linux-stable/include/linux/evm.h
Stefan Berger a652aa5906 evm: Store and detect metadata inode attributes changes
On stacked filesystem the metadata inode may be different than the one
file data inode and therefore changes to it need to be detected
independently. Therefore, store the i_version, device number, and inode
number associated with the file metadata inode.

Implement a function to detect changes to the inode and if a change is
detected reset the evm_status. This function will be called by IMA when
IMA detects that the metadata inode is different from the file's inode.

Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-04-09 17:14:57 -04:00

89 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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>
#include <linux/xattr.h>
#ifdef CONFIG_EVM
extern int evm_set_key(void *key, size_t keylen);
extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
const char *xattr_name,
void *xattr_value,
size_t xattr_value_len);
int evm_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, struct xattr *xattrs,
int *xattr_count);
extern bool evm_revalidate_status(const char *xattr_name);
extern int evm_protected_xattr_if_enabled(const char *req_xattr_name);
extern int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer,
int buffer_size, char type,
bool canonical_fmt);
extern bool evm_metadata_changed(struct inode *inode,
struct inode *metadata_inode);
#ifdef CONFIG_FS_POSIX_ACL
extern int posix_xattr_acl(const char *xattrname);
#else
static inline int posix_xattr_acl(const char *xattrname)
{
return 0;
}
#endif
#else
static inline int evm_set_key(void *key, size_t keylen)
{
return -EOPNOTSUPP;
}
#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_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr,
struct xattr *xattrs,
int *xattr_count)
{
return 0;
}
static inline bool evm_revalidate_status(const char *xattr_name)
{
return false;
}
static inline int evm_protected_xattr_if_enabled(const char *req_xattr_name)
{
return false;
}
static inline int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer,
int buffer_size, char type,
bool canonical_fmt)
{
return -EOPNOTSUPP;
}
static inline bool evm_metadata_changed(struct inode *inode,
struct inode *metadata_inode)
{
return false;
}
#endif /* CONFIG_EVM */
#endif /* LINUX_EVM_H */