[PATCH v3] barebox: Fix excessive loading of FIT images

[Sascha Hauer]

On Fri, May 19, 2023 at 02:10:28PM +0200, Ahmad Fatoum wrote:
> From: Christian Melki <christian.melki at t2data.com>
> 
> Barebox doesn't use the FIT image size from the header
> when loading FIT images. It bluntly assumes that the FIT image
> is equal to the file size. Which would be true if the
> FIT image is a file. But if it's situated on a raw device,
> then barebox proceeds to load the entire contents of that
> raw device, only to conclude that it only needed parts of it.
> Fix it.
> 
> Cc: Daniel Brát <danek.brat at gmail.com>
> Signed-off-by: Christian Melki <christian.melki at t2data.com>
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---

Applied, thanks

Sascha

> v3 was here: https://lore.barebox.org/barebox/20220729205441.9512-1-danek.brat@gmail.com/
> v2 -> v3:
>  - restrict change to bootm_open_fit
>  - use cached data in struct image_data
> v1 -> v2:
>  - use fdt32_to_cpu to read the totalsize from header
> ---
>  common/bootm.c      | 9 ++++++++-
>  common/image-fit.c  | 7 ++++---
>  include/image-fit.h | 2 +-
>  3 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/common/bootm.c b/common/bootm.c
> index fb1ed36a26dc..91a6e1688674 100644
> --- a/common/bootm.c
> +++ b/common/bootm.c
> @@ -522,13 +522,20 @@ static int bootm_open_os_uimage(struct image_data *data)
>  static int bootm_open_fit(struct image_data *data)
>  {
>  	struct fit_handle *fit;
> +	struct fdt_header *header;
>  	static const char *kernel_img = "kernel";
> +	size_t flen, hlen;
>  	int ret;
>  
>  	if (!IS_ENABLED(CONFIG_FITIMAGE))
>  		return 0;
>  
> -	fit = fit_open(data->os_file, data->verbose, data->verify);
> +	header = (struct fdt_header *)data->os_header;
> +	flen = bootm_get_os_size(data);
> +	hlen = fdt32_to_cpu(header->totalsize);
> +
> +	fit = fit_open(data->os_file, data->verbose, data->verify,
> +		       min(flen, hlen));
>  	if (IS_ERR(fit)) {
>  		pr_err("Loading FIT image %s failed with: %pe\n", data->os_file, fit);
>  		return PTR_ERR(fit);
> diff --git a/common/image-fit.c b/common/image-fit.c
> index 3e6e7fbd6d12..9bea62bb34a0 100644
> --- a/common/image-fit.c
> +++ b/common/image-fit.c
> @@ -827,6 +827,7 @@ struct fit_handle *fit_open_buf(const void *buf, size_t size, bool verbose,
>   * @filename:	The filename of the FIT image
>   * @verbose:	If true, be more verbose
>   * @verify:	The verify mode
> + * @max_size:	maximum length to read from file
>   *
>   * This opens a FIT image found in @filename. The returned handle is used as
>   * context for the other FIT functions.
> @@ -834,7 +835,7 @@ struct fit_handle *fit_open_buf(const void *buf, size_t size, bool verbose,
>   * Return: A handle to a FIT image or a ERR_PTR
>   */
>  struct fit_handle *fit_open(const char *filename, bool verbose,
> -			    enum bootm_verify verify)
> +			    enum bootm_verify verify, loff_t max_size)
>  {
>  	struct fit_handle *handle;
>  	int ret;
> @@ -845,8 +846,8 @@ struct fit_handle *fit_open(const char *filename, bool verbose,
>  	handle->verify = verify;
>  
>  	ret = read_file_2(filename, &handle->size, &handle->fit_alloc,
> -			  FILESIZE_MAX);
> -	if (ret) {
> +			  max_size);
> +	if (ret && ret != -EFBIG) {
>  		pr_err("unable to read %s: %s\n", filename, strerror(-ret));
>  		return ERR_PTR(ret);
>  	}
> diff --git a/include/image-fit.h b/include/image-fit.h
> index f21545988e16..0b8e94bf4635 100644
> --- a/include/image-fit.h
> +++ b/include/image-fit.h
> @@ -23,7 +23,7 @@ struct fit_handle {
>  };
>  
>  struct fit_handle *fit_open(const char *filename, bool verbose,
> -			    enum bootm_verify verify);
> +			    enum bootm_verify verify, loff_t max_size);
>  struct fit_handle *fit_open_buf(const void *buf, size_t len, bool verbose,
>  				enum bootm_verify verify);
>  void *fit_open_configuration(struct fit_handle *handle, const char *name);
> -- 
> 2.39.2
> 
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |