Quoting Kees Cook (keesc...@chromium.org):
> Now that kernel module origins can be reasoned about, provide a hook to
> the LSMs to make policy decisions about the module file.
>
> Signed-off-by: Kees Cook <keesc...@chromium.org>
Acked-by: Serge E. Hallyn <serge.hal...@canonical.com>
> ---
> include/linux/security.h | 11 +++++++++++
> kernel/module.c | 7 +++++++
> security/capability.c | 6 ++++++
> security/security.c | 5 +++++
> 4 files changed, 29 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 3dea6a9..634d09a 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -693,6 +693,10 @@ static inline void security_free_mnt_opts(struct
> security_mnt_opts *opts)
> * 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 new kernel module from a file.
> + * @file contains the file structure being loaded as a kernel module.
> + * Return 0 if permission is granted.
> * @task_fix_setuid:
> * Update the module's state after setting one or more of the user
> * identity attributes of the current process. The @flags parameter
> @@ -1507,6 +1511,7 @@ struct security_operations {
> 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_module_from_file)(struct file *file);
> int (*task_fix_setuid) (struct cred *new, const struct cred *old,
> int flags);
> int (*task_setpgid) (struct task_struct *p, pid_t pgid);
> @@ -1764,6 +1769,7 @@ void security_transfer_creds(struct cred *new, const
> struct cred *old);
> 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_module_from_file(struct file *file);
> 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);
> @@ -2277,6 +2283,11 @@ static inline int security_kernel_module_request(char
> *kmod_name)
> return 0;
> }
>
> +static inline int security_kernel_module_from_file(struct file *file)
> +{
> + return 0;
> +}
> +
> static inline int security_task_fix_setuid(struct cred *new,
> const struct cred *old,
> int flags)
> diff --git a/kernel/module.c b/kernel/module.c
> index 0be8c11..1fcc63f 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -29,6 +29,7 @@
> #include <linux/vmalloc.h>
> #include <linux/elf.h>
> #include <linux/proc_fs.h>
> +#include <linux/security.h>
> #include <linux/seq_file.h>
> #include <linux/syscalls.h>
> #include <linux/fcntl.h>
> @@ -2447,6 +2448,12 @@ static Elf_Ehdr *copy_module_from_fd(unsigned int fd,
> unsigned long *len)
> }
> size = stat.size;
>
> + err = security_kernel_module_from_file(file);
> + if (err) {
> + hdr = ERR_PTR(err);
> + goto out;
> + }
> +
> hdr = vmalloc(size);
> if (!hdr) {
> hdr = ERR_PTR(-ENOMEM);
> diff --git a/security/capability.c b/security/capability.c
> index 61095df..8acb304 100644
> --- a/security/capability.c
> +++ b/security/capability.c
> @@ -395,6 +395,11 @@ static int cap_kernel_module_request(char *kmod_name)
> return 0;
> }
>
> +static int cap_kernel_module_from_file(struct file *file)
> +{
> + return 0;
> +}
> +
> static int cap_task_setpgid(struct task_struct *p, pid_t pgid)
> {
> return 0;
> @@ -967,6 +972,7 @@ void __init security_fixup_ops(struct security_operations
> *ops)
> set_to_cap_if_null(ops, kernel_act_as);
> set_to_cap_if_null(ops, kernel_create_files_as);
> set_to_cap_if_null(ops, kernel_module_request);
> + set_to_cap_if_null(ops, kernel_module_from_file);
> set_to_cap_if_null(ops, task_fix_setuid);
> set_to_cap_if_null(ops, task_setpgid);
> set_to_cap_if_null(ops, task_getpgid);
> diff --git a/security/security.c b/security/security.c
> index 860aeb3..f7f8695 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -799,6 +799,11 @@ int security_kernel_module_request(char *kmod_name)
> return security_ops->kernel_module_request(kmod_name);
> }
>
> +int security_kernel_module_from_file(struct file *file)
> +{
> + return security_ops->kernel_module_from_file(file);
> +}
> +
> int security_task_fix_setuid(struct cred *new, const struct cred *old,
> int flags)
> {
> --
> 1.7.0.4
>
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