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Commit bc8ca5b9 authored by Mimi Zohar's avatar Mimi Zohar
Browse files

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: default avatarMimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarLuis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
parent b44a7dfc

fs/exec.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

include/linux/fs.h

+6 −1
Original line number Diff line number Diff line
@@ -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 *);

include/linux/lsm_hooks.h

+3 −1
Original line number Diff line number Diff line
@@ -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);

include/linux/security.h

+5 −2
Original line number Diff line number Diff line
@@ -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;

}

security/security.c

+3 −2
Original line number Diff line number Diff line
@@ -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);