Re: [PATCH 3/6] firmware: differentiate between signed regulatory.db and other firmware

[Luis R. Rodriguez]

On Tue, May 01, 2018 at 09:48:20AM -0400, Mimi Zohar wrote:
> Allow LSMs and IMA to differentiate between signed regulatory.db and
> other firmware.
> 
> Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
> Cc: Luis R. Rodriguez <mcgrof@xxxxxxxx>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
> Cc: Johannes Berg <johannes.berg@xxxxxxxxx>
> ---
>  drivers/base/firmware_loader/main.c | 5 +++++
>  include/linux/fs.h                  | 1 +
>  2 files changed, 6 insertions(+)
> 
> diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
> index eb34089e4299..d7cdf04a8681 100644
> --- a/drivers/base/firmware_loader/main.c
> +++ b/drivers/base/firmware_loader/main.c
> @@ -318,6 +318,11 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
>  			break;
>  		}
>  
> +#ifdef CONFIG_CFG80211_REQUIRE_SIGNED_REGDB
> +		if ((strcmp(fw_priv->fw_name, "regulatory.db") == 0) ||
> +		    (strcmp(fw_priv->fw_name, "regulatory.db.p7s") == 0))
> +			id = READING_FIRMWARE_REGULATORY_DB;
> +#endif

Whoa, no way.

>  		fw_priv->size = 0;
>  		rc = kernel_read_file_from_path(path, &fw_priv->data, &size,
>  						msize, id);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index dc16a73c3d38..d1153c2884b9 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2811,6 +2811,7 @@ extern int do_pipe_flags(int *, int);
>  	id(FIRMWARE, firmware)		\
>  	id(FIRMWARE_PREALLOC_BUFFER, firmware)	\
>  	id(FIRMWARE_FALLBACK, firmware)	\
> +	id(FIRMWARE_REGULATORY_DB, firmware)	\

Why could IMA not appriase these files? They are part of the standard path.

  Luis

>  	id(MODULE, kernel-module)		\
>  	id(KEXEC_IMAGE, kexec-image)		\
>  	id(KEXEC_INITRAMFS, kexec-initramfs)	\
> -- 
> 2.7.5
> 
> 

-- 
Do not panic