Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

security: define new LSM hook named security_kernel_load_data

Browse source 
Differentiate between the kernel reading a file specified by userspace
from the kernel loading a buffer containing data provided by userspace.
This patch defines a new LSM hook named security_kernel_load_data().

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
This commit is contained in:
Mimi Zohar 2018-07-13 14:05:56 -04:00 committed by James Morris
parent 57b54d74dd
commit 377179cd28
3 changed files with 38 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
include/linux/lsm_hooks.h
View file

@ -576,6 +576,10 @@
* userspace to load a kernel module with the given name.
* @kmod_name name of the module requested by the kernel
* Return 0 if successful.
* @kernel_load_data:
* Load data provided by userspace.
* @id kernel load data identifier
* Return 0 if permission is granted.
* @kernel_read_file:
* Read a file specified by userspace.
* @file contains the file structure pointing to the file being read
@ -1582,6 +1586,7 @@ union security_list_options {
int (*kernel_act_as)(struct cred *new, u32 secid);
int (*kernel_create_files_as)(struct cred *new, struct inode *inode);
int (*kernel_module_request)(char *kmod_name);
int (*kernel_load_data)(enum kernel_load_data_id id);
int (*kernel_read_file)(struct file *file, enum kernel_read_file_id id);
int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
@ -1872,6 +1877,7 @@ struct security_hook_heads {
struct hlist_head cred_getsecid;
struct hlist_head kernel_act_as;
struct hlist_head kernel_create_files_as;
struct hlist_head kernel_load_data;
struct hlist_head kernel_read_file;
struct hlist_head kernel_post_read_file;
struct hlist_head kernel_module_request;

27
include/linux/security.h
View file

@ -159,6 +159,27 @@ extern int mmap_min_addr_handler(struct ctl_table *table, int write,
typedef int (*initxattrs) (struct inode *inode,
const struct xattr *xattr_array, void *fs_data);
/* Keep the kernel_load_data_id enum in sync with kernel_read_file_id */
#define __data_id_enumify(ENUM, dummy) LOADING_ ## ENUM,
#define __data_id_stringify(dummy, str) #str,
enum kernel_load_data_id {
__kernel_read_file_id(__data_id_enumify)
};
static const char * const kernel_load_data_str[] = {
__kernel_read_file_id(__data_id_stringify)
};
static inline const char *kernel_load_data_id_str(enum kernel_load_data_id id)
{
if ((unsigned)id >= LOADING_MAX_ID)
return kernel_load_data_str[LOADING_UNKNOWN];
return kernel_load_data_str[id];
}
#ifdef CONFIG_SECURITY
struct security_mnt_opts {
@ -320,6 +341,7 @@ void security_cred_getsecid(const struct cred *c, u32 *secid);
int security_kernel_act_as(struct cred *new, u32 secid);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_module_request(char *kmod_name);
int security_kernel_load_data(enum kernel_load_data_id id);
int security_kernel_read_file(struct file *file, enum kernel_read_file_id id);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id);
@ -909,6 +931,11 @@ static inline int security_kernel_module_request(char *kmod_name)
return 0;
}
static inline int security_kernel_load_data(enum kernel_load_data_id id)
{
return 0;
}
static inline int security_kernel_read_file(struct file *file,
enum kernel_read_file_id id)
{

5
security/security.c
View file

@ -1056,6 +1056,11 @@ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
}
EXPORT_SYMBOL_GPL(security_kernel_post_read_file);
int security_kernel_load_data(enum kernel_load_data_id id)
{
return call_int_hook(kernel_load_data, 0, id);
}
int security_task_fix_setuid(struct cred *new, const struct cred *old,
int flags)
{