Initial commit; kernel source import

security/integrity/Kconfig

@@ -0,0 +1,33 @@
+#
+config INTEGRITY
+	def_bool y
+	depends on IMA || EVM
+
+config INTEGRITY_SIGNATURE
+	boolean "Digital signature verification using multiple keyrings"
+	depends on INTEGRITY && KEYS
+	default n
+	select SIGNATURE
+	help
+	  This option enables digital signature verification support
+	  using multiple keyrings. It defines separate keyrings for each
+	  of the different use cases - evm, ima, and modules.
+	  Different keyrings improves search performance, but also allow
+	  to "lock" certain keyring to prevent adding new keys.
+	  This is useful for evm and module keyrings, when keys are
+	  usually only added from initramfs.
+
+config INTEGRITY_ASYMMETRIC_KEYS
+	boolean "Enable asymmetric keys support"
+	depends on INTEGRITY_SIGNATURE
+	default n
+        select ASYMMETRIC_KEY_TYPE
+        select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+        select PUBLIC_KEY_ALGO_RSA
+        select X509_CERTIFICATE_PARSER
+	help
+	  This option enables digital signature verification using
+	  asymmetric keys.
+
+source security/integrity/ima/Kconfig
+source security/integrity/evm/Kconfig

security/integrity/Makefile

@@ -0,0 +1,14 @@
+#
+# Makefile for caching inode integrity data (iint)
+#
+
+obj-$(CONFIG_INTEGRITY) += integrity.o
+obj-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o
+obj-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o
+
+integrity-y := iint.o
+
+subdir-$(CONFIG_IMA)			+= ima
+obj-$(CONFIG_IMA)			+= ima/built-in.o
+subdir-$(CONFIG_EVM)			+= evm
+obj-$(CONFIG_EVM)			+= evm/built-in.o

security/integrity/digsig.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2011 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/rbtree.h>
+#include <linux/key-type.h>
+#include <linux/digsig.h>
+
+#include "integrity.h"
+
+static struct key *keyring[INTEGRITY_KEYRING_MAX];
+
+static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
+	"_evm",
+	"_module",
+	"_ima",
+};
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+					const char *digest, int digestlen)
+{
+	if (id >= INTEGRITY_KEYRING_MAX)
+		return -EINVAL;
+
+	if (!keyring[id]) {
+		keyring[id] =
+			request_key(&key_type_keyring, keyring_name[id], NULL);
+		if (IS_ERR(keyring[id])) {
+			int err = PTR_ERR(keyring[id]);
+			pr_err("no %s keyring: %d\n", keyring_name[id], err);
+			keyring[id] = NULL;
+			return err;
+		}
+	}
+
+	switch (sig[0]) {
+	case 1:
+		return digsig_verify(keyring[id], sig, siglen,
+				     digest, digestlen);
+	case 2:
+		return asymmetric_verify(keyring[id], sig, siglen,
+					 digest, digestlen);
+	}
+
+	return -EOPNOTSUPP;
+}

security/integrity/digsig_asymmetric.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2013 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/key-type.h>
+#include <crypto/public_key.h>
+#include <keys/asymmetric-type.h>
+
+#include "integrity.h"
+
+/*
+ * signature format v2 - for using with asymmetric keys
+ */
+struct signature_v2_hdr {
+	uint8_t version;	/* signature format version */
+	uint8_t	hash_algo;	/* Digest algorithm [enum pkey_hash_algo] */
+	uint32_t keyid;		/* IMA key identifier - not X509/PGP specific*/
+	uint16_t sig_size;	/* signature size */
+	uint8_t sig[0];		/* signature payload */
+} __packed;
+
+/*
+ * Request an asymmetric key.
+ */
+static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
+{
+	struct key *key;
+	char name[12];
+
+	sprintf(name, "id:%x", keyid);
+
+	pr_debug("key search: \"%s\"\n", name);
+
+	if (keyring) {
+		/* search in specific keyring */
+		key_ref_t kref;
+		kref = keyring_search(make_key_ref(keyring, 1),
+				      &key_type_asymmetric, name);
+		if (IS_ERR(kref))
+			key = ERR_CAST(kref);
+		else
+			key = key_ref_to_ptr(kref);
+	} else {
+		key = request_key(&key_type_asymmetric, name, NULL);
+	}
+
+	if (IS_ERR(key)) {
+		pr_warn("Request for unknown key '%s' err %ld\n",
+			name, PTR_ERR(key));
+		switch (PTR_ERR(key)) {
+			/* Hide some search errors */
+		case -EACCES:
+		case -ENOTDIR:
+		case -EAGAIN:
+			return ERR_PTR(-ENOKEY);
+		default:
+			return key;
+		}
+	}
+
+	pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));
+
+	return key;
+}
+
+int asymmetric_verify(struct key *keyring, const char *sig,
+		      int siglen, const char *data, int datalen)
+{
+	struct public_key_signature pks;
+	struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
+	struct key *key;
+	int ret = -ENOMEM;
+
+	if (siglen <= sizeof(*hdr))
+		return -EBADMSG;
+
+	siglen -= sizeof(*hdr);
+
+	if (siglen != __be16_to_cpu(hdr->sig_size))
+		return -EBADMSG;
+
+	if (hdr->hash_algo >= PKEY_HASH__LAST)
+		return -ENOPKG;
+
+	key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
+	if (IS_ERR(key))
+		return PTR_ERR(key);
+
+	memset(&pks, 0, sizeof(pks));
+
+	pks.pkey_hash_algo = hdr->hash_algo;
+	pks.digest = (u8 *)data;
+	pks.digest_size = datalen;
+	pks.nr_mpi = 1;
+	pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
+
+	if (pks.rsa.s)
+		ret = verify_signature(key, &pks);
+
+	mpi_free(pks.rsa.s);
+	key_put(key);
+	pr_debug("%s() = %d\n", __func__, ret);
+	return ret;
+}

security/integrity/evm/Kconfig

@@ -0,0 +1,26 @@
+config EVM
+	boolean "EVM support"
+	depends on SECURITY && KEYS && (TRUSTED_KEYS=y || TRUSTED_KEYS=n)
+	select CRYPTO_HMAC
+	select CRYPTO_MD5
+	select CRYPTO_SHA1
+	select ENCRYPTED_KEYS
+	default n
+	help
+	  EVM protects a file's security extended attributes against
+	  integrity attacks.
+
+	  If you are unsure how to answer this question, answer N.
+
+config EVM_HMAC_VERSION
+	int "EVM HMAC version"
+	depends on EVM
+	default 2
+	help
+	  This options adds EVM HMAC version support.
+	  1 - original version
+	  2 - add per filesystem unique identifier (UUID) (default)
+
+	  WARNING: changing the HMAC calculation method or adding 
+	  additional info to the calculation, requires existing EVM
+	  labeled file systems to be relabeled.  

security/integrity/evm/Makefile

@@ -0,0 +1,7 @@
+#
+# Makefile for building the Extended Verification Module(EVM)
+#
+obj-$(CONFIG_EVM) += evm.o
+
+evm-y := evm_main.o evm_crypto.o evm_secfs.o
+evm-$(CONFIG_FS_POSIX_ACL) += evm_posix_acl.o

security/integrity/evm/evm.h

@@ -0,0 +1,50 @@
+/*
+ * 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
+ *
+ */
+
+#ifndef __INTEGRITY_EVM_H
+#define __INTEGRITY_EVM_H
+
+#include <linux/xattr.h>
+#include <linux/security.h>
+
+#include "../integrity.h"
+
+extern int evm_initialized;
+extern char *evm_hmac;
+extern char *evm_hash;
+extern int evm_hmac_version;
+
+extern struct crypto_shash *hmac_tfm;
+extern struct crypto_shash *hash_tfm;
+
+/* List of EVM protected security xattrs */
+extern char *evm_config_xattrnames[];
+
+extern int evm_init_key(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);
+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_calc_hash(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);
+
+#endif

security/integrity/evm/evm_crypto.c

@@ -0,0 +1,260 @@
+/*
+ * 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/encrypted-type.h>
+#include <crypto/hash.h>
+#include "evm.h"
+
+#define EVMKEY "evm-key"
+#define MAX_KEY_SIZE 128
+static unsigned char evmkey[MAX_KEY_SIZE];
+static int evmkey_len = MAX_KEY_SIZE;
+
+struct crypto_shash *hmac_tfm;
+struct crypto_shash *hash_tfm;
+
+static DEFINE_MUTEX(mutex);
+
+static struct shash_desc *init_desc(char type)
+{
+	long rc;
+	char *algo;
+	struct crypto_shash **tfm;
+	struct shash_desc *desc;
+
+	if (type == EVM_XATTR_HMAC) {
+		tfm = &hmac_tfm;
+		algo = evm_hmac;
+	} else {
+		tfm = &hash_tfm;
+		algo = evm_hash;
+	}
+
+	if (*tfm == NULL) {
+		mutex_lock(&mutex);
+		if (*tfm)
+			goto out;
+		*tfm = crypto_alloc_shash(algo, 0, CRYPTO_ALG_ASYNC);
+		if (IS_ERR(*tfm)) {
+			rc = PTR_ERR(*tfm);
+			pr_err("Can not allocate %s (reason: %ld)\n", algo, rc);
+			*tfm = NULL;
+			mutex_unlock(&mutex);
+			return ERR_PTR(rc);
+		}
+		if (type == EVM_XATTR_HMAC) {
+			rc = crypto_shash_setkey(*tfm, evmkey, evmkey_len);
+			if (rc) {
+				crypto_free_shash(*tfm);
+				*tfm = NULL;
+				mutex_unlock(&mutex);
+				return ERR_PTR(rc);
+			}
+		}
+out:
+		mutex_unlock(&mutex);
+	}
+
+	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
+			GFP_KERNEL);
+	if (!desc)
+		return ERR_PTR(-ENOMEM);
+
+	desc->tfm = *tfm;
+	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	rc = crypto_shash_init(desc);
+	if (rc) {
+		kfree(desc);
+		return ERR_PTR(rc);
+	}
+	return desc;
+}
+
+/* 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 shash_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;
+
+	memset(&hmac_misc, 0, sizeof hmac_misc);
+	hmac_misc.ino = inode->i_ino;
+	hmac_misc.generation = inode->i_generation;
+	hmac_misc.uid = from_kuid(&init_user_ns, inode->i_uid);
+	hmac_misc.gid = from_kgid(&init_user_ns, inode->i_gid);
+	hmac_misc.mode = inode->i_mode;
+	crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof hmac_misc);
+	if (evm_hmac_version > 1)
+		crypto_shash_update(desc, inode->i_sb->s_uuid,
+				    sizeof(inode->i_sb->s_uuid));
+	crypto_shash_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.
+ */
+static int evm_calc_hmac_or_hash(struct dentry *dentry,
+				const char *req_xattr_name,
+				const char *req_xattr_value,
+				size_t req_xattr_value_len,
+				char type, char *digest)
+{
+	struct inode *inode = dentry->d_inode;
+	struct shash_desc *desc;
+	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;
+	desc = init_desc(type);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	error = -ENODATA;
+	for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++) {
+		if ((req_xattr_name && req_xattr_value)
+		    && !strcmp(*xattrname, req_xattr_name)) {
+			error = 0;
+			crypto_shash_update(desc, (const u8 *)req_xattr_value,
+					     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;
+		crypto_shash_update(desc, (const u8 *)xattr_value, xattr_size);
+	}
+	hmac_add_misc(desc, inode, digest);
+
+out:
+	kfree(xattr_value);
+	kfree(desc);
+	return error;
+}
+
+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)
+{
+	return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
+				req_xattr_value_len, EVM_XATTR_HMAC, digest);
+}
+
+int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
+		  const char *req_xattr_value, size_t req_xattr_value_len,
+		  char *digest)
+{
+	return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
+				req_xattr_value_len, IMA_XATTR_DIGEST, digest);
+}
+
+/*
+ * Calculate the hmac and update security.evm xattr
+ *
+ * Expects to be called with i_mutex locked.
+ */
+int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
+			const char *xattr_value, size_t xattr_value_len)
+{
+	struct inode *inode = dentry->d_inode;
+	struct evm_ima_xattr_data xattr_data;
+	int rc = 0;
+
+	rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
+			   xattr_value_len, xattr_data.digest);
+	if (rc == 0) {
+		xattr_data.type = EVM_XATTR_HMAC;
+		rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_EVM,
+					   &xattr_data,
+					   sizeof(xattr_data), 0);
+	} else if (rc == -ENODATA && inode->i_op->removexattr) {
+		rc = inode->i_op->removexattr(dentry, XATTR_NAME_EVM);
+	}
+	return rc;
+}
+
+int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr,
+		  char *hmac_val)
+{
+	struct shash_desc *desc;
+
+	desc = init_desc(EVM_XATTR_HMAC);
+	if (IS_ERR(desc)) {
+		printk(KERN_INFO "init_desc failed\n");
+		return PTR_ERR(desc);
+	}
+
+	crypto_shash_update(desc, lsm_xattr->value, lsm_xattr->value_len);
+	hmac_add_misc(desc, inode, hmac_val);
+	kfree(desc);
+	return 0;
+}
+
+/*
+ * Get the key from the TPM for the SHA1-HMAC
+ */
+int evm_init_key(void)
+{
+	struct key *evm_key;
+	struct encrypted_key_payload *ekp;
+	int rc = 0;
+
+	evm_key = request_key(&key_type_encrypted, EVMKEY, NULL);
+	if (IS_ERR(evm_key))
+		return -ENOENT;
+
+	down_read(&evm_key->sem);
+	ekp = evm_key->payload.data;
+	if (ekp->decrypted_datalen > MAX_KEY_SIZE) {
+		rc = -EINVAL;
+		goto out;
+	}
+	memcpy(evmkey, ekp->decrypted_data, ekp->decrypted_datalen);
+out:
+	/* burn the original key contents */
+	memset(ekp->decrypted_data, 0, ekp->decrypted_datalen);
+	up_read(&evm_key->sem);
+	key_put(evm_key);
+	return rc;
+}

security/integrity/evm/evm_main.c

@@ -0,0 +1,447 @@
+/*
+ * 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 <linux/evm.h>
+#include <crypto/hash.h>
+#include "evm.h"
+
+int evm_initialized;
+
+char *evm_hmac = "hmac(sha1)";
+char *evm_hash = "sha1";
+int evm_hmac_version = CONFIG_EVM_HMAC_VERSION;
+
+char *evm_config_xattrnames[] = {
+#ifdef CONFIG_SECURITY_SELINUX
+	XATTR_NAME_SELINUX,
+#endif
+#ifdef CONFIG_SECURITY_SMACK
+	XATTR_NAME_SMACK,
+#endif
+#ifdef CONFIG_IMA_APPRAISE
+	XATTR_NAME_IMA,
+#endif
+	XATTR_NAME_CAPS,
+	NULL
+};
+
+static int evm_fixmode;
+static int __init evm_set_fixmode(char *str)
+{
+	if (strncmp(str, "fix", 3) == 0)
+		evm_fixmode = 1;
+	return 0;
+}
+__setup("evm=", evm_set_fixmode);
+
+static int evm_find_protected_xattrs(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	char **xattr;
+	int error;
+	int count = 0;
+
+	if (!inode->i_op || !inode->i_op->getxattr)
+		return -EOPNOTSUPP;
+
+	for (xattr = evm_config_xattrnames; *xattr != NULL; xattr++) {
+		error = inode->i_op->getxattr(dentry, *xattr, NULL, 0);
+		if (error < 0) {
+			if (error == -ENODATA)
+				continue;
+			return error;
+		}
+		count++;
+	}
+
+	return count;
+}
+
+/*
+ * 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.)
+ * - cache the verification result in the iint, when available.
+ *
+ * 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)
+{
+	struct evm_ima_xattr_data *xattr_data = NULL;
+	struct evm_ima_xattr_data calc;
+	enum integrity_status evm_status = INTEGRITY_PASS;
+	int rc, xattr_len;
+
+	if (iint && iint->evm_status == INTEGRITY_PASS)
+		return iint->evm_status;
+
+	/* if status is not PASS, try to check again - against -ENOMEM */
+
+	/* first need to know the sig type */
+	rc = vfs_getxattr_alloc(dentry, XATTR_NAME_EVM, (char **)&xattr_data, 0,
+				GFP_NOFS);
+	if (rc <= 0) {
+		if (rc == 0)
+			evm_status = INTEGRITY_FAIL; /* empty */
+		else if (rc == -ENODATA) {
+			rc = evm_find_protected_xattrs(dentry);
+			if (rc > 0)
+				evm_status = INTEGRITY_NOLABEL;
+			else if (rc == 0)
+				evm_status = INTEGRITY_NOXATTRS; /* new file */
+		}
+		goto out;
+	}
+
+	xattr_len = rc - 1;
+
+	/* check value type */
+	switch (xattr_data->type) {
+	case EVM_XATTR_HMAC:
+		rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
+				   xattr_value_len, calc.digest);
+		if (rc)
+			break;
+		rc = memcmp(xattr_data->digest, calc.digest,
+			    sizeof(calc.digest));
+		if (rc)
+			rc = -EINVAL;
+		break;
+	case EVM_IMA_XATTR_DIGSIG:
+		rc = evm_calc_hash(dentry, xattr_name, xattr_value,
+				xattr_value_len, calc.digest);
+		if (rc)
+			break;
+		rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
+					xattr_data->digest, xattr_len,
+					calc.digest, sizeof(calc.digest));
+		if (!rc) {
+			/* we probably want to replace rsa with hmac here */
+			evm_update_evmxattr(dentry, xattr_name, xattr_value,
+				   xattr_value_len);
+		}
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	if (rc)
+		evm_status = (rc == -ENODATA) ?
+				INTEGRITY_NOXATTRS : INTEGRITY_FAIL;
+out:
+	if (iint)
+		iint->evm_status = evm_status;
+	kfree(xattr_data);
+	return evm_status;
+}
+
+static int evm_protected_xattr(const char *req_xattr_name)
+{
+	char **xattrname;
+	int namelen;
+	int found = 0;
+
+	namelen = strlen(req_xattr_name);
+	for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++) {
+		if ((strlen(*xattrname) == namelen)
+		    && (strncmp(req_xattr_name, *xattrname, namelen) == 0)) {
+			found = 1;
+			break;
+		}
+		if (strncmp(req_xattr_name,
+			    *xattrname + XATTR_SECURITY_PREFIX_LEN,
+			    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.
+ *
+ * This function requires the caller to lock the inode's i_mutex before it
+ * is executed.
+ */
+enum integrity_status evm_verifyxattr(struct dentry *dentry,
+				      const char *xattr_name,
+				      void *xattr_value, size_t xattr_value_len,
+				      struct integrity_iint_cache *iint)
+{
+	if (!evm_initialized || !evm_protected_xattr(xattr_name))
+		return INTEGRITY_UNKNOWN;
+
+	if (!iint) {
+		iint = integrity_iint_find(dentry->d_inode);
+		if (!iint)
+			return INTEGRITY_UNKNOWN;
+	}
+	return evm_verify_hmac(dentry, xattr_name, xattr_value,
+				 xattr_value_len, iint);
+}
+EXPORT_SYMBOL_GPL(evm_verifyxattr);
+
+/*
+ * evm_verify_current_integrity - verify the dentry's metadata integrity
+ * @dentry: pointer to the affected dentry
+ *
+ * Verify and return the dentry's metadata integrity. The exceptions are
+ * before EVM is initialized or in 'fix' mode.
+ */
+static enum integrity_status evm_verify_current_integrity(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+
+	if (!evm_initialized || !S_ISREG(inode->i_mode) || evm_fixmode)
+		return 0;
+	return evm_verify_hmac(dentry, NULL, NULL, 0, NULL);
+}
+
+/*
+ * evm_protect_xattr - protect the EVM extended attribute
+ *
+ * Prevent security.evm from being modified or removed without the
+ * necessary permissions or when the existing value is invalid.
+ *
+ * The posix xattr acls are 'system' prefixed, which normally would not
+ * affect security.evm.  An interesting side affect of writing posix xattr
+ * acls is their modifying of the i_mode, which is included in security.evm.
+ * For posix xattr acls only, permit security.evm, even if it currently
+ * doesn't exist, to be updated.
+ */
+static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name,
+			     const void *xattr_value, size_t xattr_value_len)
+{
+	enum integrity_status evm_status;
+
+	if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) {
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+	} else if (!evm_protected_xattr(xattr_name)) {
+		if (!posix_xattr_acl(xattr_name))
+			return 0;
+		evm_status = evm_verify_current_integrity(dentry);
+		if ((evm_status == INTEGRITY_PASS) ||
+		    (evm_status == INTEGRITY_NOXATTRS))
+			return 0;
+		return -EPERM;
+	}
+	evm_status = evm_verify_current_integrity(dentry);
+	return evm_status == INTEGRITY_PASS ? 0 : -EPERM;
+}
+
+/**
+ * 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
+ *
+ * Updating 'security.evm' requires CAP_SYS_ADMIN privileges and that
+ * the current value is valid.
+ */
+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
+ *
+ * Removing 'security.evm' requires CAP_SYS_ADMIN privileges and that
+ * the current value is valid.
+ */
+int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+	return evm_protect_xattr(dentry, xattr_name, NULL, 0);
+}
+
+/**
+ * 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.
+ *
+ * No need to take the i_mutex lock here, as this function is called from
+ * __vfs_setxattr_noperm().  The caller of which has taken the inode's
+ * i_mutex lock.
+ */
+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)
+				 && !posix_xattr_acl(xattr_name)))
+		return;
+
+	evm_update_evmxattr(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)
+{
+	struct inode *inode = dentry->d_inode;
+
+	if (!evm_initialized || !evm_protected_xattr(xattr_name))
+		return;
+
+	mutex_lock(&inode->i_mutex);
+	evm_update_evmxattr(dentry, xattr_name, NULL, 0);
+	mutex_unlock(&inode->i_mutex);
+	return;
+}
+
+/**
+ * evm_inode_setattr - prevent updating an invalid EVM extended attribute
+ * @dentry: pointer to the affected dentry
+ */
+int evm_inode_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	unsigned int ia_valid = attr->ia_valid;
+	enum integrity_status evm_status;
+
+	if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))
+		return 0;
+	evm_status = evm_verify_current_integrity(dentry);
+	if ((evm_status == INTEGRITY_PASS) ||
+	    (evm_status == INTEGRITY_NOXATTRS))
+		return 0;
+	return -EPERM;
+}
+
+/**
+ * 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.
+ *
+ * This function is called from notify_change(), which expects the caller
+ * to lock the inode's i_mutex.
+ */
+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_update_evmxattr(dentry, NULL, NULL, 0);
+	return;
+}
+
+/*
+ * evm_inode_init_security - initializes security.evm
+ */
+int evm_inode_init_security(struct inode *inode,
+				 const struct xattr *lsm_xattr,
+				 struct xattr *evm_xattr)
+{
+	struct evm_ima_xattr_data *xattr_data;
+	int rc;
+
+	if (!evm_initialized || !evm_protected_xattr(lsm_xattr->name))
+		return 0;
+
+	xattr_data = kzalloc(sizeof(*xattr_data), GFP_NOFS);
+	if (!xattr_data)
+		return -ENOMEM;
+
+	xattr_data->type = EVM_XATTR_HMAC;
+	rc = evm_init_hmac(inode, lsm_xattr, xattr_data->digest);
+	if (rc < 0)
+		goto out;
+
+	evm_xattr->value = xattr_data;
+	evm_xattr->value_len = sizeof(*xattr_data);
+	evm_xattr->name = kstrdup(XATTR_EVM_SUFFIX, GFP_NOFS);
+	return 0;
+out:
+	kfree(xattr_data);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(evm_inode_init_security);
+
+static int __init init_evm(void)
+{
+	int error;
+
+	error = evm_init_secfs();
+	if (error < 0) {
+		printk(KERN_INFO "EVM: Error registering secfs\n");
+		goto err;
+	}
+
+	return 0;
+err:
+	return error;
+}
+
+/*
+ * 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");

security/integrity/evm/evm_posix_acl.c

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+#include <linux/module.h>
+#include <linux/xattr.h>
+
+int posix_xattr_acl(char *xattr)
+{
+	int xattr_len = strlen(xattr);
+
+	if ((strlen(XATTR_NAME_POSIX_ACL_ACCESS) == xattr_len)
+	     && (strncmp(XATTR_NAME_POSIX_ACL_ACCESS, xattr, xattr_len) == 0))
+		return 1;
+	if ((strlen(XATTR_NAME_POSIX_ACL_DEFAULT) == xattr_len)
+	     && (strncmp(XATTR_NAME_POSIX_ACL_DEFAULT, xattr, xattr_len) == 0))
+		return 1;
+	return 0;
+}

security/integrity/evm/evm_secfs.c

@@ -0,0 +1,102 @@
+/*
+ * 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_SYS_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_key();
+	if (!error) {
+		evm_initialized = 1;
+		pr_info("EVM: initialized\n");
+	} else
+		pr_err("EVM: initialization failed\n");
+	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;
+}

security/integrity/iint.c

@@ -0,0 +1,170 @@
+/*
+ * 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: integrity_iint.c
+ *	- implements the integrity hooks: integrity_inode_alloc,
+ *	  integrity_inode_free
+ *	- cache integrity information associated with an inode
+ *	  using a rbtree tree.
+ */
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/rbtree.h>
+#include "integrity.h"
+
+static struct rb_root integrity_iint_tree = RB_ROOT;
+static DEFINE_RWLOCK(integrity_iint_lock);
+static struct kmem_cache *iint_cache __read_mostly;
+
+int iint_initialized;
+
+/*
+ * __integrity_iint_find - return the iint associated with an inode
+ */
+static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode)
+{
+	struct integrity_iint_cache *iint;
+	struct rb_node *n = integrity_iint_tree.rb_node;
+
+	while (n) {
+		iint = rb_entry(n, struct integrity_iint_cache, rb_node);
+
+		if (inode < iint->inode)
+			n = n->rb_left;
+		else if (inode > iint->inode)
+			n = n->rb_right;
+		else
+			break;
+	}
+	if (!n)
+		return NULL;
+
+	return iint;
+}
+
+/*
+ * integrity_iint_find - return the iint associated with an inode
+ */
+struct integrity_iint_cache *integrity_iint_find(struct inode *inode)
+{
+	struct integrity_iint_cache *iint;
+
+	if (!IS_IMA(inode))
+		return NULL;
+
+	read_lock(&integrity_iint_lock);
+	iint = __integrity_iint_find(inode);
+	read_unlock(&integrity_iint_lock);
+
+	return iint;
+}
+
+static void iint_free(struct integrity_iint_cache *iint)
+{
+	iint->version = 0;
+	iint->flags = 0UL;
+	iint->ima_file_status = INTEGRITY_UNKNOWN;
+	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
+	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
+	iint->ima_module_status = INTEGRITY_UNKNOWN;
+	iint->evm_status = INTEGRITY_UNKNOWN;
+	kmem_cache_free(iint_cache, iint);
+}
+
+/**
+ * integrity_inode_get - find or allocate an iint associated with an inode
+ * @inode: pointer to the inode
+ * @return: allocated iint
+ *
+ * Caller must lock i_mutex
+ */
+struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
+{
+	struct rb_node **p;
+	struct rb_node *node, *parent = NULL;
+	struct integrity_iint_cache *iint, *test_iint;
+
+	iint = integrity_iint_find(inode);
+	if (iint)
+		return iint;
+
+	iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
+	if (!iint)
+		return NULL;
+
+	write_lock(&integrity_iint_lock);
+
+	p = &integrity_iint_tree.rb_node;
+	while (*p) {
+		parent = *p;
+		test_iint = rb_entry(parent, struct integrity_iint_cache,
+				     rb_node);
+		if (inode < test_iint->inode)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	iint->inode = inode;
+	node = &iint->rb_node;
+	inode->i_flags |= S_IMA;
+	rb_link_node(node, parent, p);
+	rb_insert_color(node, &integrity_iint_tree);
+
+	write_unlock(&integrity_iint_lock);
+	return iint;
+}
+
+/**
+ * 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;
+
+	if (!IS_IMA(inode))
+		return;
+
+	write_lock(&integrity_iint_lock);
+	iint = __integrity_iint_find(inode);
+	rb_erase(&iint->rb_node, &integrity_iint_tree);
+	write_unlock(&integrity_iint_lock);
+
+	iint_free(iint);
+}
+
+static void init_once(void *foo)
+{
+	struct integrity_iint_cache *iint = foo;
+
+	memset(iint, 0, sizeof *iint);
+	iint->version = 0;
+	iint->flags = 0UL;
+	iint->ima_file_status = INTEGRITY_UNKNOWN;
+	iint->ima_mmap_status = INTEGRITY_UNKNOWN;
+	iint->ima_bprm_status = INTEGRITY_UNKNOWN;
+	iint->ima_module_status = INTEGRITY_UNKNOWN;
+	iint->evm_status = INTEGRITY_UNKNOWN;
+}
+
+static int __init integrity_iintcache_init(void)
+{
+	iint_cache =
+	    kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
+			      0, SLAB_PANIC, init_once);
+	iint_initialized = 1;
+	return 0;
+}
+security_initcall(integrity_iintcache_init);

security/integrity/ima/Kconfig

@@ -0,0 +1,73 @@
+# IBM Integrity Measurement Architecture
+#
+config IMA
+	bool "Integrity Measurement Architecture(IMA)"
+	depends on SECURITY
+	select INTEGRITY
+	select SECURITYFS
+	select CRYPTO
+	select CRYPTO_HMAC
+	select CRYPTO_MD5
+	select CRYPTO_SHA1
+	select TCG_TPM if HAS_IOMEM && !UML
+	select TCG_TIS if TCG_TPM && X86
+	select TCG_IBMVTPM if TCG_TPM && PPC64
+	help
+	  The Trusted Computing Group(TCG) runtime Integrity
+	  Measurement Architecture(IMA) maintains a list of hash
+	  values of executables and other sensitive system files,
+	  as they are read or executed. If an attacker manages
+	  to change the contents of an important system file
+	  being measured, we can tell.
+
+	  If your system has a TPM chip, then IMA also maintains
+	  an aggregate integrity value over this list inside the
+	  TPM hardware, so that the TPM can prove to a third party
+	  whether or not critical system files have been modified.
+	  Read <http://www.usenix.org/events/sec04/tech/sailer.html>
+	  to learn more about IMA.
+	  If unsure, say N.
+
+config IMA_MEASURE_PCR_IDX
+	int
+	depends on IMA
+	range 8 14
+	default 10
+	help
+	  IMA_MEASURE_PCR_IDX determines the TPM PCR register index
+	  that IMA uses to maintain the integrity aggregate of the
+	  measurement list.  If unsure, use the default 10.
+
+config IMA_AUDIT
+	bool "Enables auditing support"
+	depends on IMA
+	depends on AUDIT
+	default y
+	help
+	  This option adds a kernel parameter 'ima_audit', which
+	  allows informational auditing messages to be enabled
+	  at boot.  If this option is selected, informational integrity
+	  auditing messages can be enabled with 'ima_audit=1' on
+	  the kernel command line.
+
+config IMA_LSM_RULES
+	bool
+	depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
+	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.

security/integrity/ima/Makefile

@@ -0,0 +1,11 @@
+#
+# Makefile for building Trusted Computing Group's(TCG) runtime Integrity
+# Measurement Architecture(IMA).
+#
+
+obj-$(CONFIG_IMA) += ima.o
+
+ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
+	 ima_policy.o
+ima-$(CONFIG_IMA_AUDIT) += ima_audit.o
+ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o

security/integrity/ima/ima.h

@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * 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.h
+ *	internal Integrity Measurement Architecture (IMA) definitions
+ */
+
+#ifndef __LINUX_IMA_H
+#define __LINUX_IMA_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/security.h>
+#include <linux/hash.h>
+#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		SHA1_DIGEST_SIZE
+#define IMA_EVENT_NAME_LEN_MAX	255
+
+#define IMA_HASH_BITS 9
+#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
+
+/* set during initialization */
+extern int ima_initialized;
+extern int ima_used_chip;
+extern char *ima_hash;
+extern int ima_appraise;
+
+/* IMA inode template definition */
+struct ima_template_data {
+	u8 digest[IMA_DIGEST_SIZE];	/* sha1/md5 measurement hash */
+	char file_name[IMA_EVENT_NAME_LEN_MAX + 1];	/* name + \0 */
+};
+
+struct ima_template_entry {
+	u8 digest[IMA_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
+	const char *template_name;
+	int template_len;
+	struct ima_template_data template;
+};
+
+struct ima_queue_entry {
+	struct hlist_node hnext;	/* place in hash collision list */
+	struct list_head later;		/* place in ima_measurements list */
+	struct ima_template_entry *entry;
+};
+extern struct list_head ima_measurements;	/* list of all measurements */
+
+#ifdef CONFIG_IMA_AUDIT
+/* declarations */
+void integrity_audit_msg(int audit_msgno, struct inode *inode,
+			 const unsigned char *fname, const char *op,
+			 const char *cause, int result, int info);
+#else
+static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
+				       const unsigned char *fname,
+				       const char *op, const char *cause,
+				       int result, int info)
+{
+}
+#endif
+
+/* Internal IMA function definitions */
+int ima_init(void);
+void ima_cleanup(void);
+int ima_fs_init(void);
+void ima_fs_cleanup(void);
+int ima_inode_alloc(struct inode *inode);
+int ima_add_template_entry(struct ima_template_entry *entry, int violation,
+			   const char *op, struct inode *inode);
+int ima_calc_file_hash(struct file *file, char *digest);
+int ima_calc_buffer_hash(const void *data, int len, char *digest);
+int ima_calc_boot_aggregate(char *digest);
+void ima_add_violation(struct inode *inode, const unsigned char *filename,
+		       const char *op, const char *cause);
+int ima_init_crypto(void);
+
+/*
+ * used to protect h_table and sha_table
+ */
+extern spinlock_t ima_queue_lock;
+
+struct ima_h_table {
+	atomic_long_t len;	/* number of stored measurements in the list */
+	atomic_long_t violations;
+	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
+};
+extern struct ima_h_table ima_htable;
+
+static inline unsigned long ima_hash_key(u8 *digest)
+{
+	return hash_long(*digest, IMA_HASH_BITS);
+}
+
+/* LIM API function definitions */
+int ima_get_action(struct inode *inode, int mask, int function);
+int ima_must_measure(struct inode *inode, int mask, int function);
+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);
+void ima_audit_measurement(struct integrity_iint_cache *iint,
+			   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);
+const char *ima_d_path(struct path *path, char **pathbuf);
+
+/* rbtree 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(struct inode *inode);
+
+/* IMA policy related functions */
+enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, POST_SETATTR };
+
+int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
+		     int flags);
+void ima_init_policy(void);
+void ima_update_policy(void);
+ssize_t ima_parse_add_rule(char *);
+void ima_delete_rules(void);
+
+/* Appraise integrity measurements */
+#define IMA_APPRAISE_ENFORCE	0x01
+#define IMA_APPRAISE_FIX	0x02
+#define IMA_APPRAISE_MODULES	0x04
+
+#ifdef CONFIG_IMA_APPRAISE
+int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
+			     struct file *file, const unsigned char *filename);
+int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
+void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
+enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
+					   int func);
+
+#else
+static inline int ima_appraise_measurement(int func,
+					   struct integrity_iint_cache *iint,
+					   struct file *file,
+					   const unsigned char *filename)
+{
+	return INTEGRITY_UNKNOWN;
+}
+
+static inline int ima_must_appraise(struct inode *inode, int mask,
+				    enum ima_hooks func)
+{
+	return 0;
+}
+
+static inline void ima_update_xattr(struct integrity_iint_cache *iint,
+				    struct file *file)
+{
+}
+
+static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
+							 *iint, int func)
+{
+	return INTEGRITY_UNKNOWN;
+}
+#endif
+
+/* LSM based policy rules require audit */
+#ifdef CONFIG_IMA_LSM_RULES
+
+#define security_filter_rule_init security_audit_rule_init
+#define security_filter_rule_match security_audit_rule_match
+
+#else
+
+static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
+					    void **lsmrule)
+{
+	return -EINVAL;
+}
+
+static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
+					     void *lsmrule,
+					     struct audit_context *actx)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_IMA_LSM_RULES */
+#endif

security/integrity/ima/ima_api.c

@@ -0,0 +1,256 @@
+/*
+ * Copyright (C) 2008 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.
+ *
+ * File: ima_api.c
+ *	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";
+
+/*
+ * ima_store_template - store ima template measurements
+ *
+ * Calculate the hash of a template entry, add the template entry
+ * to an ordered list of measurement entries maintained inside the kernel,
+ * and also update the aggregate integrity value (maintained inside the
+ * configured TPM PCR) over the hashes of the current list of measurement
+ * entries.
+ *
+ * Applications retrieve the current kernel-held measurement list through
+ * the securityfs entries in /sys/kernel/security/ima. The signed aggregate
+ * TPM PCR (called quote) can be retrieved using a TPM user space library
+ * and is used to validate the measurement list.
+ *
+ * Returns 0 on success, error code otherwise
+ */
+int ima_store_template(struct ima_template_entry *entry,
+		       int violation, struct inode *inode)
+{
+	const char *op = "add_template_measure";
+	const char *audit_cause = "hashing_error";
+	int result;
+
+	memset(entry->digest, 0, sizeof(entry->digest));
+	entry->template_name = IMA_TEMPLATE_NAME;
+	entry->template_len = sizeof(entry->template);
+
+	if (!violation) {
+		result = ima_calc_buffer_hash(&entry->template,
+						entry->template_len,
+						entry->digest);
+		if (result < 0) {
+			integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
+					    entry->template_name, op,
+					    audit_cause, result, 0);
+			return result;
+		}
+	}
+	result = ima_add_template_entry(entry, violation, op, inode);
+	return result;
+}
+
+/*
+ * ima_add_violation - add violation to measurement list.
+ *
+ * Violations are flagged in the measurement list with zero hash values.
+ * By extending the PCR with 0xFF's instead of with zeroes, the PCR
+ * value is invalidated.
+ */
+void ima_add_violation(struct inode *inode, const unsigned char *filename,
+		       const char *op, const char *cause)
+{
+	struct ima_template_entry *entry;
+	int violation = 1;
+	int result;
+
+	/* can overflow, only indicator */
+	atomic_long_inc(&ima_htable.violations);
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry) {
+		result = -ENOMEM;
+		goto err_out;
+	}
+	memset(&entry->template, 0, sizeof(entry->template));
+	strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);
+	result = ima_store_template(entry, violation, inode);
+	if (result < 0)
+		kfree(entry);
+err_out:
+	integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
+			    op, cause, result, 0);
+}
+
+/**
+ * ima_get_action - 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, MMAP_CHECK, MODULE_CHECK)
+ *
+ * The policy is defined in terms of keypairs:
+ * 		subj=, obj=, type=, func=, mask=, fsmagic=
+ *	subj,obj, and type: are LSM specific.
+ * 	func: FILE_CHECK | BPRM_CHECK | MMAP_CHECK | MODULE_CHECK
+ * 	mask: contains the permission mask
+ *	fsmagic: hex value
+ *
+ * Returns IMA_MEASURE, IMA_APPRAISE mask.
+ *
+ */
+int ima_get_action(struct inode *inode, int mask, int function)
+{
+	int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE;
+
+	if (!ima_appraise)
+		flags &= ~IMA_APPRAISE;
+
+	return ima_match_policy(inode, function, mask, flags);
+}
+
+int ima_must_measure(struct inode *inode, int mask, int function)
+{
+	return ima_match_policy(inode, function, mask, IMA_MEASURE);
+}
+
+/*
+ * ima_collect_measurement - collect file measurement
+ *
+ * Calculate the file hash, if it doesn't already exist,
+ * storing the measurement and i_version in the iint.
+ *
+ * Must be called with iint->mutex held.
+ *
+ * Return 0 on success, error code otherwise
+ */
+int ima_collect_measurement(struct integrity_iint_cache *iint,
+			    struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	const char *filename = file->f_dentry->d_name.name;
+	int result = 0;
+
+	if (!(iint->flags & IMA_COLLECTED)) {
+		u64 i_version = file_inode(file)->i_version;
+
+		iint->ima_xattr.type = IMA_XATTR_DIGEST;
+		result = ima_calc_file_hash(file, iint->ima_xattr.digest);
+		if (!result) {
+			iint->version = i_version;
+			iint->flags |= IMA_COLLECTED;
+		}
+	}
+	if (result)
+		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
+				    filename, "collect_data", "failed",
+				    result, 0);
+	return result;
+}
+
+/*
+ * ima_store_measurement - store file measurement
+ *
+ * Create an "ima" template and then store the template by calling
+ * ima_store_template.
+ *
+ * We only get here if the inode has not already been measured,
+ * but the measurement could already exist:
+ * 	- multiple copies of the same file on either the same or
+ *	  different filesystems.
+ *	- the inode was previously flushed as well as the iint info,
+ *	  containing the hashing info.
+ *
+ * Must be called with iint->mutex held.
+ */
+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";
+	int result = -ENOMEM;
+	struct inode *inode = file_inode(file);
+	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,
+				    op, audit_cause, result, 0);
+		return;
+	}
+	memset(&entry->template, 0, sizeof(entry->template));
+	memcpy(entry->template.digest, iint->ima_xattr.digest, IMA_DIGEST_SIZE);
+	strcpy(entry->template.file_name,
+	       (strlen(filename) > IMA_EVENT_NAME_LEN_MAX) ?
+	       file->f_dentry->d_name.name : filename);
+
+	result = ima_store_template(entry, violation, inode);
+	if (!result || result == -EEXIST)
+		iint->flags |= IMA_MEASURED;
+	if (result < 0)
+		kfree(entry);
+}
+
+void ima_audit_measurement(struct integrity_iint_cache *iint,
+			   const unsigned char *filename)
+{
+	struct audit_buffer *ab;
+	char hash[(IMA_DIGEST_SIZE * 2) + 1];
+	int i;
+
+	if (iint->flags & IMA_AUDITED)
+		return;
+
+	for (i = 0; i < IMA_DIGEST_SIZE; i++)
+		hex_byte_pack(hash + (i * 2), iint->ima_xattr.digest[i]);
+	hash[i * 2] = '\0';
+
+	ab = audit_log_start(current->audit_context, GFP_KERNEL,
+			     AUDIT_INTEGRITY_RULE);
+	if (!ab)
+		return;
+
+	audit_log_format(ab, "file=");
+	audit_log_untrustedstring(ab, filename);
+	audit_log_format(ab, " hash=");
+	audit_log_untrustedstring(ab, hash);
+
+	audit_log_task_info(ab, current);
+	audit_log_end(ab);
+
+	iint->flags |= IMA_AUDITED;
+}
+
+const char *ima_d_path(struct path *path, char **pathbuf)
+{
+	char *pathname = NULL;
+
+	/* We will allow 11 spaces for ' (deleted)' to be appended */
+	*pathbuf = kmalloc(PATH_MAX + 11, GFP_KERNEL);
+	if (*pathbuf) {
+		pathname = d_path(path, *pathbuf, PATH_MAX + 11);
+		if (IS_ERR(pathname)) {
+			kfree(*pathbuf);
+			*pathbuf = NULL;
+			pathname = NULL;
+		}
+	}
+	return pathname;
+}

security/integrity/ima/ima_appraise.c

@@ -0,0 +1,317 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/xattr.h>
+#include <linux/magic.h>
+#include <linux/ima.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, "fix", 3) == 0)
+		ima_appraise = 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 inode *inode, int mask, enum ima_hooks func)
+{
+	if (!ima_appraise)
+		return 0;
+
+	return ima_match_policy(inode, func, mask, IMA_APPRAISE);
+}
+
+static int ima_fix_xattr(struct dentry *dentry,
+			  struct integrity_iint_cache *iint)
+{
+	iint->ima_xattr.type = IMA_XATTR_DIGEST;
+	return __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
+				     (u8 *)&iint->ima_xattr,
+				      sizeof(iint->ima_xattr), 0);
+}
+
+/* Return specific func appraised cached result */
+enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
+					   int func)
+{
+	switch(func) {
+	case MMAP_CHECK:
+		return iint->ima_mmap_status;
+	case BPRM_CHECK:
+		return iint->ima_bprm_status;
+	case MODULE_CHECK:
+		return iint->ima_module_status;
+	case FILE_CHECK:
+	default:
+		return iint->ima_file_status;
+	}
+}
+
+static void ima_set_cache_status(struct integrity_iint_cache *iint,
+				 int func, enum integrity_status status)
+{
+	switch(func) {
+	case MMAP_CHECK:
+		iint->ima_mmap_status = status;
+		break;
+	case BPRM_CHECK:
+		iint->ima_bprm_status = status;
+		break;
+	case MODULE_CHECK:
+		iint->ima_module_status = status;
+		break;
+	case FILE_CHECK:
+	default:
+		iint->ima_file_status = status;
+		break;
+	}
+}
+
+static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
+{
+	switch(func) {
+	case MMAP_CHECK:
+		iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED);
+		break;
+	case BPRM_CHECK:
+		iint->flags |= (IMA_BPRM_APPRAISED | IMA_APPRAISED);
+		break;
+	case MODULE_CHECK:
+		iint->flags |= (IMA_MODULE_APPRAISED | IMA_APPRAISED);
+		break;
+	case FILE_CHECK:
+	default:
+		iint->flags |= (IMA_FILE_APPRAISED | IMA_APPRAISED);
+		break;
+	}
+}
+
+/*
+ * 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(int func, struct integrity_iint_cache *iint,
+			     struct file *file, const unsigned char *filename)
+{
+	struct dentry *dentry = file->f_dentry;
+	struct inode *inode = dentry->d_inode;
+	struct evm_ima_xattr_data *xattr_value = NULL;
+	enum integrity_status status = INTEGRITY_UNKNOWN;
+	const char *op = "appraise_data";
+	char *cause = "unknown";
+	int rc;
+
+	if (!ima_appraise)
+		return 0;
+	if (!inode->i_op->getxattr)
+		return INTEGRITY_UNKNOWN;
+
+	rc = vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)&xattr_value,
+				0, GFP_NOFS);
+	if (rc <= 0) {
+		if (rc && rc != -ENODATA)
+			goto out;
+
+		cause = "missing-hash";
+		status =
+		    (inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL;
+		goto out;
+	}
+
+	status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint);
+	if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) {
+		if ((status == INTEGRITY_NOLABEL)
+		    || (status == INTEGRITY_NOXATTRS))
+			cause = "missing-HMAC";
+		else if (status == INTEGRITY_FAIL)
+			cause = "invalid-HMAC";
+		goto out;
+	}
+	switch (xattr_value->type) {
+	case IMA_XATTR_DIGEST:
+		if (iint->flags & IMA_DIGSIG_REQUIRED) {
+			cause = "IMA signature required";
+			status = INTEGRITY_FAIL;
+			break;
+		}
+		rc = memcmp(xattr_value->digest, iint->ima_xattr.digest,
+			    IMA_DIGEST_SIZE);
+		if (rc) {
+			cause = "invalid-hash";
+			status = INTEGRITY_FAIL;
+			break;
+		}
+		status = INTEGRITY_PASS;
+		break;
+	case EVM_IMA_XATTR_DIGSIG:
+		iint->flags |= IMA_DIGSIG;
+		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
+					     xattr_value->digest, rc - 1,
+					     iint->ima_xattr.digest,
+					     IMA_DIGEST_SIZE);
+		if (rc == -EOPNOTSUPP) {
+			status = INTEGRITY_UNKNOWN;
+		} else if (rc) {
+			cause = "invalid-signature";
+			status = INTEGRITY_FAIL;
+		} else {
+			status = INTEGRITY_PASS;
+		}
+		break;
+	default:
+		status = INTEGRITY_UNKNOWN;
+		cause = "unknown-ima-data";
+		break;
+	}
+
+out:
+	if (status != INTEGRITY_PASS) {
+		if ((ima_appraise & IMA_APPRAISE_FIX) &&
+		    (!xattr_value ||
+		     xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
+			if (!ima_fix_xattr(dentry, iint))
+				status = INTEGRITY_PASS;
+		}
+		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+				    op, cause, rc, 0);
+	} else {
+		ima_cache_flags(iint, func);
+	}
+	ima_set_cache_status(iint, func, status);
+	kfree(xattr_value);
+	return status;
+}
+
+/*
+ * 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 rc = 0;
+
+	/* do not collect and update hash for digital signatures */
+	if (iint->flags & IMA_DIGSIG)
+		return;
+
+	rc = ima_collect_measurement(iint, file);
+	if (rc < 0)
+		return;
+
+	ima_fix_xattr(dentry, iint);
+}
+
+/**
+ * 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.
+ *
+ * This function is called from notify_change(), which expects the caller
+ * to lock the inode's i_mutex.
+ */
+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;
+
+	must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR);
+	iint = integrity_iint_find(inode);
+	if (iint) {
+		iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
+				 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
+				 IMA_ACTION_FLAGS);
+		if (must_appraise)
+			iint->flags |= IMA_APPRAISE;
+	}
+	if (!must_appraise)
+		rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA);
+	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) {
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		return 1;
+	}
+	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(inode);
+	if (!iint)
+		return;
+
+	iint->flags &= ~IMA_DONE_MASK;
+	return;
+}
+
+int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+		       const void *xattr_value, size_t xattr_value_len)
+{
+	int result;
+
+	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
+				   xattr_value_len);
+	if (result == 1) {
+		ima_reset_appraise_flags(dentry->d_inode);
+		result = 0;
+	}
+	return result;
+}
+
+int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+{
+	int result;
+
+	result = ima_protect_xattr(dentry, xattr_name, NULL, 0);
+	if (result == 1) {
+		ima_reset_appraise_flags(dentry->d_inode);
+		result = 0;
+	}
+	return result;
+}

security/integrity/ima/ima_audit.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2008 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.
+ *
+ * File: integrity_audit.c
+ * 	Audit calls for the integrity subsystem
+ */
+
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/audit.h>
+#include "ima.h"
+
+static int ima_audit;
+
+/* ima_audit_setup - enable informational auditing messages */
+static int __init ima_audit_setup(char *str)
+{
+	unsigned long audit;
+
+	if (!strict_strtoul(str, 0, &audit))
+		ima_audit = audit ? 1 : 0;
+	return 1;
+}
+__setup("ima_audit=", ima_audit_setup);
+
+void integrity_audit_msg(int audit_msgno, struct inode *inode,
+			 const unsigned char *fname, const char *op,
+			 const char *cause, int result, int audit_info)
+{
+	struct audit_buffer *ab;
+
+	if (!ima_audit && audit_info == 1) /* Skip informational messages */
+		return;
+
+	ab = audit_log_start(current->audit_context, GFP_KERNEL, audit_msgno);
+	audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u",
+			 current->pid,
+			 from_kuid(&init_user_ns, current_cred()->uid),
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 audit_get_sessionid(current));
+	audit_log_task_context(ab);
+	audit_log_format(ab, " op=");
+	audit_log_string(ab, op);
+	audit_log_format(ab, " cause=");
+	audit_log_string(ab, cause);
+	audit_log_format(ab, " comm=");
+	audit_log_untrustedstring(ab, current->comm);
+	if (fname) {
+		audit_log_format(ab, " name=");
+		audit_log_untrustedstring(ab, fname);
+	}
+	if (inode) {
+		audit_log_format(ab, " dev=");
+		audit_log_untrustedstring(ab, inode->i_sb->s_id);
+		audit_log_format(ab, " ino=%lu", inode->i_ino);
+	}
+	audit_log_format(ab, " res=%d", !result);
+	audit_log_end(ab);
+}

security/integrity/ima/ima_crypto.c

@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 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: ima_crypto.c
+ * 	Calculates md5/sha1 file hash, template hash, boot-aggreate hash
+ */
+
+#include <linux/kernel.h>
+#include <linux/file.h>
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <crypto/hash.h>
+#include "ima.h"
+
+static struct crypto_shash *ima_shash_tfm;
+
+int ima_init_crypto(void)
+{
+	long rc;
+
+	ima_shash_tfm = crypto_alloc_shash(ima_hash, 0, 0);
+	if (IS_ERR(ima_shash_tfm)) {
+		rc = PTR_ERR(ima_shash_tfm);
+		pr_err("Can not allocate %s (reason: %ld)\n", ima_hash, rc);
+		return rc;
+	}
+	return 0;
+}
+
+/*
+ * Calculate the MD5/SHA1 file digest
+ */
+int ima_calc_file_hash(struct file *file, char *digest)
+{
+	loff_t i_size, offset = 0;
+	char *rbuf;
+	int rc, read = 0;
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(ima_shash_tfm)];
+	} desc;
+
+	desc.shash.tfm = ima_shash_tfm;
+	desc.shash.flags = 0;
+
+	rc = crypto_shash_init(&desc.shash);
+	if (rc != 0)
+		return rc;
+
+	rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!rbuf) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	if (!(file->f_mode & FMODE_READ)) {
+		file->f_mode |= FMODE_READ;
+		read = 1;
+	}
+	i_size = i_size_read(file_inode(file));
+	while (offset < i_size) {
+		int rbuf_len;
+
+		rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
+		if (rbuf_len < 0) {
+			rc = rbuf_len;
+			break;
+		}
+		if (rbuf_len == 0)
+			break;
+		offset += rbuf_len;
+
+		rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len);
+		if (rc)
+			break;
+	}
+	kfree(rbuf);
+	if (!rc)
+		rc = crypto_shash_final(&desc.shash, digest);
+	if (read)
+		file->f_mode &= ~FMODE_READ;
+out:
+	return rc;
+}
+
+/*
+ * Calculate the hash of a given buffer
+ */
+int ima_calc_buffer_hash(const void *data, int len, char *digest)
+{
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(ima_shash_tfm)];
+	} desc;
+
+	desc.shash.tfm = ima_shash_tfm;
+	desc.shash.flags = 0;
+
+	return crypto_shash_digest(&desc.shash, data, len, digest);
+}
+
+static void __init ima_pcrread(int idx, u8 *pcr)
+{
+	if (!ima_used_chip)
+		return;
+
+	if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
+		pr_err("IMA: Error Communicating to TPM chip\n");
+}
+
+/*
+ * Calculate the boot aggregate hash
+ */
+int __init ima_calc_boot_aggregate(char *digest)
+{
+	u8 pcr_i[IMA_DIGEST_SIZE];
+	int rc, i;
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(ima_shash_tfm)];
+	} desc;
+
+	desc.shash.tfm = ima_shash_tfm;
+	desc.shash.flags = 0;
+
+	rc = crypto_shash_init(&desc.shash);
+	if (rc != 0)
+		return rc;
+
+	/* cumulative sha1 over tpm registers 0-7 */
+	for (i = TPM_PCR0; i < TPM_PCR8; i++) {
+		ima_pcrread(i, pcr_i);
+		/* now accumulate with current aggregate */
+		rc = crypto_shash_update(&desc.shash, pcr_i, IMA_DIGEST_SIZE);
+	}
+	if (!rc)
+		crypto_shash_final(&desc.shash, digest);
+	return rc;
+}

security/integrity/ima/ima_fs.c

@@ -0,0 +1,377 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Kylene Hall <kjhall@us.ibm.com>
+ * Reiner Sailer <sailer@us.ibm.com>
+ * 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_fs.c
+ *	implemenents security file system for reporting
+ *	current measurement list and IMA statistics
+ */
+#include <linux/fcntl.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/parser.h>
+
+#include "ima.h"
+
+static int valid_policy = 1;
+#define TMPBUFLEN 12
+static ssize_t ima_show_htable_value(char __user *buf, size_t count,
+				     loff_t *ppos, atomic_long_t *val)
+{
+	char tmpbuf[TMPBUFLEN];
+	ssize_t len;
+
+	len = scnprintf(tmpbuf, TMPBUFLEN, "%li\n", atomic_long_read(val));
+	return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
+}
+
+static ssize_t ima_show_htable_violations(struct file *filp,
+					  char __user *buf,
+					  size_t count, loff_t *ppos)
+{
+	return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
+}
+
+static const struct file_operations ima_htable_violations_ops = {
+	.read = ima_show_htable_violations,
+	.llseek = generic_file_llseek,
+};
+
+static ssize_t ima_show_measurements_count(struct file *filp,
+					   char __user *buf,
+					   size_t count, loff_t *ppos)
+{
+	return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
+
+}
+
+static const struct file_operations ima_measurements_count_ops = {
+	.read = ima_show_measurements_count,
+	.llseek = generic_file_llseek,
+};
+
+/* returns pointer to hlist_node */
+static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t l = *pos;
+	struct ima_queue_entry *qe;
+
+	/* we need a lock since pos could point beyond last element */
+	rcu_read_lock();
+	list_for_each_entry_rcu(qe, &ima_measurements, later) {
+		if (!l--) {
+			rcu_read_unlock();
+			return qe;
+		}
+	}
+	rcu_read_unlock();
+	return NULL;
+}
+
+static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct ima_queue_entry *qe = v;
+
+	/* lock protects when reading beyond last element
+	 * against concurrent list-extension
+	 */
+	rcu_read_lock();
+	qe = list_entry_rcu(qe->later.next,
+			    struct ima_queue_entry, later);
+	rcu_read_unlock();
+	(*pos)++;
+
+	return (&qe->later == &ima_measurements) ? NULL : qe;
+}
+
+static void ima_measurements_stop(struct seq_file *m, void *v)
+{
+}
+
+static void ima_putc(struct seq_file *m, void *data, int datalen)
+{
+	while (datalen--)
+		seq_putc(m, *(char *)data++);
+}
+
+/* print format:
+ *       32bit-le=pcr#
+ *       char[20]=template digest
+ *       32bit-le=template name size
+ *       char[n]=template name
+ *       eventdata[n]=template specific data
+ */
+static int ima_measurements_show(struct seq_file *m, void *v)
+{
+	/* the list never shrinks, so we don't need a lock here */
+	struct ima_queue_entry *qe = v;
+	struct ima_template_entry *e;
+	int namelen;
+	u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+
+	/* get entry */
+	e = qe->entry;
+	if (e == NULL)
+		return -1;
+
+	/*
+	 * 1st: PCRIndex
+	 * PCR used is always the same (config option) in
+	 * little-endian format
+	 */
+	ima_putc(m, &pcr, sizeof pcr);
+
+	/* 2nd: template digest */
+	ima_putc(m, e->digest, IMA_DIGEST_SIZE);
+
+	/* 3rd: template name size */
+	namelen = strlen(e->template_name);
+	ima_putc(m, &namelen, sizeof namelen);
+
+	/* 4th:  template name */
+	ima_putc(m, (void *)e->template_name, namelen);
+
+	/* 5th:  template specific data */
+	ima_template_show(m, (struct ima_template_data *)&e->template,
+			  IMA_SHOW_BINARY);
+	return 0;
+}
+
+static const struct seq_operations ima_measurments_seqops = {
+	.start = ima_measurements_start,
+	.next = ima_measurements_next,
+	.stop = ima_measurements_stop,
+	.show = ima_measurements_show
+};
+
+static int ima_measurements_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &ima_measurments_seqops);
+}
+
+static const struct file_operations ima_measurements_ops = {
+	.open = ima_measurements_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
+};
+
+static void ima_print_digest(struct seq_file *m, u8 *digest)
+{
+	int i;
+
+	for (i = 0; i < IMA_DIGEST_SIZE; i++)
+		seq_printf(m, "%02x", *(digest + i));
+}
+
+void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show)
+{
+	struct ima_template_data *entry = e;
+	int namelen;
+
+	switch (show) {
+	case IMA_SHOW_ASCII:
+		ima_print_digest(m, entry->digest);
+		seq_printf(m, " %s\n", entry->file_name);
+		break;
+	case IMA_SHOW_BINARY:
+		ima_putc(m, entry->digest, IMA_DIGEST_SIZE);
+
+		namelen = strlen(entry->file_name);
+		ima_putc(m, &namelen, sizeof namelen);
+		ima_putc(m, entry->file_name, namelen);
+	default:
+		break;
+	}
+}
+
+/* print in ascii */
+static int ima_ascii_measurements_show(struct seq_file *m, void *v)
+{
+	/* the list never shrinks, so we don't need a lock here */
+	struct ima_queue_entry *qe = v;
+	struct ima_template_entry *e;
+
+	/* get entry */
+	e = qe->entry;
+	if (e == NULL)
+		return -1;
+
+	/* 1st: PCR used (config option) */
+	seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
+
+	/* 2nd: SHA1 template hash */
+	ima_print_digest(m, e->digest);
+
+	/* 3th:  template name */
+	seq_printf(m, " %s ", e->template_name);
+
+	/* 4th:  template specific data */
+	ima_template_show(m, (struct ima_template_data *)&e->template,
+			  IMA_SHOW_ASCII);
+	return 0;
+}
+
+static const struct seq_operations ima_ascii_measurements_seqops = {
+	.start = ima_measurements_start,
+	.next = ima_measurements_next,
+	.stop = ima_measurements_stop,
+	.show = ima_ascii_measurements_show
+};
+
+static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &ima_ascii_measurements_seqops);
+}
+
+static const struct file_operations ima_ascii_measurements_ops = {
+	.open = ima_ascii_measurements_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
+};
+
+static ssize_t ima_write_policy(struct file *file, const char __user *buf,
+				size_t datalen, loff_t *ppos)
+{
+	char *data = NULL;
+	ssize_t result;
+
+	if (datalen >= PAGE_SIZE)
+		datalen = PAGE_SIZE - 1;
+
+	/* No partial writes. */
+	result = -EINVAL;
+	if (*ppos != 0)
+		goto out;
+
+	result = -ENOMEM;
+	data = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!data)
+		goto out;
+
+	*(data + datalen) = '\0';
+
+	result = -EFAULT;
+	if (copy_from_user(data, buf, datalen))
+		goto out;
+
+	result = ima_parse_add_rule(data);
+out:
+	if (result < 0)
+		valid_policy = 0;
+	kfree(data);
+	return result;
+}
+
+static struct dentry *ima_dir;
+static struct dentry *binary_runtime_measurements;
+static struct dentry *ascii_runtime_measurements;
+static struct dentry *runtime_measurements_count;
+static struct dentry *violations;
+static struct dentry *ima_policy;
+
+static atomic_t policy_opencount = ATOMIC_INIT(1);
+/*
+ * ima_open_policy: sequentialize access to the policy file
+ */
+static int ima_open_policy(struct inode * inode, struct file * filp)
+{
+	/* No point in being allowed to open it if you aren't going to write */
+	if (!(filp->f_flags & O_WRONLY))
+		return -EACCES;
+	if (atomic_dec_and_test(&policy_opencount))
+		return 0;
+	return -EBUSY;
+}
+
+/*
+ * ima_release_policy - start using the new measure policy rules.
+ *
+ * Initially, ima_measure points to the default policy rules, now
+ * point to the new policy rules, and remove the securityfs policy file,
+ * assuming a valid policy.
+ */
+static int ima_release_policy(struct inode *inode, struct file *file)
+{
+	if (!valid_policy) {
+		ima_delete_rules();
+		valid_policy = 1;
+		atomic_set(&policy_opencount, 1);
+		return 0;
+	}
+	ima_update_policy();
+	securityfs_remove(ima_policy);
+	ima_policy = NULL;
+	return 0;
+}
+
+static const struct file_operations ima_measure_policy_ops = {
+	.open = ima_open_policy,
+	.write = ima_write_policy,
+	.release = ima_release_policy,
+	.llseek = generic_file_llseek,
+};
+
+int __init ima_fs_init(void)
+{
+	ima_dir = securityfs_create_dir("ima", NULL);
+	if (IS_ERR(ima_dir))
+		return -1;
+
+	binary_runtime_measurements =
+	    securityfs_create_file("binary_runtime_measurements",
+				   S_IRUSR | S_IRGRP, ima_dir, NULL,
+				   &ima_measurements_ops);
+	if (IS_ERR(binary_runtime_measurements))
+		goto out;
+
+	ascii_runtime_measurements =
+	    securityfs_create_file("ascii_runtime_measurements",
+				   S_IRUSR | S_IRGRP, ima_dir, NULL,
+				   &ima_ascii_measurements_ops);
+	if (IS_ERR(ascii_runtime_measurements))
+		goto out;
+
+	runtime_measurements_count =
+	    securityfs_create_file("runtime_measurements_count",
+				   S_IRUSR | S_IRGRP, ima_dir, NULL,
+				   &ima_measurements_count_ops);
+	if (IS_ERR(runtime_measurements_count))
+		goto out;
+
+	violations =
+	    securityfs_create_file("violations", S_IRUSR | S_IRGRP,
+				   ima_dir, NULL, &ima_htable_violations_ops);
+	if (IS_ERR(violations))
+		goto out;
+
+	ima_policy = securityfs_create_file("policy",
+					    S_IWUSR,
+					    ima_dir, NULL,
+					    &ima_measure_policy_ops);
+	if (IS_ERR(ima_policy))
+		goto out;
+
+	return 0;
+out:
+	securityfs_remove(violations);
+	securityfs_remove(runtime_measurements_count);
+	securityfs_remove(ascii_runtime_measurements);
+	securityfs_remove(binary_runtime_measurements);
+	securityfs_remove(ima_dir);
+	securityfs_remove(ima_policy);
+	return -1;
+}

security/integrity/ima/ima_init.c

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer      <sailer@watson.ibm.com>
+ * Leendert van Doorn <leendert@watson.ibm.com>
+ * 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_init.c
+ *             initialization and cleanup functions
+ */
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include "ima.h"
+
+/* name for boot aggregate entry */
+static const char *boot_aggregate_name = "boot_aggregate";
+int ima_used_chip;
+
+/* Add the boot aggregate to the IMA measurement list and extend
+ * the PCR register.
+ *
+ * Calculate the boot aggregate, a SHA1 over tpm registers 0-7,
+ * assuming a TPM chip exists, and zeroes if the TPM chip does not
+ * exist.  Add the boot aggregate measurement to the measurement
+ * list and extend the PCR register.
+ *
+ * If a tpm chip does not exist, indicate the core root of trust is
+ * not hardware based by invalidating the aggregate PCR value.
+ * (The aggregate PCR value is invalidated by adding one value to
+ * the measurement list and extending the aggregate PCR value with
+ * a different value.) Violations add a zero entry to the measurement
+ * list and extend the aggregate PCR value with ff...ff's.
+ */
+static void __init ima_add_boot_aggregate(void)
+{
+	struct ima_template_entry *entry;
+	const char *op = "add_boot_aggregate";
+	const char *audit_cause = "ENOMEM";
+	int result = -ENOMEM;
+	int violation = 1;
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		goto err_out;
+
+	memset(&entry->template, 0, sizeof(entry->template));
+	strncpy(entry->template.file_name, boot_aggregate_name,
+		IMA_EVENT_NAME_LEN_MAX);
+	if (ima_used_chip) {
+		violation = 0;
+		result = ima_calc_boot_aggregate(entry->template.digest);
+		if (result < 0) {
+			audit_cause = "hashing_error";
+			kfree(entry);
+			goto err_out;
+		}
+	}
+	result = ima_store_template(entry, violation, NULL);
+	if (result < 0)
+		kfree(entry);
+	return;
+err_out:
+	integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
+			    audit_cause, result, 0);
+}
+
+int __init ima_init(void)
+{
+	u8 pcr_i[IMA_DIGEST_SIZE];
+	int rc;
+
+	ima_used_chip = 0;
+	rc = tpm_pcr_read(TPM_ANY_NUM, 0, pcr_i);
+	if (rc == 0)
+		ima_used_chip = 1;
+
+	if (!ima_used_chip)
+		pr_info("IMA: No TPM chip found, activating TPM-bypass!\n");
+
+	rc = ima_init_crypto();
+	if (rc)
+		return rc;
+	ima_add_boot_aggregate();	/* boot aggregate must be first entry */
+	ima_init_policy();
+
+	return ima_fs_init();
+}

security/integrity/ima/ima_main.c

@@ -0,0 +1,306 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * Serge Hallyn <serue@us.ibm.com>
+ * Kylene Hall <kylene@us.ibm.com>
+ * 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_main.c
+ *	implements the IMA hooks: ima_bprm_check, ima_file_mmap,
+ *	and ima_file_check.
+ */
+#include <linux/module.h>
+#include <linux/file.h>
+#include <linux/binfmts.h>
+#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_ENFORCE;
+#else
+int ima_appraise;
+#endif
+
+char *ima_hash = "sha1";
+static int __init hash_setup(char *str)
+{
+	if (strncmp(str, "md5", 3) == 0)
+		ima_hash = "md5";
+	return 1;
+}
+__setup("ima_hash=", hash_setup);
+
+/*
+ * ima_rdwr_violation_check
+ *
+ * Only invalidate the PCR for measured files:
+ * 	- Opening a file for write when already open for read,
+ *	  results in a time of measure, time of use (ToMToU) error.
+ *	- Opening a file for read when already open for write,
+ * 	  could result in a file measurement error.
+ *
+ */
+static void ima_rdwr_violation_check(struct file *file)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+	fmode_t mode = file->f_mode;
+	int must_measure;
+	bool send_tomtou = false, send_writers = false;
+	char *pathbuf = NULL;
+	const char *pathname;
+
+	if (!S_ISREG(inode->i_mode) || !ima_initialized)
+		return;
+
+	mutex_lock(&inode->i_mutex);	/* file metadata: permissions, xattr */
+
+	if (mode & FMODE_WRITE) {
+		if (atomic_read(&inode->i_readcount) && IS_IMA(inode))
+			send_tomtou = true;
+		goto out;
+	}
+
+	must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK);
+	if (!must_measure)
+		goto out;
+
+	if (atomic_read(&inode->i_writecount) > 0)
+		send_writers = true;
+out:
+	mutex_unlock(&inode->i_mutex);
+
+	if (!send_tomtou && !send_writers)
+		return;
+
+	pathname = ima_d_path(&file->f_path, &pathbuf);
+	if (!pathname || strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
+		pathname = dentry->d_name.name;
+
+	if (send_tomtou)
+		ima_add_violation(inode, pathname,
+				  "invalid_pcr", "ToMToU");
+	if (send_writers)
+		ima_add_violation(inode, pathname,
+				  "invalid_pcr", "open_writers");
+	kfree(pathbuf);
+}
+
+static void ima_check_last_writer(struct integrity_iint_cache *iint,
+				  struct inode *inode, struct file *file)
+{
+	fmode_t mode = file->f_mode;
+
+	if (!(mode & FMODE_WRITE))
+		return;
+
+	mutex_lock(&inode->i_mutex);
+	if (atomic_read(&inode->i_writecount) == 1 &&
+	    iint->version != inode->i_version) {
+		iint->flags &= ~IMA_DONE_MASK;
+		if (iint->flags & IMA_APPRAISE)
+			ima_update_xattr(iint, file);
+	}
+	mutex_unlock(&inode->i_mutex);
+}
+
+/**
+ * ima_file_free - called on __fput()
+ * @file: pointer to file structure being freed
+ *
+ * Flag files that changed, based on i_version
+ */
+void ima_file_free(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	struct integrity_iint_cache *iint;
+
+	if (!iint_initialized || !S_ISREG(inode->i_mode))
+		return;
+
+	iint = integrity_iint_find(inode);
+	if (!iint)
+		return;
+
+	ima_check_last_writer(iint, inode, file);
+}
+
+static int process_measurement(struct file *file, const char *filename,
+			       int mask, int function)
+{
+	struct inode *inode = file_inode(file);
+	struct integrity_iint_cache *iint;
+	char *pathbuf = NULL;
+	const char *pathname = NULL;
+	int rc = -ENOMEM, action, must_appraise, _func;
+
+	if (!ima_initialized || !S_ISREG(inode->i_mode))
+		return 0;
+
+	/* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
+	 * bitmask based on the appraise/audit/measurement policy.
+	 * Included is the appraise submask.
+	 */
+	action = ima_get_action(inode, mask, function);
+	if (!action)
+		return 0;
+
+	must_appraise = action & IMA_APPRAISE;
+
+	/*  Is the appraise rule hook specific?  */
+	_func = (action & IMA_FILE_APPRAISE) ? FILE_CHECK : function;
+
+	mutex_lock(&inode->i_mutex);
+
+	iint = integrity_inode_get(inode);
+	if (!iint)
+		goto out;
+
+	/* Determine if already appraised/measured based on bitmask
+	 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
+	 *  IMA_AUDIT, IMA_AUDITED)
+	 */
+	iint->flags |= action;
+	action &= IMA_DO_MASK;
+	action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
+
+	/* Nothing to do, just return existing appraised status */
+	if (!action) {
+		if (must_appraise)
+			rc = ima_get_cache_status(iint, _func);
+		goto out_digsig;
+	}
+
+	rc = ima_collect_measurement(iint, file);
+	if (rc != 0)
+		goto out_digsig;
+
+	pathname = !filename ? ima_d_path(&file->f_path, &pathbuf) : filename;
+	if (!pathname)
+		pathname = (const char *)file->f_dentry->d_name.name;
+
+	if (action & IMA_MEASURE)
+		ima_store_measurement(iint, file, pathname);
+	if (action & IMA_APPRAISE_SUBMASK)
+		rc = ima_appraise_measurement(_func, iint, file, pathname);
+	if (action & IMA_AUDIT)
+		ima_audit_measurement(iint, pathname);
+	kfree(pathbuf);
+out_digsig:
+	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
+		rc = -EACCES;
+out:
+	mutex_unlock(&inode->i_mutex);
+	if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
+		return -EACCES;
+	return 0;
+}
+
+/**
+ * ima_file_mmap - based on policy, collect/store measurement.
+ * @file: pointer to the file to be measured (May be NULL)
+ * @prot: contains the protection that will be applied by the kernel.
+ *
+ * Measure files being mmapped executable based on the ima_must_measure()
+ * policy decision.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_file_mmap(struct file *file, unsigned long prot)
+{
+	if (file && (prot & PROT_EXEC))
+		return process_measurement(file, NULL, MAY_EXEC, MMAP_CHECK);
+	return 0;
+}
+
+/**
+ * ima_bprm_check - based on policy, collect/store measurement.
+ * @bprm: contains the linux_binprm structure
+ *
+ * The OS protects against an executable file, already open for write,
+ * from being executed in deny_write_access() and an executable file,
+ * already open for execute, from being modified in get_write_access().
+ * So we can be certain that what we verify and measure here is actually
+ * what is being executed.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_bprm_check(struct linux_binprm *bprm)
+{
+	return process_measurement(bprm->file,
+				 (strcmp(bprm->filename, bprm->interp) == 0) ?
+				 bprm->filename : bprm->interp,
+				 MAY_EXEC, BPRM_CHECK);
+}
+
+/**
+ * ima_path_check - based on policy, collect/store measurement.
+ * @file: pointer to the file to be measured
+ * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE
+ *
+ * Measure files based on the ima_must_measure() policy decision.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_file_check(struct file *file, int mask)
+{
+	ima_rdwr_violation_check(file);
+	return process_measurement(file, NULL,
+				 mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
+				 FILE_CHECK);
+}
+EXPORT_SYMBOL_GPL(ima_file_check);
+
+/**
+ * ima_module_check - based on policy, collect/store/appraise measurement.
+ * @file: pointer to the file to be measured/appraised
+ *
+ * Measure/appraise kernel modules based on policy.
+ *
+ * On success return 0.  On integrity appraisal error, assuming the file
+ * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
+ */
+int ima_module_check(struct file *file)
+{
+	if (!file) {
+#ifndef CONFIG_MODULE_SIG_FORCE
+		if ((ima_appraise & IMA_APPRAISE_MODULES) &&
+		    (ima_appraise & IMA_APPRAISE_ENFORCE))
+			return -EACCES;	/* INTEGRITY_UNKNOWN */
+#endif
+		return 0;	/* We rely on module signature checking */
+	}
+	return process_measurement(file, NULL, MAY_EXEC, MODULE_CHECK);
+}
+
+static int __init init_ima(void)
+{
+	int error;
+
+	error = ima_init();
+	if (!error)
+		ima_initialized = 1;
+	return error;
+}
+
+late_initcall(init_ima);	/* Start IMA after the TPM is available */
+
+MODULE_DESCRIPTION("Integrity Measurement Architecture");
+MODULE_LICENSE("GPL");

security/integrity/ima/ima_policy.c

@@ -0,0 +1,711 @@
+/*
+ * Copyright (C) 2008 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.
+ *
+ * ima_policy.c
+ * 	- initialize default measure policy rules
+ *
+ */
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/security.h>
+#include <linux/magic.h>
+#include <linux/parser.h>
+#include <linux/slab.h>
+#include <linux/genhd.h>
+
+#include "ima.h"
+
+/* flags definitions */
+#define IMA_FUNC 	0x0001
+#define IMA_MASK 	0x0002
+#define IMA_FSMAGIC	0x0004
+#define IMA_UID		0x0008
+#define IMA_FOWNER	0x0010
+#define IMA_FSUUID	0x0020
+
+#define UNKNOWN		0
+#define MEASURE		0x0001	/* same as IMA_MEASURE */
+#define DONT_MEASURE	0x0002
+#define APPRAISE	0x0004	/* same as IMA_APPRAISE */
+#define DONT_APPRAISE	0x0008
+#define AUDIT		0x0040
+
+#define MAX_LSM_RULES 6
+enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
+	LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
+};
+
+struct ima_rule_entry {
+	struct list_head list;
+	int action;
+	unsigned int flags;
+	enum ima_hooks func;
+	int mask;
+	unsigned long fsmagic;
+	u8 fsuuid[16];
+	kuid_t uid;
+	kuid_t fowner;
+	struct {
+		void *rule;	/* LSM file metadata specific */
+		void *args_p;	/* audit value */
+		int type;	/* audit type */
+	} lsm[MAX_LSM_RULES];
+};
+
+/*
+ * Without LSM specific knowledge, the default policy can only be
+ * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
+ */
+
+/*
+ * The minimum rule set to allow for full TCB coverage.  Measures all files
+ * opened or mmap for exec and everything read by root.  Dangerous because
+ * normal users can easily run the machine out of memory simply building
+ * and running executables.
+ */
+static struct ima_rule_entry default_rules[] = {
+	{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = RAMFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = DEVPTS_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = BINFMTFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = MEASURE,.func = MMAP_CHECK,.mask = MAY_EXEC,
+	 .flags = IMA_FUNC | IMA_MASK},
+	{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
+	 .flags = IMA_FUNC | IMA_MASK},
+	{.action = MEASURE,.func = FILE_CHECK,.mask = MAY_READ,.uid = GLOBAL_ROOT_UID,
+	 .flags = IMA_FUNC | IMA_MASK | IMA_UID},
+	{.action = MEASURE,.func = MODULE_CHECK, .flags = IMA_FUNC},
+};
+
+static struct ima_rule_entry default_appraise_rules[] = {
+	{.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 = RAMFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_APPRAISE,.fsmagic = DEVPTS_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_APPRAISE,.fsmagic = BINFMTFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_APPRAISE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_APPRAISE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_APPRAISE,.fsmagic = CGROUP_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = APPRAISE,.fowner = GLOBAL_ROOT_UID,.flags = IMA_FOWNER},
+};
+
+static LIST_HEAD(ima_default_rules);
+static LIST_HEAD(ima_policy_rules);
+static struct list_head *ima_rules;
+
+static DEFINE_MUTEX(ima_rules_mutex);
+
+static bool ima_use_tcb __initdata;
+static int __init default_measure_policy_setup(char *str)
+{
+	ima_use_tcb = 1;
+	return 1;
+}
+__setup("ima_tcb", default_measure_policy_setup);
+
+static bool ima_use_appraise_tcb __initdata;
+static int __init default_appraise_policy_setup(char *str)
+{
+	ima_use_appraise_tcb = 1;
+	return 1;
+}
+__setup("ima_appraise_tcb", default_appraise_policy_setup);
+
+/* 
+ * Although the IMA policy does not change, the LSM policy can be
+ * reloaded, leaving the IMA LSM based rules referring to the old,
+ * stale LSM policy.
+ *
+ * Update the IMA LSM based rules to reflect the reloaded LSM policy. 
+ * We assume the rules still exist; and BUG_ON() if they don't.
+ */
+static void ima_lsm_update_rules(void)
+{
+	struct ima_rule_entry *entry, *tmp;
+	int result;
+	int i;
+
+	mutex_lock(&ima_rules_mutex);
+	list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
+		for (i = 0; i < MAX_LSM_RULES; i++) {
+			if (!entry->lsm[i].rule)
+				continue;
+			result = security_filter_rule_init(entry->lsm[i].type,
+							   Audit_equal,
+							   entry->lsm[i].args_p,
+							   &entry->lsm[i].rule);
+			BUG_ON(!entry->lsm[i].rule);
+		}
+	}
+	mutex_unlock(&ima_rules_mutex);
+}
+
+/**
+ * ima_match_rules - determine whether an inode matches the measure rule.
+ * @rule: a pointer to a rule
+ * @inode: a pointer to an inode
+ * @func: LIM hook identifier
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ *
+ * Returns true on rule match, false on failure.
+ */
+static bool ima_match_rules(struct ima_rule_entry *rule,
+			    struct inode *inode, enum ima_hooks func, int mask)
+{
+	struct task_struct *tsk = current;
+	const struct cred *cred = current_cred();
+	int i;
+
+	if ((rule->flags & IMA_FUNC) && rule->func != func)
+		return false;
+	if ((rule->flags & IMA_MASK) && rule->mask != mask)
+		return false;
+	if ((rule->flags & IMA_FSMAGIC)
+	    && rule->fsmagic != inode->i_sb->s_magic)
+		return false;
+	if ((rule->flags & IMA_FSUUID) &&
+	    memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+		return false;
+	if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
+		return false;
+	if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid))
+		return false;
+	for (i = 0; i < MAX_LSM_RULES; i++) {
+		int rc = 0;
+		u32 osid, sid;
+		int retried = 0;
+
+		if (!rule->lsm[i].rule)
+			continue;
+retry:
+		switch (i) {
+		case LSM_OBJ_USER:
+		case LSM_OBJ_ROLE:
+		case LSM_OBJ_TYPE:
+			security_inode_getsecid(inode, &osid);
+			rc = security_filter_rule_match(osid,
+							rule->lsm[i].type,
+							Audit_equal,
+							rule->lsm[i].rule,
+							NULL);
+			break;
+		case LSM_SUBJ_USER:
+		case LSM_SUBJ_ROLE:
+		case LSM_SUBJ_TYPE:
+			security_task_getsecid(tsk, &sid);
+			rc = security_filter_rule_match(sid,
+							rule->lsm[i].type,
+							Audit_equal,
+							rule->lsm[i].rule,
+							NULL);
+		default:
+			break;
+		}
+		if ((rc < 0) && (!retried)) {
+			retried = 1;
+			ima_lsm_update_rules();
+			goto retry;
+		} 
+		if (!rc)
+			return false;
+	}
+	return true;
+}
+
+/*
+ * In addition to knowing that we need to appraise the file in general,
+ * we need to differentiate between calling hooks, for hook specific rules.
+ */
+static int get_subaction(struct ima_rule_entry *rule, int func)
+{
+	if (!(rule->flags & IMA_FUNC))
+		return IMA_FILE_APPRAISE;
+
+	switch(func) {
+	case MMAP_CHECK:
+		return IMA_MMAP_APPRAISE;
+	case BPRM_CHECK:
+		return IMA_BPRM_APPRAISE;
+	case MODULE_CHECK:
+		return IMA_MODULE_APPRAISE;
+	case FILE_CHECK:
+	default:
+		return IMA_FILE_APPRAISE;
+	}
+}
+
+/**
+ * ima_match_policy - decision based on LSM and other conditions
+ * @inode: pointer to an inode for which the policy decision is being made
+ * @func: IMA hook identifier
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ *
+ * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
+ * conditions.
+ *
+ * (There is no need for locking when walking the policy list,
+ * as elements in the list are never deleted, nor does the list
+ * change.)
+ */
+int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
+		     int flags)
+{
+	struct ima_rule_entry *entry;
+	int action = 0, actmask = flags | (flags << 1);
+
+	list_for_each_entry(entry, ima_rules, list) {
+
+		if (!(entry->action & actmask))
+			continue;
+
+		if (!ima_match_rules(entry, inode, func, mask))
+			continue;
+
+		action |= entry->flags & IMA_ACTION_FLAGS;
+
+		action |= entry->action & IMA_DO_MASK;
+		if (entry->action & IMA_APPRAISE)
+			action |= get_subaction(entry, func);
+
+		if (entry->action & IMA_DO_MASK)
+			actmask &= ~(entry->action | entry->action << 1);
+		else
+			actmask &= ~(entry->action | entry->action >> 1);
+
+		if (!actmask)
+			break;
+	}
+
+	return action;
+}
+
+/**
+ * ima_init_policy - initialize the default measure rules.
+ *
+ * ima_rules points to either the ima_default_rules or the
+ * the new ima_policy_rules.
+ */
+void __init ima_init_policy(void)
+{
+	int i, measure_entries, appraise_entries;
+
+	/* if !ima_use_tcb set entries = 0 so we load NO default rules */
+	measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0;
+	appraise_entries = ima_use_appraise_tcb ?
+			 ARRAY_SIZE(default_appraise_rules) : 0;
+	
+	for (i = 0; i < measure_entries + appraise_entries; i++) {
+		if (i < measure_entries)
+			list_add_tail(&default_rules[i].list,
+				      &ima_default_rules);
+		else {
+			int j = i - measure_entries;
+
+			list_add_tail(&default_appraise_rules[j].list,
+				      &ima_default_rules);
+		}
+	}
+
+	ima_rules = &ima_default_rules;
+}
+
+/**
+ * ima_update_policy - update default_rules with new measure rules
+ *
+ * Called on file .release to update the default rules with a complete new
+ * policy.  Once updated, the policy is locked, no additional rules can be
+ * added to the policy.
+ */
+void ima_update_policy(void)
+{
+	const char *op = "policy_update";
+	const char *cause = "already exists";
+	int result = 1;
+	int audit_info = 0;
+
+	if (ima_rules == &ima_default_rules) {
+		ima_rules = &ima_policy_rules;
+		cause = "complete";
+		result = 0;
+	}
+	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
+			    NULL, op, cause, result, audit_info);
+}
+
+enum {
+	Opt_err = -1,
+	Opt_measure = 1, Opt_dont_measure,
+	Opt_appraise, Opt_dont_appraise,
+	Opt_audit,
+	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, Opt_fowner,
+	Opt_appraise_type, Opt_fsuuid
+};
+
+static match_table_t policy_tokens = {
+	{Opt_measure, "measure"},
+	{Opt_dont_measure, "dont_measure"},
+	{Opt_appraise, "appraise"},
+	{Opt_dont_appraise, "dont_appraise"},
+	{Opt_audit, "audit"},
+	{Opt_obj_user, "obj_user=%s"},
+	{Opt_obj_role, "obj_role=%s"},
+	{Opt_obj_type, "obj_type=%s"},
+	{Opt_subj_user, "subj_user=%s"},
+	{Opt_subj_role, "subj_role=%s"},
+	{Opt_subj_type, "subj_type=%s"},
+	{Opt_func, "func=%s"},
+	{Opt_mask, "mask=%s"},
+	{Opt_fsmagic, "fsmagic=%s"},
+	{Opt_fsuuid, "fsuuid=%s"},
+	{Opt_uid, "uid=%s"},
+	{Opt_fowner, "fowner=%s"},
+	{Opt_appraise_type, "appraise_type=%s"},
+	{Opt_err, NULL}
+};
+
+static int ima_lsm_rule_init(struct ima_rule_entry *entry,
+			     substring_t *args, int lsm_rule, int audit_type)
+{
+	int result;
+
+	if (entry->lsm[lsm_rule].rule)
+		return -EINVAL;
+
+	entry->lsm[lsm_rule].args_p = match_strdup(args);
+	if (!entry->lsm[lsm_rule].args_p)
+		return -ENOMEM;
+
+	entry->lsm[lsm_rule].type = audit_type;
+	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
+					   Audit_equal,
+					   entry->lsm[lsm_rule].args_p,
+					   &entry->lsm[lsm_rule].rule);
+	if (!entry->lsm[lsm_rule].rule) {
+		kfree(entry->lsm[lsm_rule].args_p);
+		return -EINVAL;
+	}
+
+	return result;
+}
+
+static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
+{
+	audit_log_format(ab, "%s=", key);
+	audit_log_untrustedstring(ab, value);
+	audit_log_format(ab, " ");
+}
+
+static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
+{
+	struct audit_buffer *ab;
+	char *p;
+	int result = 0;
+
+	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
+
+	entry->uid = INVALID_UID;
+	entry->fowner = INVALID_UID;
+	entry->action = UNKNOWN;
+	while ((p = strsep(&rule, " \t")) != NULL) {
+		substring_t args[MAX_OPT_ARGS];
+		int token;
+		unsigned long lnum;
+
+		if (result < 0)
+			break;
+		if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
+			continue;
+		token = match_token(p, policy_tokens, args);
+		switch (token) {
+		case Opt_measure:
+			ima_log_string(ab, "action", "measure");
+
+			if (entry->action != UNKNOWN)
+				result = -EINVAL;
+
+			entry->action = MEASURE;
+			break;
+		case Opt_dont_measure:
+			ima_log_string(ab, "action", "dont_measure");
+
+			if (entry->action != UNKNOWN)
+				result = -EINVAL;
+
+			entry->action = DONT_MEASURE;
+			break;
+		case Opt_appraise:
+			ima_log_string(ab, "action", "appraise");
+
+			if (entry->action != UNKNOWN)
+				result = -EINVAL;
+
+			entry->action = APPRAISE;
+			break;
+		case Opt_dont_appraise:
+			ima_log_string(ab, "action", "dont_appraise");
+
+			if (entry->action != UNKNOWN)
+				result = -EINVAL;
+
+			entry->action = DONT_APPRAISE;
+			break;
+		case Opt_audit:
+			ima_log_string(ab, "action", "audit");
+
+			if (entry->action != UNKNOWN)
+				result = -EINVAL;
+
+			entry->action = AUDIT;
+			break;
+		case Opt_func:
+			ima_log_string(ab, "func", args[0].from);
+
+			if (entry->func)
+				result = -EINVAL;
+
+			if (strcmp(args[0].from, "FILE_CHECK") == 0)
+				entry->func = FILE_CHECK;
+			/* PATH_CHECK is for backwards compat */
+			else if (strcmp(args[0].from, "PATH_CHECK") == 0)
+				entry->func = FILE_CHECK;
+			else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
+				entry->func = MODULE_CHECK;
+			else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
+				|| (strcmp(args[0].from, "MMAP_CHECK") == 0))
+				entry->func = MMAP_CHECK;
+			else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
+				entry->func = BPRM_CHECK;
+			else
+				result = -EINVAL;
+			if (!result)
+				entry->flags |= IMA_FUNC;
+			break;
+		case Opt_mask:
+			ima_log_string(ab, "mask", args[0].from);
+
+			if (entry->mask)
+				result = -EINVAL;
+
+			if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
+				entry->mask = MAY_EXEC;
+			else if (strcmp(args[0].from, "MAY_WRITE") == 0)
+				entry->mask = MAY_WRITE;
+			else if (strcmp(args[0].from, "MAY_READ") == 0)
+				entry->mask = MAY_READ;
+			else if (strcmp(args[0].from, "MAY_APPEND") == 0)
+				entry->mask = MAY_APPEND;
+			else
+				result = -EINVAL;
+			if (!result)
+				entry->flags |= IMA_MASK;
+			break;
+		case Opt_fsmagic:
+			ima_log_string(ab, "fsmagic", args[0].from);
+
+			if (entry->fsmagic) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = strict_strtoul(args[0].from, 16,
+						&entry->fsmagic);
+			if (!result)
+				entry->flags |= IMA_FSMAGIC;
+			break;
+		case Opt_fsuuid:
+			ima_log_string(ab, "fsuuid", args[0].from);
+
+			if (memchr_inv(entry->fsuuid, 0x00,
+				       sizeof(entry->fsuuid))) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = blk_part_pack_uuid(args[0].from,
+						    entry->fsuuid);
+			if (!result)
+				entry->flags |= IMA_FSUUID;
+			break;
+		case Opt_uid:
+			ima_log_string(ab, "uid", args[0].from);
+
+			if (uid_valid(entry->uid)) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = strict_strtoul(args[0].from, 10, &lnum);
+			if (!result) {
+				entry->uid = make_kuid(current_user_ns(), (uid_t)lnum);
+				if (!uid_valid(entry->uid) || (((uid_t)lnum) != lnum))
+					result = -EINVAL;
+				else
+					entry->flags |= IMA_UID;
+			}
+			break;
+		case Opt_fowner:
+			ima_log_string(ab, "fowner", args[0].from);
+
+			if (uid_valid(entry->fowner)) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = strict_strtoul(args[0].from, 10, &lnum);
+			if (!result) {
+				entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
+				if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
+					result = -EINVAL;
+				else
+					entry->flags |= IMA_FOWNER;
+			}
+			break;
+		case Opt_obj_user:
+			ima_log_string(ab, "obj_user", args[0].from);
+			result = ima_lsm_rule_init(entry, args,
+						   LSM_OBJ_USER,
+						   AUDIT_OBJ_USER);
+			break;
+		case Opt_obj_role:
+			ima_log_string(ab, "obj_role", args[0].from);
+			result = ima_lsm_rule_init(entry, args,
+						   LSM_OBJ_ROLE,
+						   AUDIT_OBJ_ROLE);
+			break;
+		case Opt_obj_type:
+			ima_log_string(ab, "obj_type", args[0].from);
+			result = ima_lsm_rule_init(entry, args,
+						   LSM_OBJ_TYPE,
+						   AUDIT_OBJ_TYPE);
+			break;
+		case Opt_subj_user:
+			ima_log_string(ab, "subj_user", args[0].from);
+			result = ima_lsm_rule_init(entry, args,
+						   LSM_SUBJ_USER,
+						   AUDIT_SUBJ_USER);
+			break;
+		case Opt_subj_role:
+			ima_log_string(ab, "subj_role", args[0].from);
+			result = ima_lsm_rule_init(entry, args,
+						   LSM_SUBJ_ROLE,
+						   AUDIT_SUBJ_ROLE);
+			break;
+		case Opt_subj_type:
+			ima_log_string(ab, "subj_type", args[0].from);
+			result = ima_lsm_rule_init(entry, args,
+						   LSM_SUBJ_TYPE,
+						   AUDIT_SUBJ_TYPE);
+			break;
+		case Opt_appraise_type:
+			if (entry->action != APPRAISE) {
+				result = -EINVAL;
+				break;
+			}
+
+			ima_log_string(ab, "appraise_type", args[0].from);
+			if ((strcmp(args[0].from, "imasig")) == 0)
+				entry->flags |= IMA_DIGSIG_REQUIRED;
+			else
+				result = -EINVAL;
+			break;
+		case Opt_err:
+			ima_log_string(ab, "UNKNOWN", p);
+			result = -EINVAL;
+			break;
+		}
+	}
+	if (!result && (entry->action == UNKNOWN))
+		result = -EINVAL;
+	else if (entry->func == MODULE_CHECK)
+		ima_appraise |= IMA_APPRAISE_MODULES;
+	audit_log_format(ab, "res=%d", !result);
+	audit_log_end(ab);
+	return result;
+}
+
+/**
+ * ima_parse_add_rule - add a rule to ima_policy_rules
+ * @rule - ima measurement policy rule
+ *
+ * Uses a mutex to protect the policy list from multiple concurrent writers.
+ * Returns the length of the rule parsed, an error code on failure
+ */
+ssize_t ima_parse_add_rule(char *rule)
+{
+	const char *op = "update_policy";
+	char *p;
+	struct ima_rule_entry *entry;
+	ssize_t result, len;
+	int audit_info = 0;
+
+	/* Prevent installed policy from changing */
+	if (ima_rules != &ima_default_rules) {
+		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
+				    NULL, op, "already exists",
+				    -EACCES, audit_info);
+		return -EACCES;
+	}
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry) {
+		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
+				    NULL, op, "-ENOMEM", -ENOMEM, audit_info);
+		return -ENOMEM;
+	}
+
+	INIT_LIST_HEAD(&entry->list);
+
+	p = strsep(&rule, "\n");
+	len = strlen(p) + 1;
+
+	if (*p == '#') {
+		kfree(entry);
+		return len;
+	}
+
+	result = ima_parse_rule(p, entry);
+	if (result) {
+		kfree(entry);
+		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
+				    NULL, op, "invalid policy", result,
+				    audit_info);
+		return result;
+	}
+
+	mutex_lock(&ima_rules_mutex);
+	list_add_tail(&entry->list, &ima_policy_rules);
+	mutex_unlock(&ima_rules_mutex);
+
+	return len;
+}
+
+/* ima_delete_rules called to cleanup invalid policy */
+void ima_delete_rules(void)
+{
+	struct ima_rule_entry *entry, *tmp;
+	int i;
+
+	mutex_lock(&ima_rules_mutex);
+	list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
+		for (i = 0; i < MAX_LSM_RULES; i++)
+			kfree(entry->lsm[i].args_p);
+
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	mutex_unlock(&ima_rules_mutex);
+}

security/integrity/ima/ima_queue.c

@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Serge Hallyn <serue@us.ibm.com>
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * 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_queue.c
+ *       Implements queues that store template measurements and
+ *       maintains aggregate over the stored measurements
+ *       in the pre-configured TPM PCR (if available).
+ *       The measurement list is append-only. No entry is
+ *       ever removed or changed during the boot-cycle.
+ */
+#include <linux/module.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include "ima.h"
+
+#define AUDIT_CAUSE_LEN_MAX 32
+
+LIST_HEAD(ima_measurements);	/* list of all measurements */
+
+/* key: inode (before secure-hashing a file) */
+struct ima_h_table ima_htable = {
+	.len = ATOMIC_LONG_INIT(0),
+	.violations = ATOMIC_LONG_INIT(0),
+	.queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
+};
+
+/* mutex protects atomicity of extending measurement list
+ * and extending the TPM PCR aggregate. Since tpm_extend can take
+ * long (and the tpm driver uses a mutex), we can't use the spinlock.
+ */
+static DEFINE_MUTEX(ima_extend_list_mutex);
+
+/* lookup up the digest value in the hash table, and return the entry */
+static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
+{
+	struct ima_queue_entry *qe, *ret = NULL;
+	unsigned int key;
+	int rc;
+
+	key = ima_hash_key(digest_value);
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
+		rc = memcmp(qe->entry->digest, digest_value, IMA_DIGEST_SIZE);
+		if (rc == 0) {
+			ret = qe;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return ret;
+}
+
+/* ima_add_template_entry helper function:
+ * - Add template entry to measurement list and hash table.
+ *
+ * (Called with ima_extend_list_mutex held.)
+ */
+static int ima_add_digest_entry(struct ima_template_entry *entry)
+{
+	struct ima_queue_entry *qe;
+	unsigned int key;
+
+	qe = kmalloc(sizeof(*qe), GFP_KERNEL);
+	if (qe == NULL) {
+		pr_err("IMA: OUT OF MEMORY ERROR creating queue entry.\n");
+		return -ENOMEM;
+	}
+	qe->entry = entry;
+
+	INIT_LIST_HEAD(&qe->later);
+	list_add_tail_rcu(&qe->later, &ima_measurements);
+
+	atomic_long_inc(&ima_htable.len);
+	key = ima_hash_key(entry->digest);
+	hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
+	return 0;
+}
+
+static int ima_pcr_extend(const u8 *hash)
+{
+	int result = 0;
+
+	if (!ima_used_chip)
+		return result;
+
+	result = tpm_pcr_extend(TPM_ANY_NUM, CONFIG_IMA_MEASURE_PCR_IDX, hash);
+	if (result != 0)
+		pr_err("IMA: Error Communicating to TPM chip, result: %d\n",
+		       result);
+	return result;
+}
+
+/* Add template entry to the measurement list and hash table,
+ * and extend the pcr.
+ */
+int ima_add_template_entry(struct ima_template_entry *entry, int violation,
+			   const char *op, struct inode *inode)
+{
+	u8 digest[IMA_DIGEST_SIZE];
+	const char *audit_cause = "hash_added";
+	char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
+	int audit_info = 1;
+	int result = 0, tpmresult = 0;
+
+	mutex_lock(&ima_extend_list_mutex);
+	if (!violation) {
+		memcpy(digest, entry->digest, sizeof digest);
+		if (ima_lookup_digest_entry(digest)) {
+			audit_cause = "hash_exists";
+			result = -EEXIST;
+			goto out;
+		}
+	}
+
+	result = ima_add_digest_entry(entry);
+	if (result < 0) {
+		audit_cause = "ENOMEM";
+		audit_info = 0;
+		goto out;
+	}
+
+	if (violation)		/* invalidate pcr */
+		memset(digest, 0xff, sizeof digest);
+
+	tpmresult = ima_pcr_extend(digest);
+	if (tpmresult != 0) {
+		snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)",
+			 tpmresult);
+		audit_cause = tpm_audit_cause;
+		audit_info = 0;
+	}
+out:
+	mutex_unlock(&ima_extend_list_mutex);
+	integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
+			    entry->template.file_name,
+			    op, audit_cause, result, audit_info);
+	return result;
+}

security/integrity/integrity.h

@@ -0,0 +1,117 @@
+/*
+ * 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.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/integrity.h>
+#include <crypto/sha.h>
+#include <linux/key.h>
+
+/* iint action cache flags */
+#define IMA_MEASURE		0x00000001
+#define IMA_MEASURED		0x00000002
+#define IMA_APPRAISE		0x00000004
+#define IMA_APPRAISED		0x00000008
+/*#define IMA_COLLECT		0x00000010  do not use this flag */
+#define IMA_COLLECTED		0x00000020
+#define IMA_AUDIT		0x00000040
+#define IMA_AUDITED		0x00000080
+
+/* iint cache flags */
+#define IMA_ACTION_FLAGS	0xff000000
+#define IMA_DIGSIG		0x01000000
+#define IMA_DIGSIG_REQUIRED	0x02000000
+
+#define IMA_DO_MASK		(IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
+				 IMA_APPRAISE_SUBMASK)
+#define IMA_DONE_MASK		(IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
+				 IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
+
+/* iint subaction appraise cache flags */
+#define IMA_FILE_APPRAISE	0x00000100
+#define IMA_FILE_APPRAISED	0x00000200
+#define IMA_MMAP_APPRAISE	0x00000400
+#define IMA_MMAP_APPRAISED	0x00000800
+#define IMA_BPRM_APPRAISE	0x00001000
+#define IMA_BPRM_APPRAISED	0x00002000
+#define IMA_MODULE_APPRAISE	0x00004000
+#define IMA_MODULE_APPRAISED	0x00008000
+#define IMA_APPRAISE_SUBMASK	(IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
+				 IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE)
+#define IMA_APPRAISED_SUBMASK	(IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
+				 IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED)
+
+enum evm_ima_xattr_type {
+	IMA_XATTR_DIGEST = 0x01,
+	EVM_XATTR_HMAC,
+	EVM_IMA_XATTR_DIGSIG,
+};
+
+struct evm_ima_xattr_data {
+	u8 type;
+	u8 digest[SHA1_DIGEST_SIZE];
+}  __attribute__((packed));
+
+/* integrity data associated with an inode */
+struct integrity_iint_cache {
+	struct rb_node rb_node; /* rooted in integrity_iint_tree */
+	struct inode *inode;	/* back pointer to inode in question */
+	u64 version;		/* track inode changes */
+	unsigned long flags;
+	struct evm_ima_xattr_data ima_xattr;
+	enum integrity_status ima_file_status:4;
+	enum integrity_status ima_mmap_status:4;
+	enum integrity_status ima_bprm_status:4;
+	enum integrity_status ima_module_status:4;
+	enum integrity_status evm_status:4;
+};
+
+/* rbtree 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(struct inode *inode);
+
+#define INTEGRITY_KEYRING_EVM		0
+#define INTEGRITY_KEYRING_MODULE	1
+#define INTEGRITY_KEYRING_IMA		2
+#define INTEGRITY_KEYRING_MAX		3
+
+#ifdef CONFIG_INTEGRITY_SIGNATURE
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+					const char *digest, int digestlen);
+
+#else
+
+static inline int integrity_digsig_verify(const unsigned int id,
+					  const char *sig, int siglen,
+					  const char *digest, int digestlen)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_INTEGRITY_SIGNATURE */
+
+#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
+int asymmetric_verify(struct key *keyring, const char *sig,
+		      int siglen, const char *data, int datalen);
+#else
+static inline int asymmetric_verify(struct key *keyring, const char *sig,
+				    int siglen, const char *data, int datalen)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+/* set during initialization */
+extern int iint_initialized;