[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

A copy push command might fail, causing `migrate_to_ram` to return a
dirty HIGH_USER page to the user.

This exposes a security vulnerability in the nouveau driver. To prevent
memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
page for the destination page.

Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6fb65b01d778..097bd3af0719 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
 		goto done;
 
-	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
 	if (!dpage)
 		goto done;
 
-- 
2.34.1

[PATCH 0/2] *** BUG Fix for Nouveau Memory***

[Yonatan Maman]

This patch series addresses two critical issues in the Nouveau driver related to device channels, error handling and memory leaking.

- Memory Leak in migrate_to_ram - the migrate_to_ram function was identified as leaking memory when a copy push command fails. This results in the function returning a dirty HIGH_USER page, which can expose sensitive information and pose a security risk. To mitigate this vulnerability, the patch ensures that a zero page is allocated for the destination page, thereby preventing memory leaks and enhancing the security of the driver in case of failure.

- Privileged Error in Copy Engine Channel - an error was observed when the nouveau_dmem_copy_one function is executed, leading to a Host Copy Engine Privileged error on channel 1. The patch addresses this by adjusting the Copy Engine channel configuration to permit privileged push commands, thus resolving the error.

Yonatan Maman (2):
  nouveau/dmem: Fix privileged error in copy engine channel
  nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 drivers/gpu/drm/nouveau/nouveau_drm.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
2.34.1

[PATCH 1/2] nouveau/dmem: Fix privileged error in copy engine channel

[Yonatan Maman]

When `nouveau_dmem_copy_one` is called, the following error occurs:

[272146.675156] nouveau 0000:06:00.0: fifo: PBDMA9: 00000004 [HCE_PRIV]
ch 1 00000300 00003386

This indicates that a copy push command triggered a Host Copy Engine
Privileged error on channel 1 (Copy Engine channel). To address this
issue, modify the Copy Engine channel to allow privileged push commands

Fixes: 6de125383a5cc
Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_drm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index a58c31089613..0a75ce4c5021 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -356,7 +356,7 @@ nouveau_accel_ce_init(struct nouveau_drm *drm)
 		return;
 	}
 
-	ret = nouveau_channel_new(drm, device, false, runm, NvDmaFB, NvDmaTT, &drm->cechan);
+	ret = nouveau_channel_new(drm, device, true, runm, NvDmaFB, NvDmaTT, &drm->cechan);
 	if (ret)
 		NV_ERROR(drm, "failed to create ce channel, %d\n", ret);
 }
-- 
2.34.1

[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

A copy push command might fail, causing `migrate_to_ram` to return a
dirty HIGH_USER page to the user.

This exposes a security vulnerability in the nouveau driver. To prevent
memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
page for the destination page.

Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6fb65b01d778..097bd3af0719 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
 		goto done;
 
-	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
 	if (!dpage)
 		goto done;
 
-- 
2.34.1

[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

From: Yonatan Maman <Ymaman@Nvidia.com>

A copy push command might fail, causing `migrate_to_ram` to return a
dirty HIGH_USER page to the user.

This exposes a security vulnerability in the nouveau driver. To prevent
memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
page for the destination page.

Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6fb65b01d778..097bd3af0719 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
 		goto done;
 
-	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
 	if (!dpage)
 		goto done;
 
-- 
2.34.1

[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

From: Yonatan Maman <Ymaman@Nvidia.com>

A copy push command might fail, causing `migrate_to_ram` to return a
dirty HIGH_USER page to the user.

This exposes a security vulnerability in the nouveau driver. To prevent
memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
page for the destination page.

Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6fb65b01d778..097bd3af0719 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
 		goto done;
 
-	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
 	if (!dpage)
 		goto done;
 
-- 
2.34.1

[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

From: Yonatan Maman <Ymaman@Nvidia.com>

A copy push command might fail, causing `migrate_to_ram` to return a
dirty HIGH_USER page to the user.

This exposes a security vulnerability in the nouveau driver. To prevent
memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
page for the destination page.

Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6fb65b01d778..097bd3af0719 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
 		goto done;
 
-	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
 	if (!dpage)
 		goto done;
 
-- 
2.34.1

[PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

From: Yonatan Maman <Ymaman@Nvidia.com>

A copy push command might fail, causing `migrate_to_ram` to return a
dirty HIGH_USER page to the user.

This exposes a security vulnerability in the nouveau driver. To prevent
memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
page for the destination page.

Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6fb65b01d778..097bd3af0719 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
 	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
 		goto done;
 
-	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
+	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
 	if (!dpage)
 		goto done;
 
-- 
2.34.1

Re: [PATCH 1/2] nouveau/dmem: Fix privileged error in copy engine channel

[Danilo Krummrich]

Hi Yonatan,

On Mon, Sep 23, 2024 at 01:54:56PM +0000, Yonatan Maman wrote:
> When `nouveau_dmem_copy_one` is called, the following error occurs:
> 
> [272146.675156] nouveau 0000:06:00.0: fifo: PBDMA9: 00000004 [HCE_PRIV]
> ch 1 00000300 00003386
> 
> This indicates that a copy push command triggered a Host Copy Engine
> Privileged error on channel 1 (Copy Engine channel). To address this
> issue, modify the Copy Engine channel to allow privileged push commands
> 
> Fixes: 6de125383a5cc
> Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
> Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>

Please read [1] and use scripts/checkpatch.pl and scripts/get_maintainer.pl
before sending patches.

In particular, the 'Fixes' tag has a defined format, I recommend:

```
[core]
        abbrev = 12
[pretty]
        fixes = Fixes: %h (\"%s\")
```

in your `.gitconfig`.

Also make sure so use 'Co-developed-by' if there is a co-author; I see that this
patch is also signed off by Gal Shalom.

Please also send the patches to all relevant mailing lists and maintainers to
avoid your patches not getting the required attention.

[1] https://docs.kernel.org/process/submitting-patches.html

> ---
>  drivers/gpu/drm/nouveau/nouveau_drm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> index a58c31089613..0a75ce4c5021 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> @@ -356,7 +356,7 @@ nouveau_accel_ce_init(struct nouveau_drm *drm)
>  		return;
>  	}
>  
> -	ret = nouveau_channel_new(drm, device, false, runm, NvDmaFB, NvDmaTT, &drm->cechan);
> +	ret = nouveau_channel_new(drm, device, true, runm, NvDmaFB, NvDmaTT, &drm->cechan);
>  	if (ret)
>  		NV_ERROR(drm, "failed to create ce channel, %d\n", ret);
>  }
> -- 
> 2.34.1
> 

Re: [PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Danilo Krummrich]

On Mon, Sep 23, 2024 at 01:54:58PM +0000, Yonatan Maman wrote:
> A copy push command might fail, causing `migrate_to_ram` to return a
> dirty HIGH_USER page to the user.
> 
> This exposes a security vulnerability in the nouveau driver. To prevent
> memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
> page for the destination page.

So, you refer to the case where this function fails in nouveau_dmem_copy_one()?

If so, can you please explain why adding __GFP_ZERO to alloc_page_vma() helps
with that?

> 
> Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
> Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>

Since this is a bug, please also add a 'Fixes' tag, CC stable and add a
'Co-developed-by' tag if appropriate.

> ---
>  drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> index 6fb65b01d778..097bd3af0719 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> @@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
>  	if (!spage || !(src & MIGRATE_PFN_MIGRATE))
>  		goto done;
>  
> -	dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
> +	dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
>  	if (!dpage)
>  		goto done;
>  
> -- 
> 2.34.1
> 

Re: [PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Yonatan Maman]

On 30/09/2024 14:20, Danilo Krummrich wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Mon, Sep 23, 2024 at 01:54:58PM +0000, Yonatan Maman wrote:
>> A copy push command might fail, causing `migrate_to_ram` to return a
>> dirty HIGH_USER page to the user.
>>
>> This exposes a security vulnerability in the nouveau driver. To prevent
>> memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
>> page for the destination page.
> 
> So, you refer to the case where this function fails in nouveau_dmem_copy_one()?
> 
> If so, can you please explain why adding __GFP_ZERO to alloc_page_vma() helps
> with that?
> 

The nouveau_dmem_copy_one function ensures that the copy push command is 
sent to the device firmware but does not track whether it was executed 
successfully.

In the case of a copy error (e.g., firmware or hardware error), the 
command will be sent in the firmware channel, and nouveau_dmem_copy_one 
might succeed, as well as the migrate_to_ram function. Thus, a dirty 
page could be returned to the user.

It’s important to note that we attempted to use nouveau_fence_wait 
status to handle migration errors, but it does not catch all error types.

To avoid this vulnerability, we allocate a zero page. So that, in case 
of an error, a non-dirty (zero) page will be returned to the user.

>>
>> Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
>> Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
> 
> Since this is a bug, please also add a 'Fixes' tag, CC stable and add a
> 'Co-developed-by' tag if appropriate.

sure, thanks, I will add, and push it as V2 patch-series.
> 
>> ---
>>   drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
>> index 6fb65b01d778..097bd3af0719 100644
>> --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
>> +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
>> @@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
>>        if (!spage || !(src & MIGRATE_PFN_MIGRATE))
>>                goto done;
>>
>> -     dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
>> +     dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
>>        if (!dpage)
>>                goto done;
>>
>> --
>> 2.34.1
>>

Re: [PATCH 1/2] nouveau/dmem: Fix privileged error in copy engine channel

[Yonatan Maman]

On 30/09/2024 14:09, Danilo Krummrich wrote:
> External email: Use caution opening links or attachments
> 
> 
> Hi Yonatan,
> 
> On Mon, Sep 23, 2024 at 01:54:56PM +0000, Yonatan Maman wrote:
>> When `nouveau_dmem_copy_one` is called, the following error occurs:
>>
>> [272146.675156] nouveau 0000:06:00.0: fifo: PBDMA9: 00000004 [HCE_PRIV]
>> ch 1 00000300 00003386
>>
>> This indicates that a copy push command triggered a Host Copy Engine
>> Privileged error on channel 1 (Copy Engine channel). To address this
>> issue, modify the Copy Engine channel to allow privileged push commands
>>
>> Fixes: 6de125383a5cc
>> Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
>> Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
> 
> Please read [1] and use scripts/checkpatch.pl and scripts/get_maintainer.pl
> before sending patches.
> 
> In particular, the 'Fixes' tag has a defined format, I recommend:
> 
> ```
> [core]
>          abbrev = 12
> [pretty]
>          fixes = Fixes: %h (\"%s\")
> ```
> 
> in your `.gitconfig`.
> 
> Also make sure so use 'Co-developed-by' if there is a co-author; I see that this
> patch is also signed off by Gal Shalom.
> 
> Please also send the patches to all relevant mailing lists and maintainers to
> avoid your patches not getting the required attention.
> 
> [1] https://docs.kernel.org/process/submitting-patches.html

Thanks for the feedback! I will address these comments and send V2 
patch-set.

> 
>> ---
>>   drivers/gpu/drm/nouveau/nouveau_drm.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
>> index a58c31089613..0a75ce4c5021 100644
>> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
>> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
>> @@ -356,7 +356,7 @@ nouveau_accel_ce_init(struct nouveau_drm *drm)
>>                return;
>>        }
>>
>> -     ret = nouveau_channel_new(drm, device, false, runm, NvDmaFB, NvDmaTT, &drm->cechan);
>> +     ret = nouveau_channel_new(drm, device, true, runm, NvDmaFB, NvDmaTT, &drm->cechan);
>>        if (ret)
>>                NV_ERROR(drm, "failed to create ce channel, %d\n", ret);
>>   }
>> --
>> 2.34.1
>>

Re: [PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error

[Danilo Krummrich]

On Mon, Oct 07, 2024 at 03:28:22PM +0300, Yonatan Maman wrote:
> 
> 
> On 30/09/2024 14:20, Danilo Krummrich wrote:
> > External email: Use caution opening links or attachments
> > 
> > 
> > On Mon, Sep 23, 2024 at 01:54:58PM +0000, Yonatan Maman wrote:
> > > A copy push command might fail, causing `migrate_to_ram` to return a
> > > dirty HIGH_USER page to the user.
> > > 
> > > This exposes a security vulnerability in the nouveau driver. To prevent
> > > memory leaks in `migrate_to_ram` upon a copy error, allocate a zero
> > > page for the destination page.
> > 
> > So, you refer to the case where this function fails in nouveau_dmem_copy_one()?
> > 
> > If so, can you please explain why adding __GFP_ZERO to alloc_page_vma() helps
> > with that?
> > 
> 
> The nouveau_dmem_copy_one function ensures that the copy push command is
> sent to the device firmware but does not track whether it was executed
> successfully.
> 
> In the case of a copy error (e.g., firmware or hardware error), the command
> will be sent in the firmware channel, and nouveau_dmem_copy_one might
> succeed, as well as the migrate_to_ram function. Thus, a dirty page could be
> returned to the user.
> 
> It’s important to note that we attempted to use nouveau_fence_wait status to
> handle migration errors, but it does not catch all error types.
> 
> To avoid this vulnerability, we allocate a zero page. So that, in case of an
> error, a non-dirty (zero) page will be returned to the user.

I see, I got confused by calling this a 'memory leak'.

Please add this description in the commit message and avoid the term 'memory
leak' in this context.

> 
> > > 
> > > Signed-off-by: Yonatan Maman <Ymaman@Nvidia.com>
> > > Signed-off-by: Gal Shalom <GalShalom@Nvidia.com>
> > 
> > Since this is a bug, please also add a 'Fixes' tag, CC stable and add a
> > 'Co-developed-by' tag if appropriate.
> 
> sure, thanks, I will add, and push it as V2 patch-series.
> > 
> > > ---
> > >   drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> > > index 6fb65b01d778..097bd3af0719 100644
> > > --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
> > > +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> > > @@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf)
> > >        if (!spage || !(src & MIGRATE_PFN_MIGRATE))
> > >                goto done;
> > > 
> > > -     dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address);
> > > +     dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address);
> > >        if (!dpage)
> > >                goto done;
> > > 
> > > --
> > > 2.34.1
> > > 
>