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(-)

drivers/gpu/drm/amd/amdkfd/kfd_process.c +7 -2

index a22fb071..4ff5f0f 100644
@@ -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

Quoted 46 lines · 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 <[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(-)

drivers/gpu/drm/amd/amdkfd/kfd_process.c +7 -1

index a22fb071..4ff5f0f 100644
@@ -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);

Quoted 3 lines

--
2.7.4

This patch is:

Reviewed-by Oded Gabbay <[email protected]>