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>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index a22fb0710f15..4ff5f0fe6db8 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);