[PATCH 2/2] partitions: efi: Fix MAX_PARTITION check

[Ahmad Fatoum]

On 02.06.21 09:15, Sascha Hauer wrote:
> The GPT partiton parser has a check which should check if the GPT has
> more partitions than we support. This doesn't work because the loop
> iterating over the partitions exits with a maximum i of MAX_PARTITION,
> i > MAX_PARTITION will never be true. Fix the check.
> 
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>

Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

> ---
>  common/partitions/efi.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/common/partitions/efi.c b/common/partitions/efi.c
> index 437c3d64f8..135b08901a 100644
> --- a/common/partitions/efi.c
> +++ b/common/partitions/efi.c
> @@ -446,7 +446,14 @@ static void efi_partition(void *buf, struct block_device *blk,
>  	}
>  
>  	nb_part = le32_to_cpu(gpt->num_partition_entries);
> -	for (i = 0; i < MAX_PARTITION && i < nb_part; i++) {
> +
> +	if (nb_part > MAX_PARTITION) {
> +		dev_warn(blk->dev, "GPT has more partitions than we support (%d) > max partition number (%d)\n",
> +			 nb_part, MAX_PARTITION);
> +		nb_part = MAX_PARTITION;
> +	}
> +
> +	for (i = 0; i < nb_part; i++) {
>  		if (!is_pte_valid(&ptes[i], last_lba(blk))) {
>  			dev_dbg(blk->dev, "Invalid pte %d\n", i);
>  			return;
> @@ -460,10 +467,6 @@ static void efi_partition(void *buf, struct block_device *blk,
>  		snprintf(pentry->partuuid, sizeof(pentry->partuuid), "%pUl", &ptes[i].unique_partition_guid);
>  		pd->used_entries++;
>  	}
> -
> -	if (i > MAX_PARTITION)
> -		dev_warn(blk->dev, "num_partition_entries (%d) > max partition number (%d)\n",
> -			 nb_part, MAX_PARTITION);
>  }
>  
>  static struct partition_parser efi_partition_parser = {
> 

-- 
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 |