module: replace copy_module_from_fd with kernel version

Replace copy_module_from_fd() with kernel_read_file_from_fd().

Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.

The security function security_kernel_module_from_file() was called prior
to reading a kernel module.  Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook.  Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.

This patch removes the security_kernel_module_from_file() hook and security
call.

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: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 0 insertions, 7 deletions

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index d32b7bd13635..cdee11cbcdf1 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -546,12 +546,6 @@
  *      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_module_from_file:
- *      Load a kernel module from userspace.
- *      @file contains the file structure pointing to the file containing
- *      the kernel module to load. If the module is being loaded from a blob,
- *      this argument will be NULL.
- *      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
@@ -1725,7 +1719,6 @@ struct security_hook_heads {
         struct list_head kernel_read_file;
         struct list_head kernel_post_read_file;
         struct list_head kernel_module_request;
-        struct list_head kernel_module_from_file;
         struct list_head task_fix_setuid;
         struct list_head task_setpgid;
         struct list_head task_getpgid;