Re: [Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Tianyu Lan]

On 4/14/2021 11:45 PM, Greg KH wrote:

On Wed, Apr 14, 2021 at 10:49:41AM -0400, Tianyu Lan wrote:

From: Tianyu Lan 

UIO HV driver should not load in the isolation VM for security reason.
Return ENOTSUPP in the hv_uio_probe() in the isolation VM.

Signed-off-by: Tianyu Lan 
---
  drivers/uio/uio_hv_generic.c | 5 +
  1 file changed, 5 insertions(+)

diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 0330ba99730e..678b021d66f8 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -29,6 +29,7 @@
  #include 
  #include 
  #include 
+#include 
  
  #include "../hv/hyperv_vmbus.h"
  
@@ -241,6 +242,10 @@ hv_uio_probe(struct hv_device *dev,

void *ring_buffer;
int ret;
  
+	/* UIO driver should not be loaded in the isolation VM.*/

+   if (hv_is_isolation_supported())
+   return -ENOTSUPP;
+   
/* Communicating with host has to be via shared memory not hypercall */
if (!channel->offermsg.monitor_allocated) {
dev_err(&dev->device, "vmbus channel requires hypercall\n");
--
2.25.1



Again you send out known-wrong patches?

:(

Sorry for noise. Will fix this next version and I think we should make 
sure user space driver to check data from host. This patch will be removed.

Re: [Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Tianyu Lan]

Hi Stephen:
Thanks for your review.


On 4/15/2021 12:17 AM, Stephen Hemminger wrote:

On Wed, 14 Apr 2021 17:45:51 +0200
Greg KH  wrote:


On Wed, Apr 14, 2021 at 10:49:41AM -0400, Tianyu Lan wrote:

From: Tianyu Lan 

UIO HV driver should not load in the isolation VM for security reason.
Return ENOTSUPP in the hv_uio_probe() in the isolation VM.

Signed-off-by: Tianyu Lan 


This is debatable, in isolation VM's shouldn't userspace take responsibility
to validate host communication. If that is an issue please participate with
the DPDK community (main user of this) to make sure netvsc userspace driver
has the required checks.



Agree. Will report back to secure team and apply request to add change 
in userspace netvsc driver. Thanks for advise.

Re: [Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Stephen Hemminger]

On Wed, 14 Apr 2021 17:45:51 +0200
Greg KH  wrote:

> On Wed, Apr 14, 2021 at 10:49:41AM -0400, Tianyu Lan wrote:
> > From: Tianyu Lan 
> > 
> > UIO HV driver should not load in the isolation VM for security reason.
> > Return ENOTSUPP in the hv_uio_probe() in the isolation VM.
> > 
> > Signed-off-by: Tianyu Lan 

This is debatable, in isolation VM's shouldn't userspace take responsibility
to validate host communication. If that is an issue please participate with
the DPDK community (main user of this) to make sure netvsc userspace driver
has the required checks.

Re: [Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Greg KH]

On Wed, Apr 14, 2021 at 10:49:41AM -0400, Tianyu Lan wrote:
> From: Tianyu Lan 
> 
> UIO HV driver should not load in the isolation VM for security reason.
> Return ENOTSUPP in the hv_uio_probe() in the isolation VM.
> 
> Signed-off-by: Tianyu Lan 
> ---
>  drivers/uio/uio_hv_generic.c | 5 +
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
> index 0330ba99730e..678b021d66f8 100644
> --- a/drivers/uio/uio_hv_generic.c
> +++ b/drivers/uio/uio_hv_generic.c
> @@ -29,6 +29,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  
>  #include "../hv/hyperv_vmbus.h"
>  
> @@ -241,6 +242,10 @@ hv_uio_probe(struct hv_device *dev,
>   void *ring_buffer;
>   int ret;
>  
> + /* UIO driver should not be loaded in the isolation VM.*/
> + if (hv_is_isolation_supported())
> + return -ENOTSUPP;
> + 
>   /* Communicating with host has to be via shared memory not hypercall */
>   if (!channel->offermsg.monitor_allocated) {
>   dev_err(&dev->device, "vmbus channel requires hypercall\n");
> -- 
> 2.25.1
> 

Again you send out known-wrong patches?

:(

Re: [Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Christoph Hellwig]

On Wed, Apr 14, 2021 at 10:49:41AM -0400, Tianyu Lan wrote:
> From: Tianyu Lan 
> 
> UIO HV driver should not load in the isolation VM for security reason.
> Return ENOTSUPP in the hv_uio_probe() in the isolation VM.

What is the "security reason"?  After all a user can simply patch the
code and just load it anyway..

[Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.

[Tianyu Lan]

From: Tianyu Lan 

UIO HV driver should not load in the isolation VM for security reason.
Return ENOTSUPP in the hv_uio_probe() in the isolation VM.

Signed-off-by: Tianyu Lan 
---
 drivers/uio/uio_hv_generic.c | 5 +
 1 file changed, 5 insertions(+)

diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 0330ba99730e..678b021d66f8 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -29,6 +29,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include "../hv/hyperv_vmbus.h"
 
@@ -241,6 +242,10 @@ hv_uio_probe(struct hv_device *dev,
void *ring_buffer;
int ret;
 
+   /* UIO driver should not be loaded in the isolation VM.*/
+   if (hv_is_isolation_supported())
+   return -ENOTSUPP;
+   
/* Communicating with host has to be via shared memory not hypercall */
if (!channel->offermsg.monitor_allocated) {
dev_err(&dev->device, "vmbus channel requires hypercall\n");
-- 
2.25.1