linux-stable/include/linux/ima.h
Tyler Hicks 4834177e63 ima: Support additional conditionals in the KEXEC_CMDLINE hook function
Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLINE operation to
the rules in the IMA policy. This allows for some uniformity when
writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK,
and KEXEC_CMDLINE operations.

Prior to this patch, it was not possible to write a set of rules like
this:

 dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t
 dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t
 dont_measure func=KEXEC_CMDLINE obj_type=foo_t
 measure func=KEXEC_KERNEL_CHECK
 measure func=KEXEC_INITRAMFS_CHECK
 measure func=KEXEC_CMDLINE

The inode information associated with the kernel being loaded by a
kexec_kernel_load(2) syscall can now be included in the decision to
measure or not

Additonally, the uid, euid, and subj_* conditionals can also now be
used in KEXEC_CMDLINE rules. There was no technical reason as to why
those conditionals weren't being considered previously other than
ima_match_rules() didn't have a valid inode to use so it immediately
bailed out for KEXEC_CMDLINE operations rather than going through the
full list of conditional comparisons.

Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20 13:28:16 -04:00

170 lines
4.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2008 IBM Corporation
* Author: Mimi Zohar <zohar@us.ibm.com>
*/
#ifndef _LINUX_IMA_H
#define _LINUX_IMA_H
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
struct linux_binprm;
#ifdef CONFIG_IMA
extern int ima_bprm_check(struct linux_binprm *bprm);
extern int ima_file_check(struct file *file, int mask);
extern void ima_post_create_tmpfile(struct inode *inode);
extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot);
extern int ima_load_data(enum kernel_load_data_id id);
extern int ima_read_file(struct file *file, enum kernel_read_file_id id);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
extern void ima_post_path_mknod(struct dentry *dentry);
extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
#ifdef CONFIG_IMA_KEXEC
extern void ima_add_kexec_buffer(struct kimage *image);
#endif
#ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
extern bool arch_ima_get_secureboot(void);
extern const char * const *arch_get_ima_policy(void);
#else
static inline bool arch_ima_get_secureboot(void)
{
return false;
}
static inline const char * const *arch_get_ima_policy(void)
{
return NULL;
}
#endif
#else
static inline int ima_bprm_check(struct linux_binprm *bprm)
{
return 0;
}
static inline int ima_file_check(struct file *file, int mask)
{
return 0;
}
static inline void ima_post_create_tmpfile(struct inode *inode)
{
}
static inline void ima_file_free(struct file *file)
{
return;
}
static inline int ima_file_mmap(struct file *file, unsigned long prot)
{
return 0;
}
static inline int ima_file_mprotect(struct vm_area_struct *vma,
unsigned long prot)
{
return 0;
}
static inline int ima_load_data(enum kernel_load_data_id id)
{
return 0;
}
static inline int ima_read_file(struct file *file, enum kernel_read_file_id id)
{
return 0;
}
static inline int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id)
{
return 0;
}
static inline void ima_post_path_mknod(struct dentry *dentry)
{
return;
}
static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size)
{
return -EOPNOTSUPP;
}
static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {}
#endif /* CONFIG_IMA */
#ifndef CONFIG_IMA_KEXEC
struct kimage;
static inline void ima_add_kexec_buffer(struct kimage *image)
{}
#endif
#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
extern void ima_post_key_create_or_update(struct key *keyring,
struct key *key,
const void *payload, size_t plen,
unsigned long flags, bool create);
#else
static inline void ima_post_key_create_or_update(struct key *keyring,
struct key *key,
const void *payload,
size_t plen,
unsigned long flags,
bool create) {}
#endif /* CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS */
#ifdef CONFIG_IMA_APPRAISE
extern bool is_ima_appraise_enabled(void);
extern void ima_inode_post_setattr(struct dentry *dentry);
extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
const void *xattr_value, size_t xattr_value_len);
extern int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name);
#else
static inline bool is_ima_appraise_enabled(void)
{
return 0;
}
static inline void ima_inode_post_setattr(struct dentry *dentry)
{
return;
}
static inline int ima_inode_setxattr(struct dentry *dentry,
const char *xattr_name,
const void *xattr_value,
size_t xattr_value_len)
{
return 0;
}
static inline int ima_inode_removexattr(struct dentry *dentry,
const char *xattr_name)
{
return 0;
}
#endif /* CONFIG_IMA_APPRAISE */
#if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
extern bool ima_appraise_signature(enum kernel_read_file_id func);
#else
static inline bool ima_appraise_signature(enum kernel_read_file_id func)
{
return false;
}
#endif /* CONFIG_IMA_APPRAISE && CONFIG_INTEGRITY_TRUSTED_KEYRING */
#endif /* _LINUX_IMA_H */