[PATCH v1 0/1] dm-inlinecrypt: move to HW-wrapped key

[PATCH v1 0/1] dm-inlinecrypt: move to HW-wrapped key

[Linlin Zhang]

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.

This was requested as the first version in the link
(https://lore.kernel.org/all/20260312070110.GD2359@sol/) to have a
a easy way validating the patch.

However, now support for wrapped keys is already upstream and
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.

Switching the blk-crypto key initialization to
BLK_CRYPTO_KEY_TYPE_HW_WRAPPED aligns dm-inlinecrypt
with hardware-backed key usage models and avoids incorrect assumptions
about key ownership and visibility.

Linlin Zhang (1):
  dm-inlinecrypt: initialize blk-crypto key as HW-wrapped key

 drivers/md/dm-inlinecrypt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.34.1

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

[Linlin Zhang]

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);
 	if (err) {
-- 
2.34.1

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

[Eric Biggers]

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

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

[Eric Biggers]

On Tue, May 12, 2026 at 06:53:35PM +0000, Eric Biggers wrote:
> 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.

This patch also makes the variable called "raw_key" contain a key that
isn't a raw key, which is confusing.  "key_bytes" would make more sense
for a byte array that can contain either type of key.  See e.g.
blk_crypto_init_key() which uses that naming convention.

- Eric