2018-01-10 23:38:49

by Gustavo A. R. Silva

Subject: [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences

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 <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
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

2018-01-11 14:40:35

by Oded Gabbay

Subject: Re: [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences

On Thu, Jan 11, 2018 at 1:15 AM, Gustavo A. R. Silva
<[email protected]> 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 <[email protected]>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> 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 <[email protected]>

2018-01-11 17:42:48

by Gustavo A. R. Silva

Subject: Re: [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences

Quoting Oded Gabbay <[email protected]>:

> On Thu, Jan 11, 2018 at 1:15 AM, Gustavo A. R. Silva
> <[email protected]> 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 <[email protected]>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> 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 <[email protected]>

Thank you, Oded.
--
Gustavo