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 <felix.kuehling@amd.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index a22fb07..4ff5f0f 100644 (file)
--- 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);