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, 12 deletions

diff --git a/security/security.c b/security/security.c
index 8e699f98a600..3644b0344d29 100644
--- a/security/security.c
+++ b/security/security.c
@@ -889,16 +889,6 @@ int security_kernel_module_request(char *kmod_name)
         return call_int_hook(kernel_module_request, 0, kmod_name);
 }
 
-int security_kernel_module_from_file(struct file *file)
-{
-        int ret;
-
-        ret = call_int_hook(kernel_module_from_file, 0, file);
-        if (ret)
-                return ret;
-        return ima_module_check(file);
-}
-
 int security_kernel_read_file(struct file *file, enum kernel_read_file_id id)
 {
         int ret;
@@ -1705,8 +1695,6 @@ struct security_hook_heads security_hook_heads = {
                 LIST_HEAD_INIT(security_hook_heads.kernel_create_files_as),
         .kernel_module_request =
                 LIST_HEAD_INIT(security_hook_heads.kernel_module_request),
-        .kernel_module_from_file =
-                LIST_HEAD_INIT(security_hook_heads.kernel_module_from_file),
         .kernel_read_file =
                 LIST_HEAD_INIT(security_hook_heads.kernel_read_file),
         .kernel_post_read_file =