[U-Boot] [PATCH 2/3] efi: add protection for block_dev

[Heinrich Schuchardt <xypron.glpk@gmx.de>]

On 4/10/19 11:02 AM, Patrick Delaunay wrote:
> Check the value of block_dev before to use this pointer.
>
> This patch solves problem for the command "load" when ubifs
> is previously mounted: in this case the function
> blk_get_device_part_str("ubi 0") don't return error but return
> block_dev = NULL and then data abort.
>
> Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Added to efi-2019-07 branch.

> ---
>
> To reproduce the issue, I have a boot script 'boot.scr.uimg'
> with a load command executed during ubi boot:
>
> load ${devtype} ${devnum}:${distro_bootpart} ${m4fw_addr} ${m4fw_name}
>
> I have a data abort for call stack:
> - do_load_wrapper for "ubi 0"
> -- efi_set_bootdev
> --- efi_dp_from_name
>
> => desc = 0 and data abort for access to 'desc->*'
>
> I also proposed a protection for the same issue in ums command
> http://patchwork.ozlabs.org/project/uboot/list/?series=68096
>
>
>   lib/efi_loader/efi_device_path.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> index 53b40c8..fd57be8 100644
> --- a/lib/efi_loader/efi_device_path.c
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -970,7 +970,7 @@ efi_status_t efi_dp_from_name(const char *dev, const char *devnr,
>   	if (!is_net) {
>   		part = blk_get_device_part_str(dev, devnr, &desc, &fs_partition,
>   					       1);
> -		if (part < 0)
> +		if (part < 0 || !desc)
>   			return EFI_INVALID_PARAMETER;
>
>   		if (device)
>