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* [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences
@ 2018-01-10 23:15 Gustavo A. R. Silva
  2018-01-11 14:40 ` Oded Gabbay
  0 siblings, 1 reply; 3+ messages in thread
From: Gustavo A. R. Silva @ 2018-01-10 23:15 UTC (permalink / raw)
  To: Felix Kuehling, Oded Gabbay, Alex Deucher, Christian König,
	David Airlie
  Cc: dri-devel, amd-gfx, linux-kernel, Gustavo A. R. Silva

In case kfd_get_process_device_data returns null, there are some
null pointer dereferences in functions kfd_bind_processes_to_device
and kfd_unbind_processes_from_device.

Fix this by printing a WARN_ON for PDDs that aren't found and skip
them with continue statements.

Addresses-Coverity-ID: 1463794 ("Dereference null return value")
Addresses-Coverity-ID: 1463772 ("Dereference null return value")
Suggested-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
Changes in v2:
 Print a WARN_ON and skip PDDs that aren't found instead of returning
 an error.

 drivers/gpu/drm/amd/amdkfd/kfd_process.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index a22fb071..4ff5f0f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -461,7 +461,8 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev)
 	hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
 		mutex_lock(&p->mutex);
 		pdd = kfd_get_process_device_data(dev, p);
-		if (pdd->bound != PDD_BOUND_SUSPENDED) {
+
+		if (WARN_ON(!pdd) || pdd->bound != PDD_BOUND_SUSPENDED) {
 			mutex_unlock(&p->mutex);
 			continue;
 		}
@@ -501,6 +502,11 @@ void kfd_unbind_processes_from_device(struct kfd_dev *dev)
 		mutex_lock(&p->mutex);
 		pdd = kfd_get_process_device_data(dev, p);
 
+		if (WARN_ON(!pdd)) {
+			mutex_unlock(&p->mutex);
+			continue;
+		}
+
 		if (pdd->bound == PDD_BOUND)
 			pdd->bound = PDD_BOUND_SUSPENDED;
 		mutex_unlock(&p->mutex);
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences
  2018-01-10 23:15 [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences Gustavo A. R. Silva
@ 2018-01-11 14:40 ` Oded Gabbay
  2018-01-11 17:42   ` Gustavo A. R. Silva
  0 siblings, 1 reply; 3+ messages in thread
From: Oded Gabbay @ 2018-01-11 14:40 UTC (permalink / raw)
  To: Gustavo A. R. Silva
  Cc: Felix Kuehling, Alex Deucher, Christian König, David Airlie,
	Maling list - DRI developers, amd-gfx list,
	Linux-Kernel@Vger. Kernel. Org

On Thu, Jan 11, 2018 at 1:15 AM, Gustavo A. R. Silva
<garsilva@embeddedor.com> wrote:
> In case kfd_get_process_device_data returns null, there are some
> null pointer dereferences in functions kfd_bind_processes_to_device
> and kfd_unbind_processes_from_device.
>
> Fix this by printing a WARN_ON for PDDs that aren't found and skip
> them with continue statements.
>
> Addresses-Coverity-ID: 1463794 ("Dereference null return value")
> Addresses-Coverity-ID: 1463772 ("Dereference null return value")
> Suggested-by: Felix Kuehling <felix.kuehling@amd.com>
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
> Changes in v2:
>  Print a WARN_ON and skip PDDs that aren't found instead of returning
>  an error.
>
>  drivers/gpu/drm/amd/amdkfd/kfd_process.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index a22fb071..4ff5f0f 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -461,7 +461,8 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev)
>         hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
>                 mutex_lock(&p->mutex);
>                 pdd = kfd_get_process_device_data(dev, p);
> -               if (pdd->bound != PDD_BOUND_SUSPENDED) {
> +
> +               if (WARN_ON(!pdd) || pdd->bound != PDD_BOUND_SUSPENDED) {
>                         mutex_unlock(&p->mutex);
>                         continue;
>                 }
> @@ -501,6 +502,11 @@ void kfd_unbind_processes_from_device(struct kfd_dev *dev)
>                 mutex_lock(&p->mutex);
>                 pdd = kfd_get_process_device_data(dev, p);
>
> +               if (WARN_ON(!pdd)) {
> +                       mutex_unlock(&p->mutex);
> +                       continue;
> +               }
> +
>                 if (pdd->bound == PDD_BOUND)
>                         pdd->bound = PDD_BOUND_SUSPENDED;
>                 mutex_unlock(&p->mutex);
> --
> 2.7.4
>
This patch is:
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences
  2018-01-11 14:40 ` Oded Gabbay
@ 2018-01-11 17:42   ` Gustavo A. R. Silva
  0 siblings, 0 replies; 3+ messages in thread
From: Gustavo A. R. Silva @ 2018-01-11 17:42 UTC (permalink / raw)
  To: Oded Gabbay
  Cc: Felix Kuehling, Alex Deucher, Christian König, David Airlie,
	Maling list - DRI developers, amd-gfx list,
	Linux-Kernel@Vger. Kernel. Org


Quoting Oded Gabbay <oded.gabbay@gmail.com>:

> On Thu, Jan 11, 2018 at 1:15 AM, Gustavo A. R. Silva
> <garsilva@embeddedor.com> wrote:
>> In case kfd_get_process_device_data returns null, there are some
>> null pointer dereferences in functions kfd_bind_processes_to_device
>> and kfd_unbind_processes_from_device.
>>
>> Fix this by printing a WARN_ON for PDDs that aren't found and skip
>> them with continue statements.
>>
>> Addresses-Coverity-ID: 1463794 ("Dereference null return value")
>> Addresses-Coverity-ID: 1463772 ("Dereference null return value")
>> Suggested-by: Felix Kuehling <felix.kuehling@amd.com>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>> Changes in v2:
>>  Print a WARN_ON and skip PDDs that aren't found instead of returning
>>  an error.
>>
>>  drivers/gpu/drm/amd/amdkfd/kfd_process.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c  
>> b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> index a22fb071..4ff5f0f 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> @@ -461,7 +461,8 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev)
>>         hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
>>                 mutex_lock(&p->mutex);
>>                 pdd = kfd_get_process_device_data(dev, p);
>> -               if (pdd->bound != PDD_BOUND_SUSPENDED) {
>> +
>> +               if (WARN_ON(!pdd) || pdd->bound != PDD_BOUND_SUSPENDED) {
>>                         mutex_unlock(&p->mutex);
>>                         continue;
>>                 }
>> @@ -501,6 +502,11 @@ void kfd_unbind_processes_from_device(struct  
>> kfd_dev *dev)
>>                 mutex_lock(&p->mutex);
>>                 pdd = kfd_get_process_device_data(dev, p);
>>
>> +               if (WARN_ON(!pdd)) {
>> +                       mutex_unlock(&p->mutex);
>> +                       continue;
>> +               }
>> +
>>                 if (pdd->bound == PDD_BOUND)
>>                         pdd->bound = PDD_BOUND_SUSPENDED;
>>                 mutex_unlock(&p->mutex);
>> --
>> 2.7.4
>>
> This patch is:
> Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>

Thank you, Oded.
--
Gustavo

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2018-01-10 23:15 [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences Gustavo A. R. Silva
2018-01-11 14:40 ` Oded Gabbay
2018-01-11 17:42   ` Gustavo A. R. Silva

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