[U-Boot] [PATCH 2/6] efi_loader: Fix memory map size check to avoid out-of-bounds access

[Alexander Graf]

On 30.09.16 02:03, Stefan Brüns wrote:
> memory_map_size as IN parameter specifies the size of the provided buffer.
> If the buffer is to small, memory_map_size is updated to indicate the
> required size, and an error code is returned.
> 
> Signed-off-by: Stefan Brüns <stefan.bruens at rwth-aachen.de>

This patch doesn't actually change anything, does it?


Alex

> ---
>  lib/efi_loader/efi_memory.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index ebe8e94..5d71fdf 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -342,16 +342,18 @@ efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
>  
>  	map_size = map_entries * sizeof(struct efi_mem_desc);
>  
> -	*memory_map_size = map_size;
> -
>  	if (descriptor_size)
>  		*descriptor_size = sizeof(struct efi_mem_desc);
>  
>  	if (descriptor_version)
>  		*descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
>  
> -	if (*memory_map_size < map_size)
> +	if (*memory_map_size < map_size) {
> +		*memory_map_size = map_size;
>  		return EFI_BUFFER_TOO_SMALL;
> +	}
> +
> +	*memory_map_size = map_size;
>  
>  	/* Copy list into array */
>  	if (memory_map) {
>