struct integrity_iint_cache *iint;
+
+ rcu_read_lock();
+ iint = radix_tree_lookup(&integrity_iint_store, (unsigned long)inode);
+ if (!iint)
+ goto out;
+ kref_get(&iint->refcount);
+out:
+ rcu_read_unlock();
+ return iint;
+}
+
+/**
+ * integrity_inode_alloc - allocate an iint associated with an inode
+ * @inode: pointer to the inode
+ */
+int integrity_inode_alloc(struct inode *inode)
+{
+ struct integrity_iint_cache *iint = NULL;
+ int rc = 0;
+
+ iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
+ if (!iint)
+ return -ENOMEM;
+
+ rc = radix_tree_preload(GFP_NOFS);
+ if (rc < 0)
+ goto out;
+
+ spin_lock(&integrity_iint_lock);
+ rc = radix_tree_insert(&integrity_iint_store, (unsigned long)inode,
+ iint);
+ spin_unlock(&integrity_iint_lock);
+ radix_tree_preload_end();
+out:
+ if (rc < 0)
+ kmem_cache_free(iint_cache, iint);
+
+ return rc;
+}
+
+/* iint_free - called when the iint refcount goes to zero */
+void iint_free(struct kref *kref)
+{
+ struct integrity_iint_cache *iint =
+ container_of(kref, struct integrity_iint_cache, refcount);
+ iint->version = 0;
+ iint->flags = 0UL;
+ if (iint->readcount != 0) {
+ printk(KERN_INFO "%s: readcount: %ld\n", __func__,
+ iint->readcount);
+ iint->readcount = 0;
+ }
+ if (iint->writecount != 0) {
+ printk(KERN_INFO "%s: writecount: %ld\n", __func__,
+ iint->writecount);
+ iint->writecount = 0;
+ }
+ if (iint->opencount != 0) {
+ printk(KERN_INFO "%s: opencount: %ld\n", __func__,
+ iint->opencount);
+ iint->opencount = 0;
+ }
+ kref_init(&iint->refcount);
+ kmem_cache_free(iint_cache, iint);
+}
+
+void iint_rcu_free(struct rcu_head *rcu_head)
+{
+ struct integrity_iint_cache *iint =
+ container_of(rcu_head, struct integrity_iint_cache, rcu);
+ kref_put(&iint->refcount, iint_free);
+}
+
+/**
+ * integrity_inode_free - called on security_inode_free
+ * @inode: pointer to the inode
+ *
+ * Free the integrity information(iint) associated with an inode.
+ */
+void integrity_inode_free(struct inode *inode)
+{
+ struct integrity_iint_cache *iint;
+
+ spin_lock(&integrity_iint_lock);
+ iint = radix_tree_delete(&integrity_iint_store, (unsigned long)inode);
+ spin_unlock(&integrity_iint_lock);
+ if (iint)
+ call_rcu(&iint->rcu, iint_rcu_free);
+}
+
+static void init_once(void *foo)
+{
+ struct integrity_iint_cache *iint = foo;
+
+ memset(iint, 0, sizeof *iint);
+ iint->version = 0;
+ iint->flags = 0UL;
+ mutex_init(&iint->mutex);
+ iint->readcount = 0;
+ iint->writecount = 0;
+ iint->opencount = 0;
+ kref_init(&iint->refcount);
+}
+
+static int __init integrity_iintcache_init(void)
+{
+ iint_cache =
+ kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
+ 0, SLAB_PANIC, init_once);
+ return 0;
+}
+
+security_initcall(integrity_iintcache_init);
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index b6ecfd4..19c053b 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -3,6 +3,7 @@
config IMA
bool "Integrity Measurement Architecture(IMA)"
depends on SECURITY
+ select INTEGRITY
select SECURITYFS
select CRYPTO
select CRYPTO_HMAC
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 787c4cb..5690c02 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_iint.o ima_audit.o
+ ima_policy.o ima_audit.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 16d100d..a58ac9f 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -24,11 +24,13 @@
#include <linux/tpm.h>
#include <linux/audit.h>
+#include "../integrity.h"
+
enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
/* digest size for IMA, fits SHA1 or MD5 */
-#define IMA_DIGEST_SIZE 20
+#define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE
#define IMA_EVENT_NAME_LEN_MAX 255
#define IMA_HASH_BITS 9
@@ -94,38 +96,22 @@ static inline unsigned long ima_hash_key(u8 *digest)
return hash_long(*digest, IMA_HASH_BITS);
}
-/* iint cache flags */
-#define IMA_MEASURED 1
-
-/* integrity data associated with an inode */
-struct ima_iint_cache {
- u64 version; /* track inode changes */
- unsigned long flags;
- u8 digest[IMA_DIGEST_SIZE];
- struct mutex mutex; /* protects: version, flags, digest */
- long readcount; /* measured files readcount */
- long writecount; /* measured files writecount */
- long opencount; /* opens reference count */
- struct kref refcount; /* ima_iint_cache reference count */
- struct rcu_head rcu;
-};
-
/* LIM API function definitions */
-int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
+int ima_must_measure(struct integrity_iint_cache *iint, struct inode *inode,
int mask, int function);
-int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
-void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
+int ima_collect_measurement(struct integrity_iint_cache *iint,
+ struct file *file);
+void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
const unsigned char *filename);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode);
-void ima_template_show(struct seq_file *m, void *e,
- enum ima_show_type show);
+void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show);
/* radix tree calls to lookup, insert, delete
* integrity data associated with an inode.
*/
-struct ima_iint_cache *ima_iint_insert(struct inode *inode);
-struct ima_iint_cache *ima_iint_find_get(struct inode *inode);
+struct integrity_iint_cache *ima_iint_insert(struct inode *inode);
+struct integrity_iint_cache *ima_iint_find_get(struct inode *inode);
void iint_free(struct kref *kref);
void iint_rcu_free(struct rcu_head *rcu);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 52015d0..42adfd4 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -111,7 +111,7 @@ err_out:
* For matching a DONT_MEASURE policy, no policy, or other
* error, return an error code.
*/
-int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
+int ima_must_measure(struct integrity_iint_cache *iint, struct inode *inode,
int mask, int function)
{
int must_measure;
@@ -133,7 +133,8 @@ int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
*
* Return 0 on success, error code otherwise
*/
-int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file)
+int ima_collect_measurement(struct integrity_iint_cache *iint,
+ struct file *file)
{
int result = -EEXIST;
@@ -163,8 +164,8 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file)
*
* Must be called with iint->mutex held.
*/
-void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
- const unsigned char *filename)
+void ima_store_measurement(struct integrity_iint_cache *iint,
+ struct file *file, const unsigned char *filename)
{
const char *op = "add_template_measure";
const char *audit_cause = "ENOMEM";
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
deleted file mode 100644
index 7625b85..0000000
--- a/security/integrity/ima/ima_iint.c
+++ /dev/null
@@ -1,146 +0,0 @@
-/*
- * Copyright (C) 2008 IBM Corporation
- *
- * Authors:
- * Mimi Zohar <zohar@us.ibm.com>
- *
- * 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
- * - implements the IMA hooks: ima_inode_alloc, ima_inode_free
- * - cache integrity information associated with an inode
- * using a radix tree.
- */
-#include <linux/slab.h>
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/radix-tree.h>
-#include "ima.h"
-
-RADIX_TREE(ima_iint_store, GFP_ATOMIC);
-DEFINE_SPINLOCK(ima_iint_lock);
-
-static struct kmem_cache *iint_cache __read_mostly;
-
-/* ima_iint_find_get - return the iint associated with an inode
- *
- * ima_iint_find_get gets a reference to the iint. Caller must
- * remember to put the iint reference.
- */
-struct ima_iint_cache *ima_iint_find_get(struct inode *inode)
-{
- struct ima_iint_cache *iint;
-
- rcu_read_lock();
- iint = radix_tree_lookup(&ima_iint_store, (unsigned long)inode);
- if (!iint)
- goto out;
- kref_get(&iint->refcount);
-out:
- rcu_read_unlock();
- return iint;
-}
-
-/**
- * ima_inode_alloc - allocate an iint associated with an inode
- * @inode: pointer to the inode
- */
-int ima_inode_alloc(struct inode *inode)
-{
- struct ima_iint_cache *iint = NULL;
- int rc = 0;
-
- iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
- if (!iint)
- return -ENOMEM;
-
- rc = radix_tree_preload(GFP_NOFS);
- if (rc < 0)
- goto out;
-
- 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();
-out:
- if (rc < 0)
- kmem_cache_free(iint_cache, iint);
-
- return rc;
-}
-
-/* iint_free - called when the iint refcount goes to zero */
-void iint_free(struct kref *kref)
-{
- struct ima_iint_cache *iint = container_of(kref, struct ima_iint_cache,
- refcount);
- iint->version = 0;
- iint->flags = 0UL;
- if (iint->readcount != 0) {
- printk(KERN_INFO "%s: readcount: %ld\n", __func__,
- iint->readcount);
- iint->readcount = 0;
- }
- if (iint->writecount != 0) {
- printk(KERN_INFO "%s: writecount: %ld\n", __func__,
- iint->writecount);
- iint->writecount = 0;
- }
- if (iint->opencount != 0) {
- printk(KERN_INFO "%s: opencount: %ld\n", __func__,
- iint->opencount);
- iint->opencount = 0;
- }
- kref_init(&iint->refcount);
- kmem_cache_free(iint_cache, iint);
-}
-
-void iint_rcu_free(struct rcu_head *rcu_head)
-{
- struct ima_iint_cache *iint = container_of(rcu_head,
- struct ima_iint_cache, rcu);
- kref_put(&iint->refcount, iint_free);
-}
-
-/**
- * ima_inode_free - called on security_inode_free
- * @inode: pointer to the inode
- *
- * Free the integrity information(iint) associated with an inode.
- */
-void ima_inode_free(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);
- if (iint)
- call_rcu(&iint->rcu, iint_rcu_free);
-}
-
-static void init_once(void *foo)
-{
- struct ima_iint_cache *iint = foo;
-
- memset(iint, 0, sizeof *iint);
- iint->version = 0;
- iint->flags = 0UL;
- mutex_init(&iint->mutex);
- iint->readcount = 0;
- iint->writecount = 0;
- iint->opencount = 0;
- kref_init(&iint->refcount);
-}
-
-static int __init ima_iintcache_init(void)
-{
- iint_cache =
- kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
- SLAB_PANIC, init_once);
- return 0;
-}
-security_initcall(ima_iintcache_init);
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f936413..8c231f3 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -18,6 +18,7 @@
*/
#include <linux/module.h>
#include <linux/file.h>
+#include <linux/fs.h>
#include <linux/binfmts.h>
#include <linux/mount.h>
#include <linux/mman.h>
@@ -97,7 +98,7 @@ out:
*/
enum iint_pcr_error { TOMTOU, OPEN_WRITERS };
static void ima_read_write_check(enum iint_pcr_error error,
- struct ima_iint_cache *iint,
+ struct integrity_iint_cache *iint,
struct inode *inode,
const unsigned char *filename)
{
@@ -118,7 +119,7 @@ static void ima_read_write_check(enum iint_pcr_error error,
/*
* Update the counts given an fmode_t
*/
-static void ima_inc_counts(struct ima_iint_cache *iint, fmode_t mode)
+static void ima_inc_counts(struct integrity_iint_cache *iint, fmode_t mode)
{
BUG_ON(!mutex_is_locked(&iint->mutex));
@@ -145,12 +146,12 @@ void ima_counts_get(struct file *file)
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
fmode_t mode = file->f_mode;
- struct ima_iint_cache *iint;
+ struct integrity_iint_cache *iint;
int rc;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return;
- iint = ima_iint_find_get(inode);
+ iint = integrity_iint_find_get(inode);
if (!iint)
return;
mutex_lock(&iint->mutex);
@@ -173,8 +174,8 @@ out:
/*
* Decrement ima counts
*/
-static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode,
- struct file *file)
+static void ima_dec_counts(struct integrity_iint_cache *iint,
+ struct inode *inode, struct file *file)
{
mode_t mode = file->f_mode;
BUG_ON(!mutex_is_locked(&iint->mutex));
@@ -211,11 +212,11 @@ static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode,
void ima_file_free(struct file *file)
{
struct inode *inode = file->f_dentry->d_inode;
- struct ima_iint_cache *iint;
+ struct integrity_iint_cache *iint;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return;
- iint = ima_iint_find_get(inode);
+ iint = integrity_iint_find_get(inode);
if (!iint)
return;
@@ -229,12 +230,12 @@ static int process_measurement(struct file *file, const unsigned char *filename,
int mask, int function)
{
struct inode *inode = file->f_dentry->d_inode;
- struct ima_iint_cache *iint;
+ struct integrity_iint_cache *iint;
int rc;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
- iint = ima_iint_find_get(inode);
+ iint = integrity_iint_find_get(inode);
if (!iint)
return -ENOMEM;
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
new file mode 100644
index 0000000..f1013c9
--- /dev/null
+++ b/security/integrity/integrity.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2009-2010 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * 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.h
+ */
+#include <linux/types.h>
+#include <linux/integrity.h>
+#include <crypto/sha.h>
+
+#define MAX_DIGEST_SIZE SHA1_DIGEST_SIZE
+
+/* iint cache flags */
+#define IMA_MEASURED 1
+
+/* integrity data associated with an inode */
+struct integrity_iint_cache {
+ u64 version; /* track inode changes */
+ unsigned long flags;
+ u8 digest[MAX_DIGEST_SIZE];
+ struct mutex mutex; /* protects: version, flags, digest */
+ long readcount; /* measured files readcount */
+ long writecount; /* measured files writecount */
+ long opencount; /* opens reference count */
+ struct kref refcount; /* ima_iint_cache reference count */
+ struct rcu_head rcu;
+};
+
+/* radix tree calls to lookup, insert, delete
+ * integrity data associated with an inode.
+ */
+struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
+struct integrity_iint_cache *integrity_iint_find_get(struct inode *inode);
+void iint_free(struct kref *kref);
+void iint_rcu_free(struct rcu_head *rcu);
diff --git a/security/security.c b/security/security.c
index e8c87b8..36a0de3 100644
--- a/security/security.c
+++ b/security/security.c
@@ -16,6 +16,7 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/security.h>
+#include <linux/integrity.h>
#include <linux/ima.h>
/* Boot-time LSM user choice */
@@ -339,7 +340,7 @@ int security_inode_alloc(struct inode *inode)
ret = security_ops->inode_alloc_security(inode);
if (ret)
return ret;
- ret = ima_inode_alloc(inode);
+ ret = integrity_inode_alloc(inode);
if (ret)
security_inode_free(inode);
return ret;
@@ -347,7 +348,7 @@ int security_inode_alloc(struct inode *inode)
void security_inode_free(struct inode *inode)
{
- ima_inode_free(inode);
+ integrity_inode_free(inode);
security_ops->inode_free_security(inode);
}
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 02/14] xattr: define vfs_getxattr_alloc and vfs_xattr_cmp
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 01/14] integrity: move ima inode integrity data management Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 03/14] evm: re-release Mimi Zohar
` (11 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
vfs_getxattr_alloc() and vfs_xattr_cmp() are two new kernel xattr
helper functions. vfs_getxattr_alloc() first allocates memory for
the requested xattr and then retrieves it. vfs_xattr_cmp() compares
a given value with the contents of an extended attribute.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
---
fs/xattr.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/xattr.h | 5 +++-
2 files changed, 62 insertions(+), 1 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 01bb813..e1f6b8b 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -159,6 +159,64 @@ out_noalloc:
}
EXPORT_SYMBOL_GPL(xattr_getsecurity);
+/*
+ * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr
+ *
+ * Allocate memory, if not already allocated, or re-allocate correct size,
+ * before retrieving the extended attribute.
+ *
+ * Returns the result of alloc, if failed, or the getxattr operation.
+ */
+ssize_t
+vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value,
+ size_t xattr_size, gfp_t flags)
+{
+ struct inode *inode = dentry->d_inode;
+ char *value = *xattr_value;
+ int error;
+
+ error = xattr_permission(inode, name, MAY_READ);
+ if (error)
+ return error;
+
+ if (!inode->i_op->getxattr)
+ return -EOPNOTSUPP;
+
+ error = inode->i_op->getxattr(dentry, name, NULL, 0);
+ if (error < 0)
+ return error;
+
+ if (!value || (error > xattr_size)) {
+ value = krealloc(*xattr_value, error + 1, flags);
+ if (!value)
+ return -ENOMEM;
+ memset(value, 0, error + 1);
+ }
+
+ error = inode->i_op->getxattr(dentry, name, value, error);
+ *xattr_value = value;
+ return error;
+}
+
+/* Compare an extended attribute value with the given value */
+int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
+ const char *value, size_t size, gfp_t flags)
+{
+ char *xattr_value = NULL;
+ int rc;
+
+ rc = vfs_getxattr_alloc(dentry, xattr_name, &xattr_value, 0, flags);
+ if (rc < 0)
+ return rc;
+
+ if ((rc != size) || (memcmp(xattr_value, value, rc) != 0))
+ rc = -EINVAL;
+ else
+ rc = 0;
+ kfree(xattr_value);
+ return rc;
+}
+
ssize_t
vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
{
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index f1e5bde..9a0b09c 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -72,7 +72,10 @@ ssize_t generic_getxattr(struct dentry *dentry, const char *name, void *buffer,
ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
int generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
int generic_removexattr(struct dentry *dentry, const char *name);
-
+ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
+ char **xattr_value, size_t size, gfp_t flags);
+int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
+ const char *value, size_t size, gfp_t flags);
#endif /* __KERNEL__ */
#endif /* _LINUX_XATTR_H */
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 03/14] evm: re-release
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 01/14] integrity: move ima inode integrity data management Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 02/14] xattr: define vfs_getxattr_alloc and vfs_xattr_cmp Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 04/14] ima: move ima_file_free before releasing the file Mimi Zohar
` (10 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
EVM protects a file's security extended attributes against integrity
attacks. It maintains an HMAC-sha1 value across the extended attributes,
storing the value as the extended attribute 'security.evm'. EVM has gone
through a number of iterations, initially as an LSM module, subsequently
as a LIM integrity provider, and now, when co-located with a security_
hook, embedded directly in the security_ hook, similar to IMA.
This is the first part of a local file integrity verification system.
While this part does authenticate the selected extended attributes, and
cryptographically bind them to the inode, coming extensions will bind
other directory and inode metadata for more complete protection. The
set of protected security extended attributes is configured at compile.
EVM depends on the Kernel Key Retention System to provide it with a key
for the HMAC-sha1 operation. The key is loaded onto the root's keyring,
typically by 'readevmkey', which prompts for a password from the console.
(Future work will define new key-types for use with TPM sealed keys and
encrypted symmetric keys, so that on systems with a TPM, the EVM key will
never be visible outside the kernel in plaintext form.) To signal EVM,
that the key has been loaded onto the keyring, 'echo 1 > <securityfs>/evm'.
This is normally done in the initrd, which has already been measured as
part of the trusted boot. (Refer to http://linux-ima.sourceforge.net/#EVM.)
EVM adds the following three calls to the existing security hooks:
evm_inode_setxattr(), evm_inode_post_setxattr(), and evm_inode_removexattr.
To initialize and update the 'security.evm' extended attribute, EVM
defines three calls: evm_inode_post_init(), evm_inode_post_setattr() and
evm_inode_post_removexattr() hooks.
To verify the integrity of an extended attribute, EVM exports
evm_verifyxattr().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
---
Documentation/ABI/testing/evm | 22 +++
include/linux/integrity.h | 7 +
include/linux/xattr.h | 3 +
security/integrity/Kconfig | 3 +-
security/integrity/Makefile | 2 +
security/integrity/evm/Kconfig | 13 ++
security/integrity/evm/Makefile | 6 +
security/integrity/evm/evm.h | 35 ++++
security/integrity/evm/evm_crypto.c | 179 +++++++++++++++++++++
security/integrity/evm/evm_main.c | 296 +++++++++++++++++++++++++++++++++++
security/integrity/evm/evm_secfs.c | 108 +++++++++++++
security/integrity/iint.c | 2 +
security/integrity/integrity.h | 3 +
13 files changed, 678 insertions(+), 1 deletions(-)
create mode 100644 Documentation/ABI/testing/evm
create mode 100644 security/integrity/evm/Kconfig
create mode 100644 security/integrity/evm/Makefile
create mode 100644 security/integrity/evm/evm.h
create mode 100644 security/integrity/evm/evm_crypto.c
create mode 100644 security/integrity/evm/evm_main.c
create mode 100644 security/integrity/evm/evm_secfs.c
diff --git a/Documentation/ABI/testing/evm b/Documentation/ABI/testing/evm
new file mode 100644
index 0000000..dc3f153
--- /dev/null
+++ b/Documentation/ABI/testing/evm
@@ -0,0 +1,22 @@
+What: security/evm
+Date: July 2010
+Contact: Mimi Zohar <zohar@us.ibm.com>
+Description:
+ EVM protects a file's security extended attributes against
+ integrity attacks. It maintains an HMAC-sha1 value across
+ the extended attributes, storing the value as the extended
+ attribute 'security.evm'.
+
+ As EVM depends on the Kernel Key Retention System to provide
+ it with a key for the HMAC-sha1 operation, EVM needs to wait
+ until the key is loaded onto the root's keyring, typically
+ by 'readevmkey', which prompts for a password from the console.
+ (Future work will define new key-types for use with TPM sealed
+ keys and encrypted symmetric keys, so that on systems with a
+ TPM, the EVM key will never be visible outside the kernel in
+ plaintext form.)
+
+ To signal EVM, that the key has been loaded onto the keyring,
+ 'echo 1 > <securityfs>/evm'. This is normally done in the
+ initrd, which is part of the trusted boot.
+ (Refer to http://linux-ima.sourceforge.net/#EVM.)
diff --git a/include/linux/integrity.h b/include/linux/integrity.h
index 276081f..fa9c199 100644
--- a/include/linux/integrity.h
+++ b/include/linux/integrity.h
@@ -10,6 +10,13 @@
#ifndef _LINUX_INTEGRITY_H
#define _LINUX_INTEGRITY_H
+enum integrity_status {
+ INTEGRITY_PASS = 0,
+ INTEGRITY_FAIL,
+ INTEGRITY_NOLABEL,
+ INTEGRITY_UNKNOWN,
+};
+
#ifdef CONFIG_INTEGRITY
extern int integrity_inode_alloc(struct inode *inode);
extern void integrity_inode_free(struct inode *inode);
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 9a0b09c..4c35d84 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -34,6 +34,9 @@
#define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)
/* Security namespace */
+#define XATTR_EVM_SUFFIX "evm"
+#define XATTR_NAME_EVM XATTR_SECURITY_PREFIX XATTR_EVM_SUFFIX
+
#define XATTR_SELINUX_SUFFIX "selinux"
#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 2704691..4bf00ac 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -1,6 +1,7 @@
#
config INTEGRITY
def_bool y
- depends on IMA
+ depends on IMA || EVM
source security/integrity/ima/Kconfig
+source security/integrity/evm/Kconfig
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index 6eddd61..0ae44ae 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -8,3 +8,5 @@ integrity-y := iint.o
subdir-$(CONFIG_IMA) += ima
obj-$(CONFIG_IMA) += ima/built-in.o
+subdir-$(CONFIG_EVM) += evm
+obj-$(CONFIG_EVM) += evm/built-in.o
diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig
new file mode 100644
index 0000000..8a546f7
--- /dev/null
+++ b/security/integrity/evm/Kconfig
@@ -0,0 +1,13 @@
+config EVM
+ boolean "EVM support"
+ depends on SECURITY && KEYS
+ select CRYPTO_HMAC
+ select CRYPTO_MD5
+ select CRYPTO_SHA1
+ default n
+ help
+ A configurable set of security extended attributes are HMAC
+ protected against modification using the TPM's kernel root key,
+ if configured, or with a pass-phrase.
+
+ If you are unsure how to answer this question, answer N.
diff --git a/security/integrity/evm/Makefile b/security/integrity/evm/Makefile
new file mode 100644
index 0000000..0787d26
--- /dev/null
+++ b/security/integrity/evm/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for building the Extended Verification Module(EVM)
+#
+obj-$(CONFIG_EVM) += evm.o
+
+evm-y := evm_main.o evm_crypto.o evm_secfs.o
diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
new file mode 100644
index 0000000..0b6f7b2
--- /dev/null
+++ b/security/integrity/evm/evm.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2005-2010 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * 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: evm.h
+ *
+ */
+#include <linux/security.h>
+#include "../integrity.h"
+
+extern int evm_initialized;
+extern char *evm_hmac;
+extern int evm_hmac_size;
+
+/* List of EVM protected security xattrs */
+extern char *evm_config_xattrnames[];
+
+extern int evm_init_tpmkernkey(void);
+extern int evm_update_evmxattr(struct dentry *dentry,
+ const char *req_xattr_name,
+ const char *req_xattr_value,
+ size_t req_xattr_value_len,
+ struct integrity_iint_cache *iint);
+extern int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
+ const char *req_xattr_value,
+ size_t req_xattr_value_len, char *digest);
+extern int evm_init_secfs(void);
+extern void evm_cleanup_secfs(void);
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
new file mode 100644
index 0000000..4f1be71
--- /dev/null
+++ b/security/integrity/evm/evm_crypto.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2005-2010 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * 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: evm_crypto.c
+ * Using root's kernel master key (kmk), calculate the HMAC
+ */
+
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/xattr.h>
+#include <keys/user-type.h>
+#include <linux/scatterlist.h>
+#include "evm.h"
+
+#define TPMKEY "evm_key"
+#define MAX_TPMKEY 128
+static unsigned char tpm_key[MAX_TPMKEY];
+static int tpm_keylen = MAX_TPMKEY;
+
+static int init_desc(struct hash_desc *desc)
+{
+ int rc;
+
+ desc->tfm = crypto_alloc_hash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(desc->tfm)) {
+ pr_info("Can not allocate %s (reason: %ld)\n",
+ evm_hmac, PTR_ERR(desc->tfm));
+ rc = PTR_ERR(desc->tfm);
+ return rc;
+ }
+ desc->flags = 0;
+ crypto_hash_setkey(desc->tfm, tpm_key, tpm_keylen);
+ rc = crypto_hash_init(desc);
+ if (rc)
+ crypto_free_hash(desc->tfm);
+ return rc;
+}
+
+/* Protect against 'cutting & pasting' security.evm xattr, include inode
+ * specific info.
+ *
+ * (Additional directory/file metadata needs to be added for more complete
+ * protection.)
+ */
+static void hmac_add_misc(struct hash_desc *desc, struct inode *inode,
+ char *digest)
+{
+ struct h_misc {
+ unsigned long ino;
+ __u32 generation;
+ uid_t uid;
+ gid_t gid;
+ umode_t mode;
+ } hmac_misc;
+ struct scatterlist sg[1];
+
+ memset(&hmac_misc, 0, sizeof hmac_misc);
+ hmac_misc.ino = inode->i_ino;
+ hmac_misc.generation = inode->i_generation;
+ hmac_misc.uid = inode->i_uid;
+ hmac_misc.gid = inode->i_gid;
+ hmac_misc.mode = inode->i_mode;
+ sg_init_one(sg, &hmac_misc, sizeof hmac_misc);
+ crypto_hash_update(desc, sg, sizeof hmac_misc);
+ crypto_hash_final(desc, digest);
+}
+
+/*
+ * Calculate the HMAC value across the set of protected security xattrs.
+ *
+ * Instead of retrieving the requested xattr, for performance, calculate
+ * the hmac using the requested xattr value. Don't alloc/free memory for
+ * each xattr, but attempt to re-use the previously allocated memory.
+ */
+int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
+ const char *req_xattr_value, size_t req_xattr_value_len,
+ char *digest)
+{
+ struct inode *inode = dentry->d_inode;
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ char **xattrname;
+ size_t xattr_size = 0;
+ char *xattr_value = NULL;
+ int error;
+ int size;
+
+ if (!inode->i_op || !inode->i_op->getxattr)
+ return -EOPNOTSUPP;
+ error = init_desc(&desc);
+ if (error)
+ return error;
+
+ error = -ENODATA;
+ for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++) {
+ if ((req_xattr_name && req_xattr_value)
+ && !strcmp(*xattrname, req_xattr_name)) {
+ error = 0;
+ sg_init_one(sg, req_xattr_value, req_xattr_value_len);
+ crypto_hash_update(&desc, sg, req_xattr_value_len);
+ continue;
+ }
+ size = vfs_getxattr_alloc(dentry, *xattrname,
+ &xattr_value, xattr_size, GFP_NOFS);
+ if (size == -ENOMEM) {
+ error = -ENOMEM;
+ goto out;
+ }
+ if (size < 0)
+ continue;
+
+ error = 0;
+ xattr_size = size;
+ sg_init_one(sg, xattr_value, xattr_size);
+ crypto_hash_update(&desc, sg, xattr_size);
+ }
+ hmac_add_misc(&desc, inode, digest);
+ kfree(xattr_value);
+out:
+ crypto_free_hash(desc.tfm);
+ return error;
+}
+
+/*
+ * Calculate the hmac and update security.evm xattr
+ */
+int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
+ const char *xattr_value, size_t xattr_value_len,
+ struct integrity_iint_cache *iint)
+{
+ struct inode *inode = dentry->d_inode;
+ int rc = 0;
+
+ memset(iint->hmac, 0, sizeof iint->hmac);
+ rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
+ xattr_value_len, iint->hmac);
+ if (rc == 0)
+ rc = inode->i_op->setxattr(dentry, XATTR_NAME_EVM,
+ iint->hmac, evm_hmac_size, 0);
+ else if (rc == -ENODATA)
+ rc = inode->i_op->removexattr(dentry, XATTR_NAME_EVM);
+ return rc;
+}
+
+/*
+ * Get the key from the TPM for the SHA1-HMAC
+ */
+int evm_init_tpmkernkey(void)
+{
+ struct key *kmk;
+ struct user_key_payload *ukp;
+ int len;
+
+ kmk = request_key(&key_type_user, TPMKEY, NULL);
+ if (IS_ERR(kmk))
+ return -ENOENT;
+
+ down_read(&kmk->sem);
+ ukp = kmk->payload.data;
+ len = ukp->datalen;
+ if (len > MAX_TPMKEY)
+ len = MAX_TPMKEY;
+ tpm_keylen = len;
+ memcpy(tpm_key, ukp->data, len);
+
+ /* burn the original key contents */
+ memset(ukp->data, 0, len);
+ up_read(&kmk->sem);
+ key_put(kmk);
+ return 0;
+}
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
new file mode 100644
index 0000000..59dc148
--- /dev/null
+++ b/security/integrity/evm/evm_main.c
@@ -0,0 +1,296 @@
+/*
+ * Copyright (C) 2005-2010 IBM Corporation
+ *
+ * Author:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * 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: evm_main.c
+ * implements evm_inode_setxattr, evm_inode_post_setxattr,
+ * evm_inode_removexattr, and evm_verifyxattr
+ */
+
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/xattr.h>
+#include <linux/integrity.h>
+#include "evm.h"
+
+int evm_initialized;
+
+char *evm_hmac = "hmac(sha1)";
+int evm_hmac_size = SHA1_DIGEST_SIZE;
+
+char *evm_config_xattrnames[] = {
+#ifdef CONFIG_SECURITY_SELINUX
+ XATTR_NAME_SELINUX,
+#endif
+#ifdef CONFIG_SECURITY_SMACK
+ XATTR_NAME_SMACK,
+#endif
+ XATTR_NAME_CAPS,
+ NULL
+};
+
+/*
+ * evm_verify_hmac - calculate and compare the HMAC with the EVM xattr
+ *
+ * Compute the HMAC on the dentry's protected set of extended attributes
+ * and compare it against the stored security.evm xattr. (For performance,
+ * use the previoulsy retrieved xattr value and length to calculate the
+ * HMAC.)
+ *
+ * Returns integrity status
+ */
+static enum integrity_status evm_verify_hmac(struct dentry *dentry,
+ const char *xattr_name,
+ char *xattr_value,
+ size_t xattr_value_len,
+ struct integrity_iint_cache *iint)
+{
+ char hmac_val[MAX_DIGEST_SIZE];
+ int rc;
+
+ if (iint->hmac_status != INTEGRITY_UNKNOWN)
+ return iint->hmac_status;
+
+ memset(hmac_val, 0, sizeof hmac_val);
+ rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
+ xattr_value_len, hmac_val);
+ if (rc < 0)
+ return INTEGRITY_UNKNOWN;
+
+ rc = vfs_xattr_cmp(dentry, XATTR_NAME_EVM, hmac_val, sizeof hmac_val,
+ GFP_NOFS);
+ if (rc < 0)
+ goto err_out;
+ iint->hmac_status = INTEGRITY_PASS;
+ return iint->hmac_status;
+
+err_out:
+ switch (rc) {
+ case -ENODATA: /* file not labelled */
+ iint->hmac_status = INTEGRITY_NOLABEL;
+ break;
+ case -EINVAL:
+ iint->hmac_status = INTEGRITY_FAIL;
+ break;
+ default:
+ iint->hmac_status = INTEGRITY_UNKNOWN;
+ }
+ return iint->hmac_status;
+}
+
+static int evm_protected_xattr(const char *req_xattr_name)
+{
+ char **xattrname;
+ int found = 0;
+
+ for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++) {
+ if (strncmp(req_xattr_name, *xattrname,
+ strlen(req_xattr_name)) == 0) {
+ found = 1;
+ break;
+ }
+ }
+ return found;
+}
+
+/**
+ * evm_verifyxattr - verify the integrity of the requested xattr
+ * @dentry: object of the verify xattr
+ * @xattr_name: requested xattr
+ * @xattr_value: requested xattr value
+ * @xattr_value_len: requested xattr value length
+ *
+ * Calculate the HMAC for the given dentry and verify it
+ * against the stored security.evm xattr. For performance,
+ * use the xattr value and length previously retrieved
+ * to calculate the HMAC.
+ *
+ * Returns the xattr integrity status.
+ */
+enum integrity_status evm_verifyxattr(struct dentry *dentry,
+ const char *xattr_name,
+ void *xattr_value, size_t xattr_value_len)
+{
+ struct inode *inode = dentry->d_inode;
+ struct integrity_iint_cache *iint;
+ enum integrity_status status;
+
+ if (!evm_initialized || !evm_protected_xattr(xattr_name))
+ return INTEGRITY_UNKNOWN;
+
+ iint = integrity_iint_find_get(inode);
+ if (!iint)
+ return -ENOMEM;
+ mutex_lock(&iint->evm_mutex);
+ status = evm_verify_hmac(dentry, xattr_name, xattr_value,
+ xattr_value_len, iint);
+ mutex_unlock(&iint->evm_mutex);
+ kref_put(&iint->refcount, iint_free);
+ return status;
+}
+EXPORT_SYMBOL_GPL(evm_verifyxattr);
+
+/*
+ * evm_protect_xattr - protect the EVM extended attribute
+ *
+ * Prevent security.evm from being modified or removed.
+ */
+static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ if ((!capable(CAP_MAC_ADMIN))
+ && (strcmp(xattr_name, XATTR_NAME_EVM) == 0))
+ return -EPERM;
+ return 0;
+}
+
+/**
+ * evm_inode_setxattr - protect the EVM extended attribute
+ * @dentry: pointer to the affected dentry
+ * @xattr_name: pointer to the affected extended attribute name
+ * @xattr_value: pointer to the new extended attribute value
+ * @xattr_value_len: pointer to the new extended attribute value length
+ *
+ * Prevent 'security.evm' from being modified
+ */
+int evm_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ return evm_protect_xattr(dentry, xattr_name, xattr_value,
+ xattr_value_len);
+}
+
+/**
+ * evm_inode_removexattr - protect the EVM extended attribute
+ * @dentry: pointer to the affected dentry
+ * @xattr_name: pointer to the affected extended attribute name
+ *
+ * Prevent 'security.evm' from being removed.
+ */
+int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+ return evm_protect_xattr(dentry, xattr_name, NULL, 0);
+}
+
+/*
+ * After updating/removing an extended attribute defined in /etc/evm.config,
+ * update the HMAC(security.evm) to reflect the change.
+ */
+static void evm_postxattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ struct inode *inode = dentry->d_inode;
+ struct integrity_iint_cache *iint;
+ int rc;
+
+ iint = integrity_iint_find_get(inode);
+ if (!iint)
+ return;
+ mutex_lock(&iint->evm_mutex);
+ iint->hmac_status = INTEGRITY_UNKNOWN;
+ rc = evm_update_evmxattr(dentry, xattr_name, xattr_value,
+ xattr_value_len, iint);
+ if (!rc)
+ iint->hmac_status = INTEGRITY_PASS;
+ mutex_unlock(&iint->evm_mutex);
+ kref_put(&iint->refcount, iint_free);
+}
+
+/**
+ * evm_inode_post_setxattr - update 'security.evm' to reflect the changes
+ * @dentry: pointer to the affected dentry
+ * @xattr_name: pointer to the affected extended attribute name
+ * @xattr_value: pointer to the new extended attribute value
+ * @xattr_value_len: pointer to the new extended attribute value length
+ *
+ * Update the HMAC stored in 'security.evm' to reflect the change.
+ */
+void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ if (!evm_initialized || !evm_protected_xattr(xattr_name))
+ return;
+
+ evm_postxattr(dentry, xattr_name, xattr_value, xattr_value_len);
+ return;
+}
+
+/**
+ * evm_inode_post_removexattr - update 'security.evm' after removing the xattr
+ * @dentry: pointer to the affected dentry
+ * @xattr_name: pointer to the affected extended attribute name
+ *
+ * Update the HMAC stored in 'security.evm' to reflect removal of the xattr.
+ */
+void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+ if (!evm_initialized || !evm_protected_xattr(xattr_name))
+ return;
+
+ evm_postxattr(dentry, xattr_name, NULL, 0);
+ return;
+}
+
+/**
+ * evm_inode_post_setattr - update 'security.evm' after modifying metadata
+ * @dentry: pointer to the affected dentry
+ * @ia_valid: for the UID and GID status
+ *
+ * For now, update the HMAC stored in 'security.evm' to reflect UID/GID
+ * changes.
+ */
+void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)
+{
+ if (!evm_initialized)
+ return;
+
+ if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))
+ evm_postxattr(dentry, NULL, NULL, 0);
+ return;
+}
+
+static struct crypto_hash *tfm_hmac; /* preload crypto alg */
+static int __init init_evm(void)
+{
+ int error;
+
+ tfm_hmac = crypto_alloc_hash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
+ error = evm_init_secfs();
+ if (error < 0) {
+ printk(KERN_INFO "EVM: Error registering secfs\n");
+ goto err;
+ }
+err:
+ return error;
+}
+
+static void __exit cleanup_evm(void)
+{
+ evm_cleanup_secfs();
+ crypto_free_hash(tfm_hmac);
+}
+
+/*
+ * evm_display_config - list the EVM protected security extended attributes
+ */
+static int __init evm_display_config(void)
+{
+ char **xattrname;
+
+ for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++)
+ printk(KERN_INFO "EVM: %s\n", *xattrname);
+ return 0;
+}
+
+pure_initcall(evm_display_config);
+late_initcall(init_evm);
+
+MODULE_DESCRIPTION("Extended Verification Module");
+MODULE_LICENSE("GPL");
diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c
new file mode 100644
index 0000000..edb83ac
--- /dev/null
+++ b/security/integrity/evm/evm_secfs.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2010 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * 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: evm_secfs.c
+ * - Used to signal when key is on keyring
+ * - Get the key and enable EVM
+ */
+
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include "evm.h"
+
+static struct dentry *evm_init_tpm;
+
+/**
+ * evm_read_key - read() for <securityfs>/evm
+ *
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @count: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t evm_read_key(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char temp[80];
+ ssize_t rc;
+
+ if (*ppos != 0)
+ return 0;
+
+ sprintf(temp, "%d", evm_initialized);
+ rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
+
+ return rc;
+}
+
+/**
+ * evm_write_key - write() for <securityfs>/evm
+ * @file: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Used to signal that key is on the kernel key ring.
+ * - get the integrity hmac key from the kernel key ring
+ * - create list of hmac protected extended attributes
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t evm_write_key(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char temp[80];
+ int i, error;
+
+ if (!capable(CAP_MAC_ADMIN) || evm_initialized)
+ return -EPERM;
+
+ if (count >= sizeof(temp) || count == 0)
+ return -EINVAL;
+
+ if (copy_from_user(temp, buf, count) != 0)
+ return -EFAULT;
+
+ temp[count] = '\0';
+
+ if ((sscanf(temp, "%d", &i) != 1) || (i != 1))
+ return -EINVAL;
+
+ error = evm_init_tpmkernkey();
+ printk(KERN_INFO "EVM: %s (%d)\n", (error < 0) ?
+ "tpmkernkey initialization failed" : "tpmkernkey initialized",
+ i);
+ if (!error)
+ evm_initialized = 1;
+ return count;
+}
+
+static const struct file_operations evm_key_ops = {
+ .read = evm_read_key,
+ .write = evm_write_key,
+};
+
+int __init evm_init_secfs(void)
+{
+ int error = 0;
+
+ evm_init_tpm = securityfs_create_file("evm", S_IRUSR | S_IRGRP,
+ NULL, NULL, &evm_key_ops);
+ if (!evm_init_tpm || IS_ERR(evm_init_tpm))
+ error = -EFAULT;
+ return error;
+}
+
+void __exit evm_cleanup_secfs(void)
+{
+ if (evm_init_tpm)
+ securityfs_remove(evm_init_tpm);
+}
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index e72c966..1f96f5a 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -133,9 +133,11 @@ static void init_once(void *foo)
iint->version = 0;
iint->flags = 0UL;
mutex_init(&iint->mutex);
+ mutex_init(&iint->evm_mutex);
iint->readcount = 0;
iint->writecount = 0;
iint->opencount = 0;
+ iint->hmac_status = INTEGRITY_UNKNOWN;
kref_init(&iint->refcount);
}
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index f1013c9..c83e475 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -31,6 +31,9 @@ struct integrity_iint_cache {
long opencount; /* opens reference count */
struct kref refcount; /* ima_iint_cache reference count */
struct rcu_head rcu;
+ struct mutex evm_mutex; /* protects: hmac_status, hmac */
+ enum integrity_status hmac_status;
+ u8 hmac[MAX_DIGEST_SIZE];
};
/* radix tree calls to lookup, insert, delete
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 04/14] ima: move ima_file_free before releasing the file
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (2 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 03/14] evm: re-release Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 05/14] security: imbed evm calls in security hooks Mimi Zohar
` (9 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Integrity appraisal measures files on file_free and stores the file
measurement as an xattr. Measure the file before releasing it.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
fs/file_table.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/file_table.c b/fs/file_table.c
index 5c7d10e..6bcb299 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -241,10 +241,10 @@ static void __fput(struct file *file)
if (file->f_op && file->f_op->fasync)
file->f_op->fasync(-1, file, 0);
}
+ ima_file_free(file);
if (file->f_op && file->f_op->release)
file->f_op->release(inode, file);
security_file_free(file);
- ima_file_free(file);
if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL))
cdev_put(inode->i_cdev);
fops_put(file->f_op);
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 05/14] security: imbed evm calls in security hooks
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (3 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 04/14] ima: move ima_file_free before releasing the file Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 06/14] evm: inode post removexattr Mimi Zohar
` (8 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Imbed the evm calls evm_inode_setxattr(), evm_inode_post_setxattr(),
evm_inode_removexattr() in the security hooks. evm_inode_setxattr()
protects security.evm xattr. evm_inode_post_setxattr() and
evm_inode_removexattr() updates the hmac associated with an inode.
(Assumes an LSM module protects the setting/removing of xattr.)
Changelog:
- Don't define evm_verifyxattr(), unless CONFIG_INTEGRITY is enabled.
- xattr_name is a 'const', value is 'void *'
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
include/linux/evm.h | 56 +++++++++++++++++++++++++++++++++++++
security/integrity/evm/evm_main.c | 1 +
security/security.c | 16 +++++++++-
3 files changed, 71 insertions(+), 2 deletions(-)
create mode 100644 include/linux/evm.h
diff --git a/include/linux/evm.h b/include/linux/evm.h
new file mode 100644
index 0000000..8b4e9e3
--- /dev/null
+++ b/include/linux/evm.h
@@ -0,0 +1,56 @@
+/*
+ * evm.h
+ *
+ * Copyright (c) 2009 IBM Corporation
+ * Author: Mimi Zohar <zohar@us.ibm.com>
+ */
+
+#ifndef _LINUX_EVM_H
+#define _LINUX_EVM_H
+
+#include <linux/integrity.h>
+
+#ifdef CONFIG_EVM
+extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
+ const char *xattr_name,
+ void *xattr_value,
+ size_t xattr_value_len);
+extern int evm_inode_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size);
+extern void evm_inode_post_setxattr(struct dentry *dentry,
+ const char *xattr_name,
+ const void *xattr_value,
+ size_t xattr_value_len);
+extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);
+#else
+#ifdef CONFIG_INTEGRITY
+static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
+ const char *xattr_name,
+ void *xattr_value,
+ size_t xattr_value_len)
+{
+ return INTEGRITY_UNKNOWN;
+}
+#endif
+
+static inline int evm_inode_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size)
+{
+ return 0;
+}
+
+static inline void evm_inode_post_setxattr(struct dentry *dentry,
+ const char *xattr_name,
+ const void *xattr_value,
+ size_t xattr_value_len)
+{
+ return;
+}
+
+static inline int evm_inode_removexattr(struct dentry *dentry,
+ const char *xattr_name)
+{
+ return 0;
+}
+#endif /* CONFIG_EVM_H */
+#endif /* LINUX_EVM_H */
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 59dc148..6d3e5f6 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -18,6 +18,7 @@
#include <linux/crypto.h>
#include <linux/xattr.h>
#include <linux/integrity.h>
+#include <linux/evm.h>
#include "evm.h"
int evm_initialized;
diff --git a/security/security.c b/security/security.c
index 36a0de3..c373c5f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -18,6 +18,7 @@
#include <linux/security.h>
#include <linux/integrity.h>
#include <linux/ima.h>
+#include <linux/evm.h>
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
@@ -548,9 +549,14 @@ int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
int security_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
+ int ret;
+
if (unlikely(IS_PRIVATE(dentry->d_inode)))
return 0;
- return security_ops->inode_setxattr(dentry, name, value, size, flags);
+ ret = security_ops->inode_setxattr(dentry, name, value, size, flags);
+ if (ret)
+ return ret;
+ return evm_inode_setxattr(dentry, name, value, size);
}
void security_inode_post_setxattr(struct dentry *dentry, const char *name,
@@ -559,6 +565,7 @@ void security_inode_post_setxattr(struct dentry *dentry, const char *name,
if (unlikely(IS_PRIVATE(dentry->d_inode)))
return;
security_ops->inode_post_setxattr(dentry, name, value, size, flags);
+ evm_inode_post_setxattr(dentry, name, value, size);
}
int security_inode_getxattr(struct dentry *dentry, const char *name)
@@ -577,9 +584,14 @@ int security_inode_listxattr(struct dentry *dentry)
int security_inode_removexattr(struct dentry *dentry, const char *name)
{
+ int ret;
+
if (unlikely(IS_PRIVATE(dentry->d_inode)))
return 0;
- return security_ops->inode_removexattr(dentry, name);
+ ret = security_ops->inode_removexattr(dentry, name);
+ if (ret)
+ return ret;
+ return evm_inode_removexattr(dentry, name);
}
int security_inode_need_killpriv(struct dentry *dentry)
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 06/14] evm: inode post removexattr
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (4 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 05/14] security: imbed evm calls in security hooks Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 07/14] evm: imbed evm_inode_post_setattr Mimi Zohar
` (7 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
When an EVM protected extended attribute is removed, update 'security.evm'.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
fs/xattr.c | 5 ++++-
include/linux/evm.h | 9 +++++++++
2 files changed, 13 insertions(+), 1 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index e1f6b8b..ad7cdc6 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -14,6 +14,7 @@
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/security.h>
+#include <linux/evm.h>
#include <linux/syscalls.h>
#include <linux/module.h>
#include <linux/fsnotify.h>
@@ -294,8 +295,10 @@ vfs_removexattr(struct dentry *dentry, const char *name)
error = inode->i_op->removexattr(dentry, name);
mutex_unlock(&inode->i_mutex);
- if (!error)
+ if (!error) {
fsnotify_xattr(dentry);
+ evm_inode_post_removexattr(dentry, name);
+ }
return error;
}
EXPORT_SYMBOL_GPL(vfs_removexattr);
diff --git a/include/linux/evm.h b/include/linux/evm.h
index 8b4e9e3..a730782 100644
--- a/include/linux/evm.h
+++ b/include/linux/evm.h
@@ -22,6 +22,8 @@ extern void evm_inode_post_setxattr(struct dentry *dentry,
const void *xattr_value,
size_t xattr_value_len);
extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);
+extern void evm_inode_post_removexattr(struct dentry *dentry,
+ const char *xattr_name);
#else
#ifdef CONFIG_INTEGRITY
static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
@@ -52,5 +54,12 @@ static inline int evm_inode_removexattr(struct dentry *dentry,
{
return 0;
}
+
+static inline void evm_inode_post_removexattr(struct dentry *dentry,
+ const char *xattr_name)
+{
+ return;
+}
+
#endif /* CONFIG_EVM_H */
#endif /* LINUX_EVM_H */
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 07/14] evm: imbed evm_inode_post_setattr
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (5 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 06/14] evm: inode post removexattr Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 08/14] evm: inode_post_init Mimi Zohar
` (6 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Changing the inode's metadata may require the 'security.evm' extended
attribute to be re-calculated and updated.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
fs/attr.c | 5 ++++-
include/linux/evm.h | 6 ++++++
2 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/fs/attr.c b/fs/attr.c
index b4fa3b0..9293710 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -13,6 +13,7 @@
#include <linux/fsnotify.h>
#include <linux/fcntl.h>
#include <linux/security.h>
+#include <linux/evm.h>
/* Taken over from the old code... */
@@ -248,8 +249,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
if (ia_valid & ATTR_SIZE)
up_write(&dentry->d_inode->i_alloc_sem);
- if (!error)
+ if (!error) {
fsnotify_change(dentry, ia_valid);
+ evm_inode_post_setattr(dentry, ia_valid);
+ }
return error;
}
diff --git a/include/linux/evm.h b/include/linux/evm.h
index a730782..33a9247 100644
--- a/include/linux/evm.h
+++ b/include/linux/evm.h
@@ -15,6 +15,7 @@ extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
const char *xattr_name,
void *xattr_value,
size_t xattr_value_len);
+extern void evm_inode_post_setattr(struct dentry *dentry, int ia_valid);
extern int evm_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size);
extern void evm_inode_post_setxattr(struct dentry *dentry,
@@ -35,6 +36,11 @@ static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
}
#endif
+static inline void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)
+{
+ return;
+}
+
static inline int evm_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size)
{
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 08/14] evm: inode_post_init
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (6 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 07/14] evm: imbed evm_inode_post_setattr Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 09/14] fs: add evm_inode_post_init calls Mimi Zohar
` (5 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Initialize 'security.evm' for new files. Reduce number of arguments
by defining 'struct xattr'.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
include/linux/evm.h | 11 ++++++++++
include/linux/xattr.h | 6 +++++
security/integrity/evm/evm.h | 3 ++
security/integrity/evm/evm_crypto.c | 19 ++++++++++++++++++
security/integrity/evm/evm_main.c | 36 +++++++++++++++++++++++++++++++++++
5 files changed, 75 insertions(+), 0 deletions(-)
diff --git a/include/linux/evm.h b/include/linux/evm.h
index 33a9247..c3bc089 100644
--- a/include/linux/evm.h
+++ b/include/linux/evm.h
@@ -9,6 +9,7 @@
#define _LINUX_EVM_H
#include <linux/integrity.h>
+#include <linux/xattr.h>
#ifdef CONFIG_EVM
extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
@@ -25,6 +26,9 @@ extern void evm_inode_post_setxattr(struct dentry *dentry,
extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);
extern void evm_inode_post_removexattr(struct dentry *dentry,
const char *xattr_name);
+extern int evm_inode_post_init_security(struct inode *inode,
+ const struct xattr *new,
+ struct xattr *evm);
#else
#ifdef CONFIG_INTEGRITY
static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
@@ -67,5 +71,12 @@ static inline void evm_inode_post_removexattr(struct dentry *dentry,
return;
}
+static inline int evm_inode_post_init_security(struct inode *inode,
+ const struct xattr *new,
+ struct xattr *evm)
+{
+ return -EOPNOTSUPP;
+}
+
#endif /* CONFIG_EVM_H */
#endif /* LINUX_EVM_H */
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 4c35d84..c959929 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -64,6 +64,12 @@ struct xattr_handler {
size_t size, int flags, int handler_flags);
};
+struct xattr {
+ char *name;
+ void *value;
+ size_t value_len;
+};
+
ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
index 0b6f7b2..d98f7b7 100644
--- a/security/integrity/evm/evm.h
+++ b/security/integrity/evm/evm.h
@@ -12,6 +12,7 @@
* File: evm.h
*
*/
+#include <linux/xattr.h>
#include <linux/security.h>
#include "../integrity.h"
@@ -31,5 +32,7 @@ extern int evm_update_evmxattr(struct dentry *dentry,
extern int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len, char *digest);
+extern int evm_init_hmac(struct inode *inode, const struct xattr *xattr,
+ char *hmac_val);
extern int evm_init_secfs(void);
extern void evm_cleanup_secfs(void);
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 4f1be71..e860603 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -150,6 +150,25 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
return rc;
}
+int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr, char *hmac_val)
+{
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ int error;
+
+ error = init_desc(&desc);
+ if (error != 0) {
+ printk(KERN_INFO "init_desc failed\n");
+ return error;
+ }
+
+ sg_init_one(sg, lsm_xattr->value, lsm_xattr->value_len);
+ crypto_hash_update(&desc, sg, lsm_xattr->value_len);
+ hmac_add_misc(&desc, inode, hmac_val);
+ crypto_free_hash(desc.tfm);
+ return 0;
+}
+
/*
* Get the key from the TPM for the SHA1-HMAC
*/
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 6d3e5f6..a3e330d 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -97,6 +97,12 @@ static int evm_protected_xattr(const char *req_xattr_name)
found = 1;
break;
}
+ if (strncmp(req_xattr_name,
+ *xattrname + XATTR_SECURITY_PREFIX_LEN,
+ strlen(req_xattr_name)) == 0) {
+ found = 1;
+ break;
+ }
}
return found;
}
@@ -257,6 +263,36 @@ void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)
return;
}
+/*
+ * evm_inode_post_init_security - initializes security.evm
+ */
+int evm_inode_post_init_security(struct inode *inode, const struct xattr *lsm_xattr,
+ struct xattr *evm_xattr)
+{
+ u8 *hmac_val;
+ int rc;
+
+ if (!evm_initialized || !evm_protected_xattr(lsm_xattr->name))
+ return -EOPNOTSUPP;
+
+ hmac_val = kzalloc(MAX_DIGEST_SIZE, GFP_NOFS);
+ if (!hmac_val)
+ return -ENOMEM;
+
+ rc = evm_init_hmac(inode, lsm_xattr, hmac_val);
+ if (rc < 0)
+ goto out;
+
+ evm_xattr->value = hmac_val;
+ evm_xattr->value_len = evm_hmac_size;
+ evm_xattr->name = XATTR_EVM_SUFFIX;
+ return 0;
+out:
+ kfree(hmac_val);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(evm_inode_post_init_security);
+
static struct crypto_hash *tfm_hmac; /* preload crypto alg */
static int __init init_evm(void)
{
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 09/14] fs: add evm_inode_post_init calls
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (7 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 08/14] evm: inode_post_init Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 10/14] ima: integrity appraisal extension Mimi Zohar
` (4 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
After creating the initial LSM security extended attribute, call
evm_inode_post_init_security() to create the 'security.evm'
extended attribute.
(Support for other fs still needed.)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
fs/ext2/xattr_security.c | 31 ++++++++++++++++++++++++-------
fs/ext3/xattr_security.c | 30 +++++++++++++++++++++++-------
fs/ext4/xattr_security.c | 30 +++++++++++++++++++++++-------
3 files changed, 70 insertions(+), 21 deletions(-)
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index 3004e15..bb460ed 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -9,6 +9,7 @@
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/security.h>
+#include <linux/evm.h>
#include "xattr.h"
static size_t
@@ -50,21 +51,37 @@ int
ext2_init_security(struct inode *inode, struct inode *dir)
{
int err;
- size_t len;
- void *value;
- char *name;
+ struct xattr lsm_xattr;
+ struct xattr evm_xattr;
- err = security_inode_init_security(inode, dir, &name, &value, &len);
+ err = security_inode_init_security(inode, dir, &lsm_xattr.name,
+ &lsm_xattr.value,
+ &lsm_xattr.value_len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
return err;
}
err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
- name, value, len, 0);
- kfree(name);
- kfree(value);
+ lsm_xattr.name, lsm_xattr.value,
+ lsm_xattr.value_len, 0);
+ if (err < 0)
+ goto out;
+
+ err = evm_inode_post_init_security(inode, &lsm_xattr, &evm_xattr);
+ if (err)
+ goto out;
+ err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
+ evm_xattr.name, evm_xattr.value,
+ evm_xattr.value_len, 0);
+ kfree(evm_xattr.value);
+out:
+ kfree(lsm_xattr.name);
+ kfree(lsm_xattr.value);
+ if (err == -EOPNOTSUPP)
+ return 0;
return err;
+
}
const struct xattr_handler ext2_xattr_security_handler = {
diff --git a/fs/ext3/xattr_security.c b/fs/ext3/xattr_security.c
index 03a99bf..6e44368 100644
--- a/fs/ext3/xattr_security.c
+++ b/fs/ext3/xattr_security.c
@@ -10,6 +10,7 @@
#include <linux/ext3_jbd.h>
#include <linux/ext3_fs.h>
#include <linux/security.h>
+#include <linux/evm.h>
#include "xattr.h"
static size_t
@@ -52,20 +53,35 @@ int
ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir)
{
int err;
- size_t len;
- void *value;
- char *name;
+ struct xattr lsm_xattr;
+ struct xattr evm_xattr;
- err = security_inode_init_security(inode, dir, &name, &value, &len);
+ err = security_inode_init_security(inode, dir, &lsm_xattr.name,
+ &lsm_xattr.value,
+ &lsm_xattr.value_len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
return err;
}
err = ext3_xattr_set_handle(handle, inode, EXT3_XATTR_INDEX_SECURITY,
- name, value, len, 0);
- kfree(name);
- kfree(value);
+ lsm_xattr.name, lsm_xattr.value,
+ lsm_xattr.value_len, 0);
+ if (err < 0)
+ goto out;
+
+ err = evm_inode_post_init_security(inode, &lsm_xattr, &evm_xattr);
+ if (err)
+ goto out;
+ err = ext3_xattr_set_handle(handle, inode, EXT3_XATTR_INDEX_SECURITY,
+ evm_xattr.name, evm_xattr.value,
+ evm_xattr.value_len, 0);
+ kfree(evm_xattr.value);
+out:
+ kfree(lsm_xattr.name);
+ kfree(lsm_xattr.value);
+ if (err == -EOPNOTSUPP)
+ return 0;
return err;
}
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 9b21268..8998fda 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -8,6 +8,7 @@
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/slab.h>
+#include <linux/evm.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"
@@ -52,20 +53,35 @@ int
ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir)
{
int err;
- size_t len;
- void *value;
- char *name;
+ struct xattr lsm_xattr;
+ struct xattr evm_xattr;
- err = security_inode_init_security(inode, dir, &name, &value, &len);
+ err = security_inode_init_security(inode, dir, &lsm_xattr.name,
+ &lsm_xattr.value,
+ &lsm_xattr.value_len);
if (err) {
if (err == -EOPNOTSUPP)
return 0;
return err;
}
err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,
- name, value, len, 0);
- kfree(name);
- kfree(value);
+ lsm_xattr.name, lsm_xattr.value,
+ lsm_xattr.value_len, 0);
+ if (err < 0)
+ goto out;
+
+ err = evm_inode_post_init_security(inode, &lsm_xattr, &evm_xattr);
+ if (err)
+ goto out;
+ err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,
+ evm_xattr.name, evm_xattr.value,
+ evm_xattr.value_len, 0);
+ kfree(evm_xattr.value);
+out:
+ kfree(lsm_xattr.name);
+ kfree(lsm_xattr.value);
+ if (err == -EOPNOTSUPP)
+ return 0;
return err;
}
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 10/14] ima: integrity appraisal extension
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (8 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 09/14] fs: add evm_inode_post_init calls Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 11/14] ima: appraise default rules Mimi Zohar
` (3 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
This patch adds local measurement integrity appraisal to IMA. (Taken
from the original EVM postings.) New is the creation and maintainance
of an extended attribute 'security.ima' containing the file hash
measurement. Protection of the xattr is provided by EVM, if enabled
and configured.
Based on policy, IMA calls evm_verifyxattr() to verify the security.ima
xattr integrity and, assuming success, compares the xattr hash value with
the collected file measurement.
Changelog:
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRASE is not enabled.
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing
status, not before. (Found by Joe Perches)
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
Documentation/kernel-parameters.txt | 4 +
include/linux/xattr.h | 3 +
security/integrity/evm/evm_main.c | 3 +
security/integrity/iint.c | 1 +
security/integrity/ima/Kconfig | 15 ++++
security/integrity/ima/Makefile | 2 +
security/integrity/ima/ima.h | 43 ++++++++++-
security/integrity/ima/ima_api.c | 54 +++++++++----
security/integrity/ima/ima_appraise.c | 139 +++++++++++++++++++++++++++++++++
security/integrity/ima/ima_main.c | 77 +++++++++++++++---
security/integrity/integrity.h | 7 ++-
11 files changed, 317 insertions(+), 31 deletions(-)
create mode 100644 security/integrity/ima/ima_appraise.c
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1808f11..4fcaadc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -973,6 +973,10 @@ 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_appraise= [IMA] appraise integrity measurements
+ Format: { "off" | "enforce" | "log" | "fix" }
+ default: "enforce"
+
ima_audit= [IMA]
Format: { "0" | "1" }
0 -- integrity auditing messages. (Default)
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index c959929..c194f5a 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -37,6 +37,9 @@
#define XATTR_EVM_SUFFIX "evm"
#define XATTR_NAME_EVM XATTR_SECURITY_PREFIX XATTR_EVM_SUFFIX
+#define XATTR_IMA_SUFFIX "ima"
+#define XATTR_NAME_IMA XATTR_SECURITY_PREFIX XATTR_IMA_SUFFIX
+
#define XATTR_SELINUX_SUFFIX "selinux"
#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index a3e330d..17c40a1 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -33,6 +33,9 @@ char *evm_config_xattrnames[] = {
#ifdef CONFIG_SECURITY_SMACK
XATTR_NAME_SMACK,
#endif
+#ifdef CONFIG_IMA
+ XATTR_NAME_IMA,
+#endif
XATTR_NAME_CAPS,
NULL
};
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index 1f96f5a..649c459 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -137,6 +137,7 @@ static void init_once(void *foo)
iint->readcount = 0;
iint->writecount = 0;
iint->opencount = 0;
+ iint->hash_status = INTEGRITY_UNKNOWN;
iint->hmac_status = INTEGRITY_UNKNOWN;
kref_init(&iint->refcount);
}
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 19c053b..6b33971 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -54,3 +54,18 @@ config IMA_LSM_RULES
default y
help
Disabling this option will disregard LSM based policy rules.
+
+config IMA_APPRAISE
+ bool "Appraise integrity measurements"
+ depends on IMA
+ default n
+ help
+ This option enables local measurement integrity appraisal.
+ It requires the system to be labeled with a security extended
+ attribute containing the file hash measurement. To protect
+ the security extended attributes from offline attack, enable
+ and configure EVM.
+
+ For more information on integrity appraisal refer to:
+ <http://linux-ima.sourceforge.net>
+ If unsure, say N.
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 5690c02..bd31516 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -7,3 +7,5 @@ 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_audit.o
+
+ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index a58ac9f..854353d 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -37,9 +37,11 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
/* set during initialization */
+extern char *ima_xattr_name;
extern int ima_initialized;
extern int ima_used_chip;
extern char *ima_hash;
+extern int ima_appraise;
/* IMA inode template definition */
struct ima_template_data {
@@ -97,8 +99,9 @@ static inline unsigned long ima_hash_key(u8 *digest)
}
/* LIM API function definitions */
-int ima_must_measure(struct integrity_iint_cache *iint, struct inode *inode,
- int mask, int function);
+int ima_must_appraise_or_measure(struct integrity_iint_cache *iint,
+ struct inode *inode, int mask, int function,
+ int *must_measure, int *must_appraise);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file);
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
@@ -116,7 +119,7 @@ void iint_free(struct kref *kref);
void iint_rcu_free(struct rcu_head *rcu);
/* IMA policy related functions */
-enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK };
+enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK, POST_SETATTR };
int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
void ima_init_policy(void);
@@ -124,6 +127,40 @@ void ima_update_policy(void);
ssize_t ima_parse_add_rule(char *);
void ima_delete_rules(void);
+/* Appraise integrity measurements */
+#define IMA_APPRAISE_ENABLED 0x01
+#define IMA_APPRAISE_ENFORCE 0x02
+#define IMA_APPRAISE_LOG 0x04
+#define IMA_APPRAISE_FIX 0x08
+
+#ifdef CONFIG_IMA_APPRAISE
+int ima_appraise_measurement(struct integrity_iint_cache *iint,
+ struct file *file, const unsigned char *filename);
+int ima_must_appraise(struct integrity_iint_cache *iint, struct inode *inode,
+ enum ima_hooks func, int mask);
+void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
+
+#else
+static inline int ima_appraise_measurement(struct integrity_iint_cache *iint,
+ struct file *file,
+ const unsigned char *filename)
+{
+ return INTEGRITY_UNKNOWN;
+}
+
+static inline int ima_must_appraise(struct integrity_iint_cache *iint,
+ struct inode *inode,
+ enum ima_hooks func, int mask)
+{
+ return 0;
+}
+
+static inline void ima_update_xattr(struct integrity_iint_cache *iint,
+ struct file *file)
+{
+}
+#endif
+
/* 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 42adfd4..37b4ecd 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -9,13 +9,18 @@
* License.
*
* File: ima_api.c
- * Implements must_measure, collect_measurement, store_measurement,
- * and store_template.
+ * Implements must_appraise_or_measure, collect_measurement,
+ * appraise_measurement, store_measurement and store_template.
*/
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/xattr.h>
+#include <linux/evm.h>
#include "ima.h"
+
static const char *IMA_TEMPLATE_NAME = "ima";
/*
@@ -93,10 +98,12 @@ err_out:
}
/**
- * ima_must_measure - measure decision based on policy.
+ * ima_must_appraise_or_measure - appraise & measure decision based on policy.
* @inode: pointer to inode to measure
* @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE)
* @function: calling function (FILE_CHECK, BPRM_CHECK, FILE_MMAP)
+ * @must_measure: pointer to measure flag
+ * @must_appraise: pointer to appraise flag
*
* The policy is defined in terms of keypairs:
* subj=, obj=, type=, func=, mask=, fsmagic=
@@ -107,20 +114,32 @@ err_out:
*
* Must be called with iint->mutex held.
*
- * Return 0 to measure. Return 1 if already measured.
+ * Set must_appraise to 1 to appraise measurement.
+ * Set must_measure to 1 to add to measurement list.
+ *
* For matching a DONT_MEASURE policy, no policy, or other
- * error, return an error code.
+ * error, return an error code, otherwise 0.
*/
-int ima_must_measure(struct integrity_iint_cache *iint, struct inode *inode,
- int mask, int function)
+int ima_must_appraise_or_measure(struct integrity_iint_cache *iint,
+ struct inode *inode, int mask, int function,
+ int *must_measure, int *must_appraise)
{
- int must_measure;
+ int rc;
- if (iint->flags & IMA_MEASURED)
- return 1;
+ if (must_appraise)
+ *must_appraise = ima_must_appraise(iint, inode, function, mask);
- must_measure = ima_match_policy(inode, function, mask);
- return must_measure ? 0 : -EACCES;
+ if (iint->flags & IMA_MEASURED) {
+ if (must_measure)
+ *must_measure = 0;
+ return 0;
+ }
+ rc = ima_match_policy(inode, function, mask);
+ if (rc)
+ iint->flags |= IMA_MEASURE;
+ if (must_measure)
+ *must_measure = rc ? 1 : 0;
+ return rc ? 0 : -EACCES;
}
/*
@@ -136,15 +155,17 @@ int ima_must_measure(struct integrity_iint_cache *iint, struct inode *inode,
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file)
{
- int result = -EEXIST;
+ int result = 0;
- if (!(iint->flags & IMA_MEASURED)) {
+ if (!(iint->flags & IMA_COLLECTED)) {
u64 i_version = file->f_dentry->d_inode->i_version;
memset(iint->digest, 0, IMA_DIGEST_SIZE);
result = ima_calc_hash(file, iint->digest);
- if (!result)
+ if (!result) {
iint->version = i_version;
+ iint->flags |= IMA_COLLECTED;
+ }
}
return result;
}
@@ -174,6 +195,9 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
struct ima_template_entry *entry;
int violation = 0;
+ if (iint->flags & IMA_MEASURED)
+ return;
+
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
new file mode 100644
index 0000000..423a5a4
--- /dev/null
+++ b/security/integrity/ima/ima_appraise.c
@@ -0,0 +1,139 @@
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/xattr.h>
+#include <linux/magic.h>
+#include <linux/evm.h>
+
+#include "ima.h"
+
+static int __init default_appraise_setup(char *str)
+{
+ if (strncmp(str, "off", 3) == 0)
+ ima_appraise = 0;
+ else if (strncmp(str, "log", 3) == 0)
+ ima_appraise = IMA_APPRAISE_ENABLED | IMA_APPRAISE_LOG;
+ else if (strncmp(str, "fix", 3) == 0)
+ ima_appraise = IMA_APPRAISE_ENABLED | IMA_APPRAISE_FIX;
+ return 1;
+}
+
+__setup("ima_appraise=", default_appraise_setup);
+
+/*
+ * ima_must_appraise - set appraise flag
+ *
+ * Return 1 to appraise
+ */
+int ima_must_appraise(struct integrity_iint_cache *iint, struct inode *inode,
+ enum ima_hooks func, int mask)
+{
+ return 0;
+}
+
+static void ima_fix_xattr(struct dentry *dentry,
+ struct integrity_iint_cache *iint)
+{
+ __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
+ iint->digest, IMA_DIGEST_SIZE, 0);
+}
+
+/*
+ * ima_appraise_measurement - appraise file measurement
+ *
+ * Call evm_verifyxattr() to verify the integrity of 'security.ima'.
+ * Assuming success, compare the xattr hash with the collected measurement.
+ *
+ * Return 0 on success, error code otherwise
+ */
+int ima_appraise_measurement(struct integrity_iint_cache *iint,
+ struct file *file, const unsigned char *filename)
+{
+ struct dentry *dentry = file->f_dentry;
+ struct inode *inode = dentry->d_inode;
+ u8 xattr_value[IMA_DIGEST_SIZE];
+ enum integrity_status status = INTEGRITY_UNKNOWN;
+ const char *op = "appraise_data";
+ char *cause = "unknown";
+ int rc;
+
+ if (!ima_appraise || !inode->i_op->getxattr)
+ return 0;
+ if (iint->flags & IMA_APPRAISED)
+ return iint->hash_status;
+
+ rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, xattr_value,
+ IMA_DIGEST_SIZE);
+ if (rc < 0)
+ goto err_out;
+ status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc);
+ if ((rc > 0)
+ && ((status == INTEGRITY_PASS) || (status == INTEGRITY_UNKNOWN))) {
+ if (memcmp(xattr_value, iint->digest, IMA_DIGEST_SIZE) != 0) {
+ status = INTEGRITY_FAIL;
+ cause = "invalid-hash";
+ print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE,
+ xattr_value, IMA_DIGEST_SIZE);
+ print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE,
+ iint->digest, IMA_DIGEST_SIZE);
+ if (ima_appraise & IMA_APPRAISE_FIX)
+ ima_fix_xattr(dentry, iint);
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
+ filename, op, cause, 1, 0);
+ } else {
+ if ((status == INTEGRITY_UNKNOWN)
+ && (ima_appraise & IMA_APPRAISE_FIX))
+ ima_fix_xattr(dentry, iint);
+ status = INTEGRITY_PASS;
+ }
+ iint->flags |= IMA_APPRAISED;
+ } else {
+ if (status == INTEGRITY_NOLABEL)
+ cause = "missing-HMAC";
+ else if (status == INTEGRITY_FAIL)
+ cause = "invalid-HMAC";
+
+ if (ima_appraise & IMA_APPRAISE_FIX)
+ ima_fix_xattr(dentry, iint);
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+ op, cause, 1, 0);
+ }
+ iint->hash_status = status;
+ return status;
+err_out:
+ if (rc == -ENODATA) {
+ if (iint->version == 1)
+ return 0;
+ cause = "missing-hash";
+ if (ima_appraise & IMA_APPRAISE_FIX)
+ ima_fix_xattr(dentry, iint);
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+ op, cause, 1, 0);
+ iint->hash_status = INTEGRITY_NOLABEL;
+ return iint->hash_status;
+ }
+ printk(KERN_INFO "%s: %d %s\n", __func__, rc, filename);
+ return 0;
+}
+
+/*
+ * ima_update_xattr - update 'security.ima' hash value
+ */
+void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
+{
+ struct dentry *dentry = file->f_dentry;
+ int read = 0;
+ int rc = 0;
+
+ if (!(file->f_mode & FMODE_READ)) {
+ file->f_mode |= FMODE_READ;
+ read = 1;
+ }
+ rc = ima_collect_measurement(iint, file);
+ if (read)
+ file->f_mode &= ~FMODE_READ;
+ if (rc < 0)
+ return;
+ __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
+ iint->digest, IMA_DIGEST_SIZE, 0);
+}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 8c231f3..d6132b9 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -23,11 +23,19 @@
#include <linux/mount.h>
#include <linux/mman.h>
#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/ima.h>
#include "ima.h"
int ima_initialized;
+#ifdef CONFIG_IMA_APPRAISE
+int ima_appraise = IMA_APPRAISE_ENABLED | IMA_APPRAISE_ENFORCE;
+#else
+int ima_appraise;
+#endif
+
char *ima_hash = "sha1";
static int __init hash_setup(char *str)
{
@@ -155,7 +163,8 @@ void ima_counts_get(struct file *file)
if (!iint)
return;
mutex_lock(&iint->mutex);
- rc = ima_must_measure(iint, inode, MAY_READ, FILE_CHECK);
+ rc = ima_must_appraise_or_measure(iint, inode, MAY_READ, FILE_CHECK,
+ NULL, NULL);
if (rc < 0)
goto out;
@@ -186,8 +195,12 @@ static void ima_dec_counts(struct integrity_iint_cache *iint,
if (mode & FMODE_WRITE) {
iint->writecount--;
if (iint->writecount == 0) {
- if (iint->version != inode->i_version)
- iint->flags &= ~IMA_MEASURED;
+ if (iint->version != inode->i_version) {
+ iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED
+ | IMA_MEASURED);
+ if (iint->flags & IMA_APPRAISE)
+ ima_update_xattr(iint, file);
+ }
}
}
@@ -200,6 +213,7 @@ static void ima_dec_counts(struct integrity_iint_cache *iint,
iint->opencount);
dump_stack();
}
+ return;
}
/**
@@ -231,7 +245,7 @@ static int process_measurement(struct file *file, const unsigned char *filename,
{
struct inode *inode = file->f_dentry->d_inode;
struct integrity_iint_cache *iint;
- int rc;
+ int rc, err = 0, must_measure, must_appraise;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
@@ -240,17 +254,25 @@ static int process_measurement(struct file *file, const unsigned char *filename,
return -ENOMEM;
mutex_lock(&iint->mutex);
- rc = ima_must_measure(iint, inode, mask, function);
- if (rc != 0)
+ rc = ima_must_appraise_or_measure(iint, inode, mask, function,
+ &must_measure, &must_appraise);
+ if (!must_measure && !must_appraise) {
+ if (iint->flags & IMA_APPRAISED)
+ err = iint->hash_status;
goto out;
+ }
rc = ima_collect_measurement(iint, file);
- if (!rc)
+ if (rc != 0)
+ goto out;
+ if (must_measure)
ima_store_measurement(iint, file, filename);
+ if (must_appraise)
+ err = ima_appraise_measurement(iint, file, filename);
out:
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
- return rc;
+ return (!err) ? 0 : -EACCES;
}
/**
@@ -266,14 +288,14 @@ out:
*/
int ima_file_mmap(struct file *file, unsigned long prot)
{
- int rc;
+ int rc = 0;
if (!file)
return 0;
if (prot & PROT_EXEC)
rc = process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, FILE_MMAP);
- return 0;
+ return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
/**
@@ -295,7 +317,7 @@ int ima_bprm_check(struct linux_binprm *bprm)
rc = process_measurement(bprm->file, bprm->filename,
MAY_EXEC, BPRM_CHECK);
- return 0;
+ return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
/**
@@ -315,10 +337,41 @@ int ima_file_check(struct file *file, int mask)
rc = process_measurement(file, file->f_dentry->d_name.name,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
FILE_CHECK);
- return 0;
+ return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
EXPORT_SYMBOL_GPL(ima_file_check);
+/**
+ * ima_inode_post_setattr - reflect file metadata changes
+ * @dentry: pointer to the affected dentry
+ *
+ * Changes to a dentry's metadata might result in needing to appraise
+ */
+void ima_inode_post_setattr(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ struct integrity_iint_cache *iint;
+ int must_appraise, rc;
+
+ if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode)
+ || !inode->i_op->removexattr)
+ return;
+
+ iint = integrity_iint_find_get(inode);
+ if (!iint)
+ return;
+
+ mutex_lock(&iint->mutex);
+ iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED);
+ must_appraise = ima_must_appraise(iint, inode, MAY_ACCESS,
+ POST_SETATTR);
+ if (!must_appraise)
+ rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA);
+ mutex_unlock(&iint->mutex);
+ kref_put(&iint->refcount, iint_free);
+ return;
+}
+
static int __init init_ima(void)
{
int error;
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index c83e475..3a9b3de 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -18,13 +18,18 @@
#define MAX_DIGEST_SIZE SHA1_DIGEST_SIZE
/* iint cache flags */
-#define IMA_MEASURED 1
+#define IMA_MEASURE 1
+#define IMA_MEASURED 2
+#define IMA_APPRAISE 4
+#define IMA_APPRAISED 8
+#define IMA_COLLECTED 16
/* integrity data associated with an inode */
struct integrity_iint_cache {
u64 version; /* track inode changes */
unsigned long flags;
u8 digest[MAX_DIGEST_SIZE];
+ enum integrity_status hash_status;
struct mutex mutex; /* protects: version, flags, digest */
long readcount; /* measured files readcount */
long writecount; /* measured files writecount */
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 11/14] ima: appraise default rules
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (9 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 10/14] ima: integrity appraisal extension Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 12/14] ima: inode post_setattr Mimi Zohar
` (2 subsequent siblings)
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Unlike the IMA measurement policy, the appraise policy can not be
dependent on runtime process information, such as the task uid,
as the 'security.ima' xattr is written on file close and must
be updated each time the file changes, regardless of the current
task uid. The appraise default policy appraises all files owned
by root.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
security/integrity/ima/ima.h | 2 +
security/integrity/ima/ima_appraise.c | 14 +++++++-
security/integrity/ima/ima_policy.c | 61 +++++++++++++++++++++++++++++++-
3 files changed, 74 insertions(+), 3 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 854353d..72e2607 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -122,6 +122,8 @@ void iint_rcu_free(struct rcu_head *rcu);
enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK, POST_SETATTR };
int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
+int ima_match_appraise_policy(struct inode *inode, enum ima_hooks func,
+ int mask);
void ima_init_policy(void);
void ima_update_policy(void);
ssize_t ima_parse_add_rule(char *);
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 423a5a4..fb402fa 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -28,7 +28,19 @@ __setup("ima_appraise=", default_appraise_setup);
int ima_must_appraise(struct integrity_iint_cache *iint, struct inode *inode,
enum ima_hooks func, int mask)
{
- return 0;
+ int must_appraise, rc = 0;
+
+ if (!ima_appraise || !inode->i_op->getxattr)
+ return 0;
+ else if (iint->flags & IMA_APPRAISED)
+ return 0;
+
+ must_appraise = ima_match_appraise_policy(inode, func, mask);
+ if (must_appraise) {
+ iint->flags |= IMA_APPRAISE;
+ rc = 1;
+ }
+ return rc;
}
static void ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index aef8c0a..7fd84af 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -24,8 +24,11 @@
#define IMA_MASK 0x0002
#define IMA_FSMAGIC 0x0004
#define IMA_UID 0x0008
+#define IMA_OWNER 0x0010
-enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
+enum ima_action { UNKNOWN = -1,
+ DONT_MEASURE = 0, MEASURE,
+ DONT_APPRAISE, APPRAISE};
#define MAX_LSM_RULES 6
enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
@@ -40,6 +43,7 @@ struct ima_measure_rule_entry {
int mask;
unsigned long fsmagic;
uid_t uid;
+ uid_t owner;
struct {
void *rule; /* LSM file metadata specific */
int type; /* audit type */
@@ -48,7 +52,7 @@ struct ima_measure_rule_entry {
/*
* Without LSM specific knowledge, the default policy can only be
- * written in terms of .action, .func, .mask, .fsmagic, and .uid
+ * written in terms of .action, .func, .mask, .fsmagic, .uid, and .owner
*/
/*
@@ -70,6 +74,13 @@ static struct ima_measure_rule_entry default_rules[] = {
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE,.func = FILE_CHECK,.mask = MAY_READ,.uid = 0,
.flags = IMA_FUNC | IMA_MASK | IMA_UID},
+ {.action = DONT_APPRAISE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = APPRAISE,.owner = 0,.flags = IMA_OWNER},
};
static LIST_HEAD(measure_default_rules);
@@ -110,6 +121,8 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
return false;
if ((rule->flags & IMA_UID) && rule->uid != tsk->cred->uid)
return false;
+ if ((rule->flags & IMA_OWNER) && rule->owner != inode->i_uid)
+ return false;
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid, sid;
@@ -166,6 +179,9 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
list_for_each_entry(entry, ima_measure, list) {
bool rc;
+ if ((entry->action == APPRAISE) ||
+ (entry->action == DONT_APPRAISE))
+ continue;
rc = ima_match_rules(entry, inode, func, mask);
if (rc)
return entry->action;
@@ -173,6 +189,28 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
return 0;
}
+int ima_match_appraise_policy(struct inode *inode, enum ima_hooks func,
+ int mask)
+{
+ struct ima_measure_rule_entry *entry;
+
+ list_for_each_entry(entry, ima_measure, list) {
+ bool rc;
+
+ if ((entry->action == MEASURE) ||
+ (entry->action == DONT_MEASURE))
+ continue;
+ rc = ima_match_rules(entry, inode, func, mask);
+ if (rc) {
+ if (entry->action == DONT_APPRAISE)
+ return 0;
+ if (entry->action == APPRAISE)
+ return 1;
+ }
+ }
+ return 0;
+}
+
/**
* ima_init_policy - initialize the default measure rules.
*
@@ -220,6 +258,7 @@ void ima_update_policy(void)
enum {
Opt_err = -1,
Opt_measure = 1, Opt_dont_measure,
+ Opt_appraise, Opt_dont_appraise,
Opt_obj_user, Opt_obj_role, Opt_obj_type,
Opt_subj_user, Opt_subj_role, Opt_subj_type,
Opt_func, Opt_mask, Opt_fsmagic, Opt_uid
@@ -228,6 +267,8 @@ enum {
static match_table_t policy_tokens = {
{Opt_measure, "measure"},
{Opt_dont_measure, "dont_measure"},
+ {Opt_appraise, "appraise"},
+ {Opt_dont_appraise, "dont_appraise"},
{Opt_obj_user, "obj_user=%s"},
{Opt_obj_role, "obj_role=%s"},
{Opt_obj_type, "obj_type=%s"},
@@ -300,6 +341,22 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
entry->action = DONT_MEASURE;
break;
+ case Opt_appraise:
+ ima_log_string(ab, "%s ", "appraise");
+
+ if (entry->action != UNKNOWN)
+ result = -EINVAL;
+
+ entry->action = APPRAISE;
+ break;
+ case Opt_dont_appraise:
+ ima_log_string(ab, "%s ", "dont_appraise");
+
+ if (entry->action != UNKNOWN)
+ result = -EINVAL;
+
+ entry->action = DONT_APPRAISE;
+ break;
case Opt_func:
ima_log_string(ab, "func", args[0].from);
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 12/14] ima: inode post_setattr
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (10 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 11/14] ima: appraise default rules Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 13/14] ima: add ima_inode_setxattr and ima_inode_removexattr Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 14/14] ima: appraise measurement required Mimi Zohar
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Changing an inode's metadata may result in our not needing to
appraise the file. In such cases, we must remove 'security.ima'.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
---
fs/attr.c | 2 ++
include/linux/ima.h | 6 ++++++
2 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/fs/attr.c b/fs/attr.c
index 9293710..f410bde 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -14,6 +14,7 @@
#include <linux/fcntl.h>
#include <linux/security.h>
#include <linux/evm.h>
+#include <linux/ima.h>
/* Taken over from the old code... */
@@ -251,6 +252,7 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
if (!error) {
fsnotify_change(dentry, ia_valid);
+ ima_inode_post_setattr(dentry);
evm_inode_post_setattr(dentry, ia_valid);
}
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 4dce900..ce82e29 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -19,6 +19,7 @@ extern int ima_file_check(struct file *file, int mask);
extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
extern void ima_counts_get(struct file *file);
+extern void ima_inode_post_setattr(struct dentry *dentry);
#else
static inline int ima_bprm_check(struct linux_binprm *bprm)
@@ -46,5 +47,10 @@ static inline void ima_counts_get(struct file *file)
return;
}
+static inline void ima_inode_post_setattr(struct dentry *dentry)
+{
+ return;
+}
+
#endif /* CONFIG_IMA_H */
#endif /* _LINUX_IMA_H */
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 13/14] ima: add ima_inode_setxattr and ima_inode_removexattr
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (11 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 12/14] ima: inode post_setattr Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
2010-07-22 20:44 ` [PATCH v2 14/14] ima: appraise measurement required Mimi Zohar
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Based on xattr_permission comments, the restriction to modify
'security' xattr is left up to the underlying fs or lsm. Ensure
that not just anyone can modify or remove 'security.ima'.
Changelog:
- static inline ima_inode_setxattr()/ima_inode_removexattr() stubs
- ima_protect_xattr should be static
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
---
include/linux/ima.h | 16 ++++++++++++++++
security/integrity/ima/ima_main.c | 26 ++++++++++++++++++++++++++
security/security.c | 6 ++++++
3 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/include/linux/ima.h b/include/linux/ima.h
index ce82e29..2f87cf8 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -20,6 +20,9 @@ extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
extern void ima_counts_get(struct file *file);
extern void ima_inode_post_setattr(struct dentry *dentry);
+extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len);
+extern int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name);
#else
static inline int ima_bprm_check(struct linux_binprm *bprm)
@@ -52,5 +55,18 @@ static inline void ima_inode_post_setattr(struct dentry *dentry)
return;
}
+static inline int ima_inode_setxattr(struct dentry *dentry,
+ const char *xattr_name,
+ const void *xattr_value,
+ size_t xattr_value_len)
+{
+ return 0;
+}
+
+static inline int ima_inode_removexattr(struct dentry *dentry,
+ const char *xattr_name)
+{
+ return 0;
+}
#endif /* CONFIG_IMA_H */
#endif /* _LINUX_IMA_H */
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index d6132b9..3713d55 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -372,6 +372,32 @@ void ima_inode_post_setattr(struct dentry *dentry)
return;
}
+/*
+ * ima_protect_xattr - protect 'security.ima'
+ *
+ * Ensure that not just anyone can modify or remove 'security.ima'.
+ */
+static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ if ((strcmp(xattr_name, XATTR_NAME_IMA) == 0)
+ && !capable(CAP_MAC_ADMIN))
+ return -EPERM;
+ return 0;
+}
+
+int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+ const void *xattr_value, size_t xattr_value_len)
+{
+ return ima_protect_xattr(dentry, xattr_name, xattr_value,
+ xattr_value_len);
+}
+
+int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+ return ima_protect_xattr(dentry, xattr_name, NULL, 0);
+}
+
static int __init init_ima(void)
{
int error;
diff --git a/security/security.c b/security/security.c
index c373c5f..53c6285 100644
--- a/security/security.c
+++ b/security/security.c
@@ -556,6 +556,9 @@ int security_inode_setxattr(struct dentry *dentry, const char *name,
ret = security_ops->inode_setxattr(dentry, name, value, size, flags);
if (ret)
return ret;
+ ret = ima_inode_setxattr(dentry, name, value, size);
+ if (ret)
+ return ret;
return evm_inode_setxattr(dentry, name, value, size);
}
@@ -591,6 +594,9 @@ int security_inode_removexattr(struct dentry *dentry, const char *name)
ret = security_ops->inode_removexattr(dentry, name);
if (ret)
return ret;
+ ret = ima_inode_removexattr(dentry, name);
+ if (ret)
+ return ret;
return evm_inode_removexattr(dentry, name);
}
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 14/14] ima: appraise measurement required
2010-07-22 20:44 [PATCH v2 00/14] EVM Mimi Zohar
` (12 preceding siblings ...)
2010-07-22 20:44 ` [PATCH v2 13/14] ima: add ima_inode_setxattr and ima_inode_removexattr Mimi Zohar
@ 2010-07-22 20:44 ` Mimi Zohar
13 siblings, 0 replies; 15+ messages in thread
From: Mimi Zohar @ 2010-07-22 20:44 UTC (permalink / raw)
To: linux-kernel
Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
David Safford, Dave Hansen, Mimi Zohar
Even if allowed to update security.ima, reset the appraisal
flags, forcing re-appraisal.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
---
security/integrity/ima/ima_main.c | 33 +++++++++++++++++++++++++++++++--
1 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 3713d55..0dbfdd6 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -386,18 +386,47 @@ static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name,
return 0;
}
+static void ima_reset_appraise_flags(struct inode *inode)
+{
+ struct integrity_iint_cache *iint;
+
+ if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode))
+ return;
+
+ iint = integrity_iint_find_get(inode);
+ if (!iint)
+ return;
+
+ mutex_lock(&iint->mutex);
+ iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED);
+ mutex_unlock(&iint->mutex);
+ kref_put(&iint->refcount, iint_free);
+ return;
+}
+
int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
const void *xattr_value, size_t xattr_value_len)
{
- return ima_protect_xattr(dentry, xattr_name, xattr_value,
+ int result;
+
+ result = ima_protect_xattr(dentry, xattr_name, xattr_value,
xattr_value_len);
+ if (!result)
+ ima_reset_appraise_flags(dentry->d_inode);
+ return result;
}
int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
{
- return ima_protect_xattr(dentry, xattr_name, NULL, 0);
+ int result;
+
+ result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
+ if (!result)
+ ima_reset_appraise_flags(dentry->d_inode);
+ return result;
}
+
static int __init init_ima(void)
{
int error;
--
1.7.1.1
^ permalink raw reply related [flat|nested] 15+ messages in thread