Re: [PATCH 03/13] fs/kernel_read_file: Remove FIRMWARE_EFI_EMBEDDED enum

[Scott Branden]

On 2020-07-17 10:42 a.m., Kees Cook wrote:
> The "FIRMWARE_EFI_EMBEDDED" enum is a "where", not a "what". It
> should not be distinguished separately from just "FIRMWARE", as this
> confuses the LSMs about what is being loaded. Additionally, there was
> no actual validation of the firmware contents happening.
>
> Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firmware_request_platform()")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
> ---
> To aid in backporting, this change is made before moving
> kernel_read_file() to separate header/source files.
> ---
>   drivers/base/firmware_loader/fallback_platform.c | 2 +-
>   include/linux/fs.h                               | 3 +--
>   2 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
> index 685edb7dd05a..6958ab1a8059 100644
> --- a/drivers/base/firmware_loader/fallback_platform.c
> +++ b/drivers/base/firmware_loader/fallback_platform.c
> @@ -17,7 +17,7 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
>   	if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
>   		return -ENOENT;
>   
> -	rc = security_kernel_load_data(LOADING_FIRMWARE_EFI_EMBEDDED);
> +	rc = security_kernel_load_data(LOADING_FIRMWARE);
>   	if (rc)
>   		return rc;
>   
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 95fc775ed937..f50a35d54a61 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2993,11 +2993,10 @@ static inline void i_readcount_inc(struct inode *inode)
>   #endif
>   extern int do_pipe_flags(int *, int);
>   
> -/* This is a list of *what* is being read, not *how*. */
> +/* This is a list of *what* is being read, not *how* nor *where*. */
>   #define __kernel_read_file_id(id) \
>   	id(UNKNOWN, unknown)		\
>   	id(FIRMWARE, firmware)		\
> -	id(FIRMWARE_EFI_EMBEDDED, firmware)	\
>   	id(MODULE, kernel-module)		\
>   	id(KEXEC_IMAGE, kexec-image)		\
>   	id(KEXEC_INITRAMFS, kexec-initramfs)	\