M7350v1_en_gpl

kernel/security/integrity/ima/Kconfig

@@ -0,0 +1,56 @@
+# 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
+	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
+	depends on IMA
+	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.

kernel/security/integrity/ima/Makefile

@@ -0,0 +1,9 @@
+#
+# Makefile for building Trusted Computing Group's(TCG) runtime Integrity
+# Measurement Architecture(IMA).
+#
+
+obj-$(CONFIG_IMA) += ima.o
+
+ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
+	 ima_policy.o ima_audit.o

kernel/security/integrity/ima/ima.h

@@ -0,0 +1,146 @@
+/*
+ * 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;
+
+/* 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 */
+
+/* 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);
+
+/* 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_hash(struct file *file, char *digest);
+int ima_calc_template_hash(int template_len, void *template, 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);
+
+/*
+ * 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_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);
+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);
+
+/* 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, FILE_MMAP, BPRM_CHECK };
+
+int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
+void ima_init_policy(void);
+void ima_update_policy(void);
+ssize_t ima_parse_add_rule(char *);
+void ima_delete_rules(void);
+
+/* 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

kernel/security/integrity/ima/ima_api.c

@@ -0,0 +1,185 @@
+/*
+ * 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_measure, collect_measurement, store_measurement,
+ *	and store_template.
+ */
+#include <linux/module.h>
+#include <linux/slab.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_template_hash(entry->template_len,
+						&entry->template,
+						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_must_measure - measure decision based on policy.
+ * @inode: pointer to inode to measure
+ * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE)
+ * @function: calling function (FILE_CHECK, BPRM_CHECK, FILE_MMAP)
+ *
+ * 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 | FILE_MMAP
+ * 	mask: contains the permission mask
+ *	fsmagic: hex value
+ *
+ * Return 0 to measure. For matching a DONT_MEASURE policy, no policy,
+ * or other error, return an error code.
+*/
+int ima_must_measure(struct inode *inode, int mask, int function)
+{
+	int must_measure;
+
+	must_measure = ima_match_policy(inode, function, mask);
+	return must_measure ? 0 : -EACCES;
+}
+
+/*
+ * 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)
+{
+	int result = -EEXIST;
+
+	if (!(iint->flags & IMA_MEASURED)) {
+		u64 i_version = file->f_dentry->d_inode->i_version;
+
+		memset(iint->digest, 0, IMA_DIGEST_SIZE);
+		result = ima_calc_hash(file, iint->digest);
+		if (!result)
+			iint->version = i_version;
+	}
+	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->f_dentry->d_inode;
+	struct ima_template_entry *entry;
+	int violation = 0;
+
+	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->digest, IMA_DIGEST_SIZE);
+	strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);
+
+	result = ima_store_template(entry, violation, inode);
+	if (!result || result == -EEXIST)
+		iint->flags |= IMA_MEASURED;
+	if (result < 0)
+		kfree(entry);
+}

kernel/security/integrity/ima/ima_audit.c

@@ -0,0 +1,66 @@
+/*
+ * 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;
+
+#ifdef CONFIG_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);
+#endif
+
+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, current_cred()->uid,
+			 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);
+}

kernel/security/integrity/ima/ima_crypto.c

@@ -0,0 +1,143 @@
+/*
+ * 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 "ima.h"
+
+static int init_desc(struct hash_desc *desc)
+{
+	int rc;
+
+	desc->tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(desc->tfm)) {
+		pr_info("IMA: failed to load %s transform: %ld\n",
+			ima_hash, PTR_ERR(desc->tfm));
+		rc = PTR_ERR(desc->tfm);
+		return rc;
+	}
+	desc->flags = 0;
+	rc = crypto_hash_init(desc);
+	if (rc)
+		crypto_free_hash(desc->tfm);
+	return rc;
+}
+
+/*
+ * Calculate the MD5/SHA1 file digest
+ */
+int ima_calc_hash(struct file *file, char *digest)
+{
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	loff_t i_size, offset = 0;
+	char *rbuf;
+	int rc;
+
+	rc = init_desc(&desc);
+	if (rc != 0)
+		return rc;
+
+	rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!rbuf) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	i_size = i_size_read(file->f_dentry->d_inode);
+	while (offset < i_size) {
+		int rbuf_len;
+
+		rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
+		if (rbuf_len < 0) {
+			rc = rbuf_len;
+			break;
+		}
+		if (rbuf_len == 0)
+			break;
+		offset += rbuf_len;
+		sg_init_one(sg, rbuf, rbuf_len);
+
+		rc = crypto_hash_update(&desc, sg, rbuf_len);
+		if (rc)
+			break;
+	}
+	kfree(rbuf);
+	if (!rc)
+		rc = crypto_hash_final(&desc, digest);
+out:
+	crypto_free_hash(desc.tfm);
+	return rc;
+}
+
+/*
+ * Calculate the hash of a given template
+ */
+int ima_calc_template_hash(int template_len, void *template, char *digest)
+{
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	int rc;
+
+	rc = init_desc(&desc);
+	if (rc != 0)
+		return rc;
+
+	sg_init_one(sg, template, template_len);
+	rc = crypto_hash_update(&desc, sg, template_len);
+	if (!rc)
+		rc = crypto_hash_final(&desc, digest);
+	crypto_free_hash(desc.tfm);
+	return rc;
+}
+
+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)
+{
+	struct hash_desc desc;
+	struct scatterlist sg;
+	u8 pcr_i[IMA_DIGEST_SIZE];
+	int rc, i;
+
+	rc = init_desc(&desc);
+	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 */
+		sg_init_one(&sg, pcr_i, IMA_DIGEST_SIZE);
+		rc = crypto_hash_update(&desc, &sg, IMA_DIGEST_SIZE);
+	}
+	if (!rc)
+		crypto_hash_final(&desc, digest);
+	crypto_free_hash(desc.tfm);
+	return rc;
+}

kernel/security/integrity/ima/ima_fs.c

@@ -0,0 +1,386 @@
+/*
+ * 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(runtime_measurements_count);
+	securityfs_remove(ascii_runtime_measurements);
+	securityfs_remove(binary_runtime_measurements);
+	securityfs_remove(ima_dir);
+	securityfs_remove(ima_policy);
+	return -1;
+}
+
+void __exit ima_fs_cleanup(void)
+{
+	securityfs_remove(violations);
+	securityfs_remove(runtime_measurements_count);
+	securityfs_remove(ascii_runtime_measurements);
+	securityfs_remove(binary_runtime_measurements);
+	securityfs_remove(ima_dir);
+	securityfs_remove(ima_policy);
+}

kernel/security/integrity/ima/ima_init.c

@@ -0,0 +1,97 @@
+/*
+ * 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");
+
+	ima_add_boot_aggregate();	/* boot aggregate must be first entry */
+	ima_init_policy();
+
+	return ima_fs_init();
+}
+
+void __exit ima_cleanup(void)
+{
+	ima_fs_cleanup();
+}

kernel/security/integrity/ima/ima_main.c

@@ -0,0 +1,241 @@
+/*
+ * 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/ima.h>
+
+#include "ima.h"
+
+int ima_initialized;
+
+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 rc;
+	bool send_tomtou = false, send_writers = false;
+
+	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;
+	}
+
+	rc = ima_must_measure(inode, MAY_READ, FILE_CHECK);
+	if (rc < 0)
+		goto out;
+
+	if (atomic_read(&inode->i_writecount) > 0)
+		send_writers = true;
+out:
+	mutex_unlock(&inode->i_mutex);
+
+	if (send_tomtou)
+		ima_add_violation(inode, dentry->d_name.name, "invalid_pcr",
+				  "ToMToU");
+	if (send_writers)
+		ima_add_violation(inode, dentry->d_name.name, "invalid_pcr",
+				  "open_writers");
+}
+
+static void ima_check_last_writer(struct integrity_iint_cache *iint,
+				  struct inode *inode,
+				  struct file *file)
+{
+	fmode_t mode = file->f_mode;
+
+	mutex_lock(&iint->mutex);
+	if (mode & FMODE_WRITE &&
+	    atomic_read(&inode->i_writecount) == 1 &&
+	    iint->version != inode->i_version)
+		iint->flags &= ~IMA_MEASURED;
+	mutex_unlock(&iint->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->f_dentry->d_inode;
+	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 unsigned char *filename,
+			       int mask, int function)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct integrity_iint_cache *iint;
+	int rc = 0;
+
+	if (!ima_initialized || !S_ISREG(inode->i_mode))
+		return 0;
+
+	rc = ima_must_measure(inode, mask, function);
+	if (rc != 0)
+		return rc;
+retry:
+	iint = integrity_iint_find(inode);
+	if (!iint) {
+		rc = integrity_inode_alloc(inode);
+		if (!rc || rc == -EEXIST)
+			goto retry;
+		return rc;
+	}
+
+	mutex_lock(&iint->mutex);
+
+	rc = iint->flags & IMA_MEASURED ? 1 : 0;
+	if (rc != 0)
+		goto out;
+
+	rc = ima_collect_measurement(iint, file);
+	if (!rc)
+		ima_store_measurement(iint, file, filename);
+out:
+	mutex_unlock(&iint->mutex);
+	return rc;
+}
+
+/**
+ * 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.
+ *
+ * Return 0 on success, an error code on failure.
+ * (Based on the results of appraise_measurement().)
+ */
+int ima_file_mmap(struct file *file, unsigned long prot)
+{
+	int rc;
+
+	if (!file)
+		return 0;
+	if (prot & PROT_EXEC)
+		rc = process_measurement(file, file->f_dentry->d_name.name,
+					 MAY_EXEC, FILE_MMAP);
+	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.
+ *
+ * Return 0 on success, an error code on failure.
+ * (Based on the results of appraise_measurement().)
+ */
+int ima_bprm_check(struct linux_binprm *bprm)
+{
+	int rc;
+
+	rc = process_measurement(bprm->file, bprm->filename,
+				 MAY_EXEC, BPRM_CHECK);
+	return 0;
+}
+
+/**
+ * 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.
+ *
+ * Always return 0 and audit dentry_open failures.
+ * (Return code will be based upon measurement appraisal.)
+ */
+int ima_file_check(struct file *file, int mask)
+{
+	int rc;
+
+	ima_rdwr_violation_check(file);
+	rc = process_measurement(file, file->f_dentry->d_name.name,
+				 mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
+				 FILE_CHECK);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ima_file_check);
+
+static int __init init_ima(void)
+{
+	int error;
+
+	error = ima_init();
+	ima_initialized = 1;
+	return error;
+}
+
+static void __exit cleanup_ima(void)
+{
+	ima_cleanup();
+}
+
+late_initcall(init_ima);	/* Start IMA after the TPM is available */
+
+MODULE_DESCRIPTION("Integrity Measurement Architecture");
+MODULE_LICENSE("GPL");

kernel/security/integrity/ima/ima_policy.c

@@ -0,0 +1,493 @@
+/*
+ * 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 "ima.h"
+
+/* flags definitions */
+#define IMA_FUNC 	0x0001
+#define IMA_MASK 	0x0002
+#define IMA_FSMAGIC	0x0004
+#define IMA_UID		0x0008
+
+enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
+
+#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_measure_rule_entry {
+	struct list_head list;
+	enum ima_action action;
+	unsigned int flags;
+	enum ima_hooks func;
+	int mask;
+	unsigned long fsmagic;
+	uid_t uid;
+	struct {
+		void *rule;	/* LSM file metadata specific */
+		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, and .uid
+ */
+
+/*
+ * 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_measure_rule_entry default_rules[] = {
+	{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+	{.action = DONT_MEASURE,.fsmagic = RAMFS_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 = FILE_MMAP,.mask = MAY_EXEC,
+	 .flags = IMA_FUNC | IMA_MASK},
+	{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
+	 .flags = IMA_FUNC | IMA_MASK},
+	{.action = MEASURE,.func = FILE_CHECK,.mask = MAY_READ,.uid = 0,
+	 .flags = IMA_FUNC | IMA_MASK | IMA_UID},
+};
+
+static LIST_HEAD(measure_default_rules);
+static LIST_HEAD(measure_policy_rules);
+static struct list_head *ima_measure;
+
+static DEFINE_MUTEX(ima_measure_mutex);
+
+static bool ima_use_tcb __initdata;
+static int __init default_policy_setup(char *str)
+{
+	ima_use_tcb = 1;
+	return 1;
+}
+__setup("ima_tcb", default_policy_setup);
+
+/**
+ * ima_match_rules - determine whether an inode matches the measure rule.
+ * @rule: a pointer to a rule
+ * @inode: a pointer to an inode
+ * @func: LIM hook identifier
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ *
+ * Returns true on rule match, false on failure.
+ */
+static bool ima_match_rules(struct ima_measure_rule_entry *rule,
+			    struct inode *inode, enum 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_UID) && rule->uid != cred->uid)
+		return false;
+	for (i = 0; i < MAX_LSM_RULES; i++) {
+		int rc = 0;
+		u32 osid, sid;
+
+		if (!rule->lsm[i].rule)
+			continue;
+
+		switch (i) {
+		case LSM_OBJ_USER:
+		case LSM_OBJ_ROLE:
+		case LSM_OBJ_TYPE:
+			security_inode_getsecid(inode, &osid);
+			rc = security_filter_rule_match(osid,
+							rule->lsm[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)
+			return false;
+	}
+	return true;
+}
+
+/**
+ * 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)
+{
+	struct ima_measure_rule_entry *entry;
+
+	list_for_each_entry(entry, ima_measure, list) {
+		bool rc;
+
+		rc = ima_match_rules(entry, inode, func, mask);
+		if (rc)
+			return entry->action;
+	}
+	return 0;
+}
+
+/**
+ * ima_init_policy - initialize the default measure rules.
+ *
+ * ima_measure points to either the measure_default_rules or the
+ * the new measure_policy_rules.
+ */
+void __init ima_init_policy(void)
+{
+	int i, entries;
+
+	/* if !ima_use_tcb set entries = 0 so we load NO default rules */
+	if (ima_use_tcb)
+		entries = ARRAY_SIZE(default_rules);
+	else
+		entries = 0;
+
+	for (i = 0; i < entries; i++)
+		list_add_tail(&default_rules[i].list, &measure_default_rules);
+	ima_measure = &measure_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_measure == &measure_default_rules) {
+		ima_measure = &measure_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_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
+};
+
+static match_table_t policy_tokens = {
+	{Opt_measure, "measure"},
+	{Opt_dont_measure, "dont_measure"},
+	{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_uid, "uid=%s"},
+	{Opt_err, NULL}
+};
+
+static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
+			     char *args, int lsm_rule, int audit_type)
+{
+	int result;
+
+	if (entry->lsm[lsm_rule].rule)
+		return -EINVAL;
+
+	entry->lsm[lsm_rule].type = audit_type;
+	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
+					   Audit_equal, args,
+					   &entry->lsm[lsm_rule].rule);
+	if (!entry->lsm[lsm_rule].rule)
+		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_measure_rule_entry *entry)
+{
+	struct audit_buffer *ab;
+	char *p;
+	int result = 0;
+
+	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
+
+	entry->uid = -1;
+	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_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, "FILE_MMAP") == 0)
+				entry->func = FILE_MMAP;
+			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_uid:
+			ima_log_string(ab, "uid", args[0].from);
+
+			if (entry->uid != -1) {
+				result = -EINVAL;
+				break;
+			}
+
+			result = strict_strtoul(args[0].from, 10, &lnum);
+			if (!result) {
+				entry->uid = (uid_t) lnum;
+				if (entry->uid != lnum)
+					result = -EINVAL;
+				else
+					entry->flags |= IMA_UID;
+			}
+			break;
+		case Opt_obj_user:
+			ima_log_string(ab, "obj_user", args[0].from);
+			result = ima_lsm_rule_init(entry, args[0].from,
+						   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[0].from,
+						   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[0].from,
+						   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[0].from,
+						   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[0].from,
+						   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[0].from,
+						   LSM_SUBJ_TYPE,
+						   AUDIT_SUBJ_TYPE);
+			break;
+		case Opt_err:
+			ima_log_string(ab, "UNKNOWN", p);
+			result = -EINVAL;
+			break;
+		}
+	}
+	if (!result && (entry->action == UNKNOWN))
+		result = -EINVAL;
+
+	audit_log_format(ab, "res=%d", !result);
+	audit_log_end(ab);
+	return result;
+}
+
+/**
+ * ima_parse_add_rule - add a rule to measure_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_measure_rule_entry *entry;
+	ssize_t result, len;
+	int audit_info = 0;
+
+	/* Prevent installed policy from changing */
+	if (ima_measure != &measure_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_measure_mutex);
+	list_add_tail(&entry->list, &measure_policy_rules);
+	mutex_unlock(&ima_measure_mutex);
+
+	return len;
+}
+
+/* ima_delete_rules called to cleanup invalid policy */
+void ima_delete_rules(void)
+{
+	struct ima_measure_rule_entry *entry, *tmp;
+
+	mutex_lock(&ima_measure_mutex);
+	list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	mutex_unlock(&ima_measure_mutex);
+}

kernel/security/integrity/ima/ima_queue.c

@@ -0,0 +1,149 @@
+/*
+ * 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;
+	struct hlist_node *pos;
+	int rc;
+
+	key = ima_hash_key(digest_value);
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(qe, pos, &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;
+}