[PATCH 1/6] integrity: IMA hooks

From: Mimi Zohar
Date: Thu Jan 29 2009 - 17:26:11 EST


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.

- renamed integrity hooks to ima
- additional ima_path_check() in open_exec() and __link_path_walk()
required for maintaining readcount
- removed Kconfig additions/changes

Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxx>
Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
---
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d8362cf..40c51e9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/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.
diff --git a/fs/exec.c b/fs/exec.c
index 0dd60a0..febfd8e 100644
--- a/fs/exec.c
+++ b/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>
@@ -127,6 +128,9 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
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;

file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
error = PTR_ERR(file);
@@ -674,6 +678,9 @@ struct file *open_exec(const char *name)
err = inode_permission(nd.path.dentry->d_inode, 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;

file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
if (IS_ERR(file))
@@ -1168,6 +1175,9 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
retval = security_bprm_check(bprm);
if (retval)
return retval;
+ retval = ima_bprm_check(bprm);
+ if (retval)
+ return retval;

/* kernel module loader fixup */
/* so we don't try to load run modprobe in kernel space. */
diff --git a/fs/file_table.c b/fs/file_table.c
index bbeeac6..da806ac 100644
--- a/fs/file_table.c
+++ b/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>
@@ -279,6 +280,7 @@ 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);
diff --git a/fs/inode.c b/fs/inode.c
index 913ab2d..40e37c0 100644
--- a/fs/inode.c
+++ b/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>
@@ -147,13 +148,13 @@ 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);
@@ -189,6 +190,15 @@ 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);

diff --git a/fs/namei.c b/fs/namei.c
index bbc15c2..f9bfc8d 100644
--- a/fs/namei.c
+++ b/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>
@@ -850,6 +851,8 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
if (err == -EAGAIN)
err = inode_permission(nd->path.dentry->d_inode,
MAY_EXEC);
+ if (!err)
+ err = ima_path_check(&nd->path, MAY_EXEC);
if (err)
break;

@@ -1509,6 +1512,11 @@ int may_open(struct path *path, int acc_mode, int flag)
error = inode_permission(inode, acc_mode);
if (error)
return error;
+
+ error = ima_path_check(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.
*/
diff --git a/include/linux/ima.h b/include/linux/ima.h
new file mode 100644
index 0000000..4ed1e4d
--- /dev/null
+++ b/include/linux/ima.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2008 IBM Corporation
+ * Author: Mimi Zohar <zohar@xxxxxxxxxx>
+ *
+ * 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 */
diff --git a/mm/mmap.c b/mm/mmap.c
index 8d95902..d36a587 100644
--- a/mm/mmap.c
+++ b/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>
@@ -1049,6 +1050,9 @@ 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;

return mmap_region(file, addr, len, flags, vm_flags, pgoff,
accountable);
--
1.5.6.6

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