integrity: IMA hooks

This patch replaces the generic integrity hooks, for which IMA registered
itself, with IMA integrity hooks in the appropriate places directly
in the fs directory.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

Documentation/kernel-parameters.txt

@@ -44,6 +44,7 @@ parameter is applicable:
 	FB	The frame buffer device is enabled.
 	HW	Appropriate hardware is enabled.
 	IA-64	IA-64 architecture is enabled.
+	IMA     Integrity measurement architecture is enabled.
 	IOSCHED	More than one I/O scheduler is enabled.
 	IP_PNP	IP DHCP, BOOTP, or RARP is enabled.
 	ISAPNP	ISA PnP code is enabled.

fs/exec.c

@@ -45,6 +45,7 @@
 #include <linux/proc_fs.h>
 #include <linux/mount.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/syscalls.h>
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
@@ -128,6 +129,9 @@ asmlinkage long sys_uselib(const char __user * library)
 		goto exit;
 
 	error = vfs_permission(&nd, MAY_READ | MAY_EXEC | MAY_OPEN);
+	if (error)
+		goto exit;
+	error = ima_path_check(&nd.path, MAY_READ | MAY_EXEC | MAY_OPEN);
 	if (error)
 		goto exit;
 
@@ -681,6 +685,9 @@ struct file *open_exec(const char *name)
 		goto out_path_put;
 
 	err = vfs_permission(&nd, MAY_EXEC | MAY_OPEN);
+	if (err)
+		goto out_path_put;
+	err = ima_path_check(&nd.path, MAY_EXEC | MAY_OPEN);
 	if (err)
 		goto out_path_put;
 
@@ -1207,6 +1214,9 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
 	}
 #endif
 	retval = security_bprm_check(bprm);
+	if (retval)
+		return retval;
+	retval = ima_bprm_check(bprm);
 	if (retval)
 		return retval;
 

fs/file_table.c

@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/eventpoll.h>
 #include <linux/rcupdate.h>
 #include <linux/mount.h>
@@ -276,6 +277,7 @@ void __fput(struct file *file)
 	if (file->f_op && file->f_op->release)
 		file->f_op->release(inode, file);
 	security_file_free(file);
+	ima_file_free(file);
 	if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL))
 		cdev_put(inode->i_cdev);
 	fops_put(file->f_op);

fs/inode.c

@@ -17,6 +17,7 @@
 #include <linux/hash.h>
 #include <linux/swap.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/pagemap.h>
 #include <linux/cdev.h>
 #include <linux/bootmem.h>
@@ -144,13 +145,13 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode)
 	inode->i_cdev = NULL;
 	inode->i_rdev = 0;
 	inode->dirtied_when = 0;
-	if (security_inode_alloc(inode)) {
-		if (inode->i_sb->s_op->destroy_inode)
-			inode->i_sb->s_op->destroy_inode(inode);
-		else
-			kmem_cache_free(inode_cachep, (inode));
-		return NULL;
-	}
+
+	if (security_inode_alloc(inode))
+		goto out_free_inode;
+
+	/* allocate and initialize an i_integrity */
+	if (ima_inode_alloc(inode))
+		goto out_free_security;
 
 	spin_lock_init(&inode->i_lock);
 	lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
@@ -186,6 +187,15 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode)
 	inode->i_mapping = mapping;
 
 	return inode;
+
+out_free_security:
+	security_inode_free(inode);
+out_free_inode:
+	if (inode->i_sb->s_op->destroy_inode)
+		inode->i_sb->s_op->destroy_inode(inode);
+	else
+		kmem_cache_free(inode_cachep, (inode));
+	return NULL;
 }
 EXPORT_SYMBOL(inode_init_always);
 

fs/namei.c

@@ -24,6 +24,7 @@
 #include <linux/fsnotify.h>
 #include <linux/personality.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/syscalls.h>
 #include <linux/mount.h>
 #include <linux/audit.h>
@@ -860,6 +861,8 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
 		err = exec_permission_lite(inode);
 		if (err == -EAGAIN)
 			err = vfs_permission(nd, MAY_EXEC);
+		if (!err)
+			err = ima_path_check(&nd->path, MAY_EXEC);
  		if (err)
 			break;
 
@@ -1525,6 +1528,11 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
 	error = vfs_permission(nd, acc_mode);
 	if (error)
 		return error;
+
+	error = ima_path_check(&nd->path,
+			       acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC));
+	if (error)
+		return error;
 	/*
 	 * An append-only file must be opened in append mode for writing.
 	 */

include/linux/ima.h

@@ -0,0 +1,44 @@
+/*
+ * 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.
+ */
+
+#include <linux/fs.h>
+
+#ifndef _LINUX_IMA_H
+#define _LINUX_IMA_H
+
+static inline int ima_bprm_check(struct linux_binprm *bprm)
+{
+	return 0;
+}
+
+static inline int ima_inode_alloc(struct inode *inode)
+{
+	return 0;
+}
+
+static inline void ima_inode_free(struct inode *inode)
+{
+	return;
+}
+
+static inline int ima_path_check(struct path *path, int mask)
+{
+	return 0;
+}
+
+static inline void ima_file_free(struct file *file)
+{
+	return;
+}
+
+static inline int ima_file_mmap(struct file *file, unsigned long prot)
+{
+	return 0;
+}
+#endif /* _LINUX_IMA_H */

mm/mmap.c

@@ -20,6 +20,7 @@
 #include <linux/fs.h>
 #include <linux/personality.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/hugetlb.h>
 #include <linux/profile.h>
 #include <linux/module.h>
@@ -1048,6 +1049,9 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
 	}
 
 	error = security_file_mmap(file, reqprot, prot, flags, addr, 0);
+	if (error)
+		return error;
+	error = ima_file_mmap(file, prot);
 	if (error)
 		return error;