1 files changed, 254 insertions, 0 deletions
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
new file mode 100644
index 000000000..dbb6d141c
--- /dev/null
+++ b/security/integrity/iint.c
@@ -0,0 +1,254 @@
+/*
+ * 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 <linux/file.h>
+#include <linux/uaccess.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;
+
+/*
+ * __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)
+{
+	kfree(iint->ima_hash);
+	iint->ima_hash = NULL;
+	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);
+	return 0;
+}
+security_initcall(integrity_iintcache_init);
+
+
+/*
+ * integrity_kernel_read - read data from the file
+ *
+ * This is a function for reading file content instead of kernel_read().
+ * It does not perform locking checks to ensure it cannot be blocked.
+ * It does not perform security checks because it is irrelevant for IMA.
+ *
+ */
+int integrity_kernel_read(struct file *file, loff_t offset,
+			  char *addr, unsigned long count)
+{
+	mm_segment_t old_fs;
+	char __user *buf = (char __user *)addr;
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	ret = __vfs_read(file, buf, count, &offset);
+	set_fs(old_fs);
+
+	return ret;
+}
+
+/*
+ * integrity_read_file - read entire file content into the buffer
+ *
+ * This is function opens a file, allocates the buffer of required
+ * size, read entire file content to the buffer and closes the file
+ *
+ * It is used only by init code.
+ *
+ */
+int __init integrity_read_file(const char *path, char **data)
+{
+	struct file *file;
+	loff_t size;
+	char *buf;
+	int rc = -EINVAL;
+
+	file = filp_open(path, O_RDONLY, 0);
+	if (IS_ERR(file)) {
+		rc = PTR_ERR(file);
+		pr_err("Unable to open file: %s (%d)", path, rc);
+		return rc;
+	}
+
+	size = i_size_read(file_inode(file));
+	if (size <= 0)
+		goto out;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	rc = integrity_kernel_read(file, 0, buf, size);
+	if (rc < 0)
+		kfree(buf);
+	else if (rc != size)
+		rc = -EIO;
+	else
+		*data = buf;
+out:
+	fput(file);
+	return rc;
+}
+
+/*
+ * integrity_load_keys - load integrity keys hook
+ *
+ * Hooks is called from init/main.c:kernel_init_freeable()
+ * when rootfs is ready
+ */
+void __init integrity_load_keys(void)
+{
+	ima_load_x509();
+}