Re: [PATCH v1 1/1] dm-inlinecrypt: initialize blk-crypto key as HW-wrapped key

[Eric Biggers <ebiggers@kernel.org>]

On Tue, May 12, 2026 at 02:52:03AM -0700, Linlin Zhang wrote:
> dm-inlinecrypt currently initializes the blk-crypto key using
> BLK_CRYPTO_KEY_TYPE_RAW, which implies that the provided key material
> is a plaintext software key owned by the block layer.
> 
> However, on platforms where dm-inlinecrypt is used together with a
> hardware-backed key source (e.g. TrustZone/TEE or other secure key
> wrapping mechanisms), the key material passed down is already wrapped
> and must be treated as opaque by the block layer.
> 
> Initialize the blk-crypto key using BLK_CRYPTO_KEY_TYPE_HW_WRAPPED
> instead, so that dm-inlinecrypt correctly models hardware-wrapped keys
> and avoids incorrect assumptions about key ownership and visibility.
> 
> Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
> ---
>  drivers/md/dm-inlinecrypt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/md/dm-inlinecrypt.c b/drivers/md/dm-inlinecrypt.c
> index bd8e58a028c5..bcbf363c533a 100644
> --- a/drivers/md/dm-inlinecrypt.c
> +++ b/drivers/md/dm-inlinecrypt.c
> @@ -386,7 +386,7 @@ static int inlinecrypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
>  	dun_bytes = DIV_ROUND_UP(fls64(ctx->max_dun), 8);
>  
>  	err = blk_crypto_init_key(&ctx->key, raw_key, ctx->key_size,
> -				  BLK_CRYPTO_KEY_TYPE_RAW,
> +				  BLK_CRYPTO_KEY_TYPE_HW_WRAPPED,
>  				  cipher->mode_num, dun_bytes,
>  				  ctx->sector_size);

The raw key support is useful too, and it should be the default.
I recommend adding a "wrappedkey" optional argument that enables
BLK_CRYPTO_KEY_TYPE_HW_WRAPPED.

- Eric