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Commit 3e1be52d authored by Mimi Zohar's avatar Mimi Zohar
Browse files

security: imbed evm calls in security hooks 



Imbed the evm calls evm_inode_setxattr(), evm_inode_post_setxattr(),
evm_inode_removexattr() in the security hooks.  evm_inode_setxattr()
protects security.evm xattr.  evm_inode_post_setxattr() and
evm_inode_removexattr() updates the hmac associated with an inode.

(Assumes an LSM module protects the setting/removing of xattr.)

Changelog:
  - Don't define evm_verifyxattr(), unless CONFIG_INTEGRITY is enabled.
  - xattr_name is a 'const', value is 'void *'

Signed-off-by: default avatarMimi Zohar <zohar@us.ibm.com>
Acked-by: default avatarSerge Hallyn <serge.hallyn@ubuntu.com>
parent 6be5cc52

include/linux/evm.h

0 → 100644
+56 −0
Original line number Diff line number Diff line 
/*

 * evm.h

 *

 * Copyright (c) 2009 IBM Corporation

 * Author: Mimi Zohar <zohar@us.ibm.com>

 */



#ifndef _LINUX_EVM_H

#define _LINUX_EVM_H



#include <linux/integrity.h>



#ifdef CONFIG_EVM

extern enum integrity_status evm_verifyxattr(struct dentry *dentry,

					     const char *xattr_name,

					     void *xattr_value,

					     size_t xattr_value_len);

extern int evm_inode_setxattr(struct dentry *dentry, const char *name,

			      const void *value, size_t size);

extern void evm_inode_post_setxattr(struct dentry *dentry,

				    const char *xattr_name,

				    const void *xattr_value,

				    size_t xattr_value_len);

extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);

#else

#ifdef CONFIG_INTEGRITY

static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,

						    const char *xattr_name,

						    void *xattr_value,

						    size_t xattr_value_len)

{

	return INTEGRITY_UNKNOWN;

}

#endif



static inline int evm_inode_setxattr(struct dentry *dentry, const char *name,

				     const void *value, size_t size)

{

	return 0;

}



static inline void evm_inode_post_setxattr(struct dentry *dentry,

					   const char *xattr_name,

					   const void *xattr_value,

					   size_t xattr_value_len)

{

	return;

}



static inline int evm_inode_removexattr(struct dentry *dentry,

					const char *xattr_name)

{

	return 0;

}

#endif /* CONFIG_EVM_H */

#endif /* LINUX_EVM_H */

security/integrity/evm/evm_main.c

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/crypto.h>

#include <linux/xattr.h>

#include <linux/integrity.h>

#include <linux/evm.h>

#include "evm.h"



int evm_initialized;

security/security.c

+14 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/security.h>

#include <linux/integrity.h>

#include <linux/ima.h>

#include <linux/evm.h>



#define MAX_LSM_XATTR	1
@@ -580,9 +581,14 @@ int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 
int security_inode_setxattr(struct dentry *dentry, const char *name,

			    const void *value, size_t size, int flags)

{

	int ret;



	if (unlikely(IS_PRIVATE(dentry->d_inode)))

		return 0;

	return security_ops->inode_setxattr(dentry, name, value, size, flags);

	ret = security_ops->inode_setxattr(dentry, name, value, size, flags);

	if (ret)

		return ret;

	return evm_inode_setxattr(dentry, name, value, size);

}



void security_inode_post_setxattr(struct dentry *dentry, const char *name,
@@ -591,6 +597,7 @@ void security_inode_post_setxattr(struct dentry *dentry, const char *name, 
	if (unlikely(IS_PRIVATE(dentry->d_inode)))

		return;

	security_ops->inode_post_setxattr(dentry, name, value, size, flags);

	evm_inode_post_setxattr(dentry, name, value, size);

}



int security_inode_getxattr(struct dentry *dentry, const char *name)
@@ -609,9 +616,14 @@ int security_inode_listxattr(struct dentry *dentry) 


int security_inode_removexattr(struct dentry *dentry, const char *name)

{

	int ret;



	if (unlikely(IS_PRIVATE(dentry->d_inode)))

		return 0;

	return security_ops->inode_removexattr(dentry, name);

	ret = security_ops->inode_removexattr(dentry, name);

	if (ret)

		return ret;

	return evm_inode_removexattr(dentry, name);

}



int security_inode_need_killpriv(struct dentry *dentry)