security: define new LSM hook named security_kernel_load_data

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>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 8f1131c8dd54..a08bc2587b96 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -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;