diff mbox series

[RFC,3/7] tee: add private login method for kernel clients

Message ID 1560421833-27414-4-git-send-email-sumit.garg@linaro.org
State New
Headers show
Series Introduce TEE based Trusted Keys support | expand

Commit Message

Sumit Garg June 13, 2019, 10:30 a.m. UTC
There are use-cases where user-space shouldn't be allowed to communicate
directly with a TEE device which is dedicated to provide a specific
service for a kernel client. So add a private login method for kernel
clients and disallow user-space to open-session using this login method.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

---
 drivers/tee/tee_core.c   | 6 ++++++
 include/uapi/linux/tee.h | 2 ++
 2 files changed, 8 insertions(+)

-- 
2.7.4

Comments

Jens Wiklander July 8, 2019, 3:39 p.m. UTC | #1
Hi Sumit,

On Thu, Jun 13, 2019 at 04:00:29PM +0530, Sumit Garg wrote:
> There are use-cases where user-space shouldn't be allowed to communicate

> directly with a TEE device which is dedicated to provide a specific

> service for a kernel client. So add a private login method for kernel

> clients and disallow user-space to open-session using this login method.

> 

> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

> ---

>  drivers/tee/tee_core.c   | 6 ++++++

>  include/uapi/linux/tee.h | 2 ++

>  2 files changed, 8 insertions(+)

> 

> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c

> index 0f16d9f..4581bd1 100644

> --- a/drivers/tee/tee_core.c

> +++ b/drivers/tee/tee_core.c

> @@ -334,6 +334,12 @@ static int tee_ioctl_open_session(struct tee_context *ctx,

>  			goto out;

>  	}

>  

> +	if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {

TEE_IOCTL_LOGIN_REE_KERNEL is defined as 0x80000000 which is in the
range specified and implementation defined by the GP spec. I wonder if
we shouldn't filter the entire implementation defined range instead of
just this value.

> +		pr_err("login method not allowed for user-space client\n");

pr_debug(), if it's needed at all.

> +		rc = -EPERM;

> +		goto out;

> +	}

> +

>  	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);

>  	if (rc)

>  		goto out;

> diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h

> index 4b9eb06..f33c69c 100644

> --- a/include/uapi/linux/tee.h

> +++ b/include/uapi/linux/tee.h

> @@ -172,6 +172,8 @@ struct tee_ioctl_buf_data {

>  #define TEE_IOCTL_LOGIN_APPLICATION		4

>  #define TEE_IOCTL_LOGIN_USER_APPLICATION	5

>  #define TEE_IOCTL_LOGIN_GROUP_APPLICATION	6

> +/* Private login method for REE kernel clients */

It's worth noting that this is filtered by the TEE framework, compared
to everything else which is treated opaquely.

> +#define TEE_IOCTL_LOGIN_REE_KERNEL		0x80000000

>  

>  /**

>   * struct tee_ioctl_param - parameter

> -- 

> 2.7.4

> 


Thanks,
Jens
Sumit Garg July 9, 2019, 5:56 a.m. UTC | #2
Thanks Jens for your comments.

On Mon, 8 Jul 2019 at 21:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>

> Hi Sumit,

>

> On Thu, Jun 13, 2019 at 04:00:29PM +0530, Sumit Garg wrote:

> > There are use-cases where user-space shouldn't be allowed to communicate

> > directly with a TEE device which is dedicated to provide a specific

> > service for a kernel client. So add a private login method for kernel

> > clients and disallow user-space to open-session using this login method.

> >

> > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

> > ---

> >  drivers/tee/tee_core.c   | 6 ++++++

> >  include/uapi/linux/tee.h | 2 ++

> >  2 files changed, 8 insertions(+)

> >

> > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c

> > index 0f16d9f..4581bd1 100644

> > --- a/drivers/tee/tee_core.c

> > +++ b/drivers/tee/tee_core.c

> > @@ -334,6 +334,12 @@ static int tee_ioctl_open_session(struct tee_context *ctx,

> >                       goto out;

> >       }

> >

> > +     if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {

> TEE_IOCTL_LOGIN_REE_KERNEL is defined as 0x80000000 which is in the

> range specified and implementation defined by the GP spec. I wonder if

> we shouldn't filter the entire implementation defined range instead of

> just this value.


Agree. Will rather check for entire implementation defined range:
0x80000000 - 0xFFFFFFFF.

>

> > +             pr_err("login method not allowed for user-space client\n");

> pr_debug(), if it's needed at all.

>


Ok will use pr_debug() instead.

> > +             rc = -EPERM;

> > +             goto out;

> > +     }

> > +

> >       rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);

> >       if (rc)

> >               goto out;

> > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h

> > index 4b9eb06..f33c69c 100644

> > --- a/include/uapi/linux/tee.h

> > +++ b/include/uapi/linux/tee.h

> > @@ -172,6 +172,8 @@ struct tee_ioctl_buf_data {

> >  #define TEE_IOCTL_LOGIN_APPLICATION          4

> >  #define TEE_IOCTL_LOGIN_USER_APPLICATION     5

> >  #define TEE_IOCTL_LOGIN_GROUP_APPLICATION    6

> > +/* Private login method for REE kernel clients */

> It's worth noting that this is filtered by the TEE framework, compared

> to everything else which is treated opaquely.

>


IIUC, you are referring to login filter in optee_os. Change to prevent
filter for this login method is part of this PR [1].

[1] https://github.com/OP-TEE/optee_os/pull/3082

-Sumit

> > +#define TEE_IOCTL_LOGIN_REE_KERNEL           0x80000000

> >

> >  /**

> >   * struct tee_ioctl_param - parameter

> > --

> > 2.7.4

> >

>

> Thanks,

> Jens
Jens Wiklander July 9, 2019, 7:03 a.m. UTC | #3
On Tue, Jul 09, 2019 at 11:26:19AM +0530, Sumit Garg wrote:
> Thanks Jens for your comments.

> 

> On Mon, 8 Jul 2019 at 21:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:

> >

> > Hi Sumit,

> >

> > On Thu, Jun 13, 2019 at 04:00:29PM +0530, Sumit Garg wrote:

> > > There are use-cases where user-space shouldn't be allowed to communicate

> > > directly with a TEE device which is dedicated to provide a specific

> > > service for a kernel client. So add a private login method for kernel

> > > clients and disallow user-space to open-session using this login method.

> > >

> > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

> > > ---

> > >  drivers/tee/tee_core.c   | 6 ++++++

> > >  include/uapi/linux/tee.h | 2 ++

> > >  2 files changed, 8 insertions(+)

> > >

> > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c

> > > index 0f16d9f..4581bd1 100644

> > > --- a/drivers/tee/tee_core.c

> > > +++ b/drivers/tee/tee_core.c

> > > @@ -334,6 +334,12 @@ static int tee_ioctl_open_session(struct tee_context *ctx,

> > >                       goto out;

> > >       }

> > >

> > > +     if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {

> > TEE_IOCTL_LOGIN_REE_KERNEL is defined as 0x80000000 which is in the

> > range specified and implementation defined by the GP spec. I wonder if

> > we shouldn't filter the entire implementation defined range instead of

> > just this value.

> 

> Agree. Will rather check for entire implementation defined range:

> 0x80000000 - 0xFFFFFFFF.

> 

> >

> > > +             pr_err("login method not allowed for user-space client\n");

> > pr_debug(), if it's needed at all.

> >

> 

> Ok will use pr_debug() instead.

> 

> > > +             rc = -EPERM;

> > > +             goto out;

> > > +     }

> > > +

> > >       rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);

> > >       if (rc)

> > >               goto out;

> > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h

> > > index 4b9eb06..f33c69c 100644

> > > --- a/include/uapi/linux/tee.h

> > > +++ b/include/uapi/linux/tee.h

> > > @@ -172,6 +172,8 @@ struct tee_ioctl_buf_data {

> > >  #define TEE_IOCTL_LOGIN_APPLICATION          4

> > >  #define TEE_IOCTL_LOGIN_USER_APPLICATION     5

> > >  #define TEE_IOCTL_LOGIN_GROUP_APPLICATION    6

> > > +/* Private login method for REE kernel clients */

> > It's worth noting that this is filtered by the TEE framework, compared

> > to everything else which is treated opaquely.

> >

> 

> IIUC, you are referring to login filter in optee_os. Change to prevent

> filter for this login method is part of this PR [1].

> 

> [1] https://github.com/OP-TEE/optee_os/pull/3082


No, I was referring to the changes in tee_ioctl_open_session() above.
It's relevant for user space to know since it will be prevented from
using that range of login identifiers. This will restrict the user space
API, but I think the risk of breakage is minimal as OP-TEE is the only
in-tree driver registering in the TEE framework. I'm not aware of any
out-of-tree drivers registering.

Thanks,
Jens

> 

> -Sumit

> 

> > > +#define TEE_IOCTL_LOGIN_REE_KERNEL           0x80000000

> > >

> > >  /**

> > >   * struct tee_ioctl_param - parameter

> > > --

> > > 2.7.4

> > >

> >

> > Thanks,

> > Jens
Sumit Garg July 9, 2019, 9:36 a.m. UTC | #4
On Tue, 9 Jul 2019 at 12:33, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>

> On Tue, Jul 09, 2019 at 11:26:19AM +0530, Sumit Garg wrote:

> > Thanks Jens for your comments.

> >

> > On Mon, 8 Jul 2019 at 21:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:

> > >

> > > Hi Sumit,

> > >

> > > On Thu, Jun 13, 2019 at 04:00:29PM +0530, Sumit Garg wrote:

> > > > There are use-cases where user-space shouldn't be allowed to communicate

> > > > directly with a TEE device which is dedicated to provide a specific

> > > > service for a kernel client. So add a private login method for kernel

> > > > clients and disallow user-space to open-session using this login method.

> > > >

> > > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

> > > > ---

> > > >  drivers/tee/tee_core.c   | 6 ++++++

> > > >  include/uapi/linux/tee.h | 2 ++

> > > >  2 files changed, 8 insertions(+)

> > > >

> > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c

> > > > index 0f16d9f..4581bd1 100644

> > > > --- a/drivers/tee/tee_core.c

> > > > +++ b/drivers/tee/tee_core.c

> > > > @@ -334,6 +334,12 @@ static int tee_ioctl_open_session(struct tee_context *ctx,

> > > >                       goto out;

> > > >       }

> > > >

> > > > +     if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {

> > > TEE_IOCTL_LOGIN_REE_KERNEL is defined as 0x80000000 which is in the

> > > range specified and implementation defined by the GP spec. I wonder if

> > > we shouldn't filter the entire implementation defined range instead of

> > > just this value.

> >

> > Agree. Will rather check for entire implementation defined range:

> > 0x80000000 - 0xFFFFFFFF.

> >


I had a second thought on this. It would be more restrictive for
user-space TEE client library which may need to use implementation
defined login method. So either we could define specific ranges for
kernel and user-space or we can start with single login method
reserved for kernel.

> > >

> > > > +             pr_err("login method not allowed for user-space client\n");

> > > pr_debug(), if it's needed at all.

> > >

> >

> > Ok will use pr_debug() instead.

> >

> > > > +             rc = -EPERM;

> > > > +             goto out;

> > > > +     }

> > > > +

> > > >       rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);

> > > >       if (rc)

> > > >               goto out;

> > > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h

> > > > index 4b9eb06..f33c69c 100644

> > > > --- a/include/uapi/linux/tee.h

> > > > +++ b/include/uapi/linux/tee.h

> > > > @@ -172,6 +172,8 @@ struct tee_ioctl_buf_data {

> > > >  #define TEE_IOCTL_LOGIN_APPLICATION          4

> > > >  #define TEE_IOCTL_LOGIN_USER_APPLICATION     5

> > > >  #define TEE_IOCTL_LOGIN_GROUP_APPLICATION    6

> > > > +/* Private login method for REE kernel clients */

> > > It's worth noting that this is filtered by the TEE framework, compared

> > > to everything else which is treated opaquely.

> > >

> >

> > IIUC, you are referring to login filter in optee_os. Change to prevent

> > filter for this login method is part of this PR [1].

> >

> > [1] https://github.com/OP-TEE/optee_os/pull/3082

>

> No, I was referring to the changes in tee_ioctl_open_session() above.

> It's relevant for user space to know since it will be prevented from

> using that range of login identifiers.


Ok, so you mean to extend the comment here for user-space to know that
this login method/range is filtered by the TEE framework. Will do
that.

> This will restrict the user space

> API, but I think the risk of breakage is minimal as OP-TEE is the only

> in-tree driver registering in the TEE framework. I'm not aware of any

> out-of-tree drivers registering.


I am not sure if I follow you here. How do you expect this change to
break out-of-tree TEE driver registration?

-Sumit

>

> Thanks,

> Jens

>

> >

> > -Sumit

> >

> > > > +#define TEE_IOCTL_LOGIN_REE_KERNEL           0x80000000

> > > >

> > > >  /**

> > > >   * struct tee_ioctl_param - parameter

> > > > --

> > > > 2.7.4

> > > >

> > >

> > > Thanks,

> > > Jens
Jens Wiklander July 29, 2019, 7:08 a.m. UTC | #5
Hi Sumit,

On Tue, Jul 9, 2019 at 11:36 AM Sumit Garg <sumit.garg@linaro.org> wrote:
>

> On Tue, 9 Jul 2019 at 12:33, Jens Wiklander <jens.wiklander@linaro.org> wrote:

> >

> > On Tue, Jul 09, 2019 at 11:26:19AM +0530, Sumit Garg wrote:

> > > Thanks Jens for your comments.

> > >

> > > On Mon, 8 Jul 2019 at 21:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:

> > > >

> > > > Hi Sumit,

> > > >

> > > > On Thu, Jun 13, 2019 at 04:00:29PM +0530, Sumit Garg wrote:

> > > > > There are use-cases where user-space shouldn't be allowed to communicate

> > > > > directly with a TEE device which is dedicated to provide a specific

> > > > > service for a kernel client. So add a private login method for kernel

> > > > > clients and disallow user-space to open-session using this login method.

> > > > >

> > > > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

> > > > > ---

> > > > >  drivers/tee/tee_core.c   | 6 ++++++

> > > > >  include/uapi/linux/tee.h | 2 ++

> > > > >  2 files changed, 8 insertions(+)

> > > > >

> > > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c

> > > > > index 0f16d9f..4581bd1 100644

> > > > > --- a/drivers/tee/tee_core.c

> > > > > +++ b/drivers/tee/tee_core.c

> > > > > @@ -334,6 +334,12 @@ static int tee_ioctl_open_session(struct tee_context *ctx,

> > > > >                       goto out;

> > > > >       }

> > > > >

> > > > > +     if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {

> > > > TEE_IOCTL_LOGIN_REE_KERNEL is defined as 0x80000000 which is in the

> > > > range specified and implementation defined by the GP spec. I wonder if

> > > > we shouldn't filter the entire implementation defined range instead of

> > > > just this value.

> > >

> > > Agree. Will rather check for entire implementation defined range:

> > > 0x80000000 - 0xFFFFFFFF.

> > >

>

> I had a second thought on this. It would be more restrictive for

> user-space TEE client library which may need to use implementation

> defined login method. So either we could define specific ranges for

> kernel and user-space or we can start with single login method

> reserved for kernel.


I think we should reserve a range for kernel internal use. Only
reserving a single single login for kernel could force us to restrict
the API once more later, better to take a chunk now and be done with
it. Half of 0x80000000 - 0xFFFFFFFF is probably more than enough too
to leave a range for user space too.

>

> > > >

> > > > > +             pr_err("login method not allowed for user-space client\n");

> > > > pr_debug(), if it's needed at all.

> > > >

> > >

> > > Ok will use pr_debug() instead.

> > >

> > > > > +             rc = -EPERM;

> > > > > +             goto out;

> > > > > +     }

> > > > > +

> > > > >       rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);

> > > > >       if (rc)

> > > > >               goto out;

> > > > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h

> > > > > index 4b9eb06..f33c69c 100644

> > > > > --- a/include/uapi/linux/tee.h

> > > > > +++ b/include/uapi/linux/tee.h

> > > > > @@ -172,6 +172,8 @@ struct tee_ioctl_buf_data {

> > > > >  #define TEE_IOCTL_LOGIN_APPLICATION          4

> > > > >  #define TEE_IOCTL_LOGIN_USER_APPLICATION     5

> > > > >  #define TEE_IOCTL_LOGIN_GROUP_APPLICATION    6

> > > > > +/* Private login method for REE kernel clients */

> > > > It's worth noting that this is filtered by the TEE framework, compared

> > > > to everything else which is treated opaquely.

> > > >

> > >

> > > IIUC, you are referring to login filter in optee_os. Change to prevent

> > > filter for this login method is part of this PR [1].

> > >

> > > [1] https://github.com/OP-TEE/optee_os/pull/3082

> >

> > No, I was referring to the changes in tee_ioctl_open_session() above.

> > It's relevant for user space to know since it will be prevented from

> > using that range of login identifiers.

>

> Ok, so you mean to extend the comment here for user-space to know that

> this login method/range is filtered by the TEE framework. Will do

> that.

>

> > This will restrict the user space

> > API, but I think the risk of breakage is minimal as OP-TEE is the only

> > in-tree driver registering in the TEE framework. I'm not aware of any

> > out-of-tree drivers registering.

>

> I am not sure if I follow you here. How do you expect this change to

> break out-of-tree TEE driver registration?


It's a change in common code that put restrictions on the API.

Thanks,
Jens


>

> -Sumit

>

> >

> > Thanks,

> > Jens

> >

> > >

> > > -Sumit

> > >

> > > > > +#define TEE_IOCTL_LOGIN_REE_KERNEL           0x80000000

> > > > >

> > > > >  /**

> > > > >   * struct tee_ioctl_param - parameter

> > > > > --

> > > > > 2.7.4

> > > > >

> > > >

> > > > Thanks,

> > > > Jens
Sumit Garg July 29, 2019, 1:13 p.m. UTC | #6
On Mon, 29 Jul 2019 at 12:39, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>

> Hi Sumit,

>

> On Tue, Jul 9, 2019 at 11:36 AM Sumit Garg <sumit.garg@linaro.org> wrote:

> >

> > On Tue, 9 Jul 2019 at 12:33, Jens Wiklander <jens.wiklander@linaro.org> wrote:

> > >

> > > On Tue, Jul 09, 2019 at 11:26:19AM +0530, Sumit Garg wrote:

> > > > Thanks Jens for your comments.

> > > >

> > > > On Mon, 8 Jul 2019 at 21:09, Jens Wiklander <jens.wiklander@linaro.org> wrote:

> > > > >

> > > > > Hi Sumit,

> > > > >

> > > > > On Thu, Jun 13, 2019 at 04:00:29PM +0530, Sumit Garg wrote:

> > > > > > There are use-cases where user-space shouldn't be allowed to communicate

> > > > > > directly with a TEE device which is dedicated to provide a specific

> > > > > > service for a kernel client. So add a private login method for kernel

> > > > > > clients and disallow user-space to open-session using this login method.

> > > > > >

> > > > > > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

> > > > > > ---

> > > > > >  drivers/tee/tee_core.c   | 6 ++++++

> > > > > >  include/uapi/linux/tee.h | 2 ++

> > > > > >  2 files changed, 8 insertions(+)

> > > > > >

> > > > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c

> > > > > > index 0f16d9f..4581bd1 100644

> > > > > > --- a/drivers/tee/tee_core.c

> > > > > > +++ b/drivers/tee/tee_core.c

> > > > > > @@ -334,6 +334,12 @@ static int tee_ioctl_open_session(struct tee_context *ctx,

> > > > > >                       goto out;

> > > > > >       }

> > > > > >

> > > > > > +     if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {

> > > > > TEE_IOCTL_LOGIN_REE_KERNEL is defined as 0x80000000 which is in the

> > > > > range specified and implementation defined by the GP spec. I wonder if

> > > > > we shouldn't filter the entire implementation defined range instead of

> > > > > just this value.

> > > >

> > > > Agree. Will rather check for entire implementation defined range:

> > > > 0x80000000 - 0xFFFFFFFF.

> > > >

> >

> > I had a second thought on this. It would be more restrictive for

> > user-space TEE client library which may need to use implementation

> > defined login method. So either we could define specific ranges for

> > kernel and user-space or we can start with single login method

> > reserved for kernel.

>

> I think we should reserve a range for kernel internal use. Only

> reserving a single single login for kernel could force us to restrict

> the API once more later, better to take a chunk now and be done with

> it. Half of 0x80000000 - 0xFFFFFFFF is probably more than enough too

> to leave a range for user space too.

>


Ok then, will rather reserve this range for kernel.

> >

> > > > >

> > > > > > +             pr_err("login method not allowed for user-space client\n");

> > > > > pr_debug(), if it's needed at all.

> > > > >

> > > >

> > > > Ok will use pr_debug() instead.

> > > >

> > > > > > +             rc = -EPERM;

> > > > > > +             goto out;

> > > > > > +     }

> > > > > > +

> > > > > >       rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);

> > > > > >       if (rc)

> > > > > >               goto out;

> > > > > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h

> > > > > > index 4b9eb06..f33c69c 100644

> > > > > > --- a/include/uapi/linux/tee.h

> > > > > > +++ b/include/uapi/linux/tee.h

> > > > > > @@ -172,6 +172,8 @@ struct tee_ioctl_buf_data {

> > > > > >  #define TEE_IOCTL_LOGIN_APPLICATION          4

> > > > > >  #define TEE_IOCTL_LOGIN_USER_APPLICATION     5

> > > > > >  #define TEE_IOCTL_LOGIN_GROUP_APPLICATION    6

> > > > > > +/* Private login method for REE kernel clients */

> > > > > It's worth noting that this is filtered by the TEE framework, compared

> > > > > to everything else which is treated opaquely.

> > > > >

> > > >

> > > > IIUC, you are referring to login filter in optee_os. Change to prevent

> > > > filter for this login method is part of this PR [1].

> > > >

> > > > [1] https://github.com/OP-TEE/optee_os/pull/3082

> > >

> > > No, I was referring to the changes in tee_ioctl_open_session() above.

> > > It's relevant for user space to know since it will be prevented from

> > > using that range of login identifiers.

> >

> > Ok, so you mean to extend the comment here for user-space to know that

> > this login method/range is filtered by the TEE framework. Will do

> > that.

> >

> > > This will restrict the user space

> > > API, but I think the risk of breakage is minimal as OP-TEE is the only

> > > in-tree driver registering in the TEE framework. I'm not aware of any

> > > out-of-tree drivers registering.

> >

> > I am not sure if I follow you here. How do you expect this change to

> > break out-of-tree TEE driver registration?

>

> It's a change in common code that put restrictions on the API.

>


Okay.

-Sumit

> Thanks,

> Jens

>

>

> >

> > -Sumit

> >

> > >

> > > Thanks,

> > > Jens

> > >

> > > >

> > > > -Sumit

> > > >

> > > > > > +#define TEE_IOCTL_LOGIN_REE_KERNEL           0x80000000

> > > > > >

> > > > > >  /**

> > > > > >   * struct tee_ioctl_param - parameter

> > > > > > --

> > > > > > 2.7.4

> > > > > >

> > > > >

> > > > > Thanks,

> > > > > Jens
diff mbox series

Patch

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 0f16d9f..4581bd1 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -334,6 +334,12 @@  static int tee_ioctl_open_session(struct tee_context *ctx,
 			goto out;
 	}
 
+	if (arg.clnt_login == TEE_IOCTL_LOGIN_REE_KERNEL) {
+		pr_err("login method not allowed for user-space client\n");
+		rc = -EPERM;
+		goto out;
+	}
+
 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
 	if (rc)
 		goto out;
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 4b9eb06..f33c69c 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -172,6 +172,8 @@  struct tee_ioctl_buf_data {
 #define TEE_IOCTL_LOGIN_APPLICATION		4
 #define TEE_IOCTL_LOGIN_USER_APPLICATION	5
 #define TEE_IOCTL_LOGIN_GROUP_APPLICATION	6
+/* Private login method for REE kernel clients */
+#define TEE_IOCTL_LOGIN_REE_KERNEL		0x80000000
 
 /**
  * struct tee_ioctl_param - parameter