vfs: define kernel_read_file_id enumeration

To differentiate between the kernel_read_file() callers, this patch
defines a new enumeration named kernel_read_file_id and includes the
caller identifier as an argument.

Subsequent patches define READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS,
READING_FIRMWARE, READING_MODULE, and READING_POLICY.

Changelog v3:
- Replace the IMA specific enumeration with a generic one.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Mimi Zohar 2016-01-24 10:07:32 -05:00
parent b44a7dfc6f
commit bc8ca5b92d
5 changed files with 19 additions and 8 deletions

View File

@ -833,7 +833,7 @@ int kernel_read(struct file *file, loff_t offset,
EXPORT_SYMBOL(kernel_read);
int kernel_read_file(struct file *file, void **buf, loff_t *size,
loff_t max_size)
loff_t max_size, enum kernel_read_file_id id)
{
loff_t i_size, pos;
ssize_t bytes = 0;
@ -871,7 +871,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
goto out;
}
ret = security_kernel_post_read_file(file, *buf, i_size);
ret = security_kernel_post_read_file(file, *buf, i_size, id);
if (!ret)
*size = pos;

View File

@ -2576,8 +2576,13 @@ static inline void i_readcount_inc(struct inode *inode)
#endif
extern int do_pipe_flags(int *, int);
enum kernel_read_file_id {
READING_MAX_ID
};
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
extern int kernel_read_file(struct file *, void **, loff_t *, loff_t);
extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
enum kernel_read_file_id);
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
extern struct file * open_exec(const char *);

View File

@ -567,6 +567,7 @@
* by the kernel.
* @buf pointer to buffer containing the file contents.
* @size length of the file contents.
* @id kernel read file identifier
* Return 0 if permission is granted.
* @task_fix_setuid:
* Update the module's state after setting one or more of the user
@ -1464,7 +1465,8 @@ union security_list_options {
int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size);
int (*kernel_module_request)(char *kmod_name);
int (*kernel_module_from_file)(struct file *file);
int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size);
int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
int (*task_fix_setuid)(struct cred *new, const struct cred *old,
int flags);
int (*task_setpgid)(struct task_struct *p, pid_t pgid);

View File

@ -28,6 +28,7 @@
#include <linux/err.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/fs.h>
struct linux_binprm;
struct cred;
@ -301,7 +302,8 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_fw_from_file(struct file *file, char *buf, size_t size);
int security_kernel_module_request(char *kmod_name);
int security_kernel_module_from_file(struct file *file);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
int security_task_fix_setuid(struct cred *new, const struct cred *old,
int flags);
int security_task_setpgid(struct task_struct *p, pid_t pgid);
@ -868,7 +870,8 @@ static inline int security_kernel_module_from_file(struct file *file)
}
static inline int security_kernel_post_read_file(struct file *file,
char *buf, loff_t size)
char *buf, loff_t size,
enum kernel_read_file_id id)
{
return 0;
}

View File

@ -910,9 +910,10 @@ int security_kernel_module_from_file(struct file *file)
return ima_module_check(file);
}
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size)
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id)
{
return call_int_hook(kernel_post_read_file, 0, file, buf, size);
return call_int_hook(kernel_post_read_file, 0, file, buf, size, id);
}
EXPORT_SYMBOL_GPL(security_kernel_post_read_file);