diff --git a/drivers/gpu/nvgpu/gk20a/as_gk20a.c b/drivers/gpu/nvgpu/gk20a/as_gk20a.c
index 1d604b83e..42fa21678 100644
--- a/drivers/gpu/nvgpu/gk20a/as_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/as_gk20a.c
@@ -73,6 +73,7 @@ static int gk20a_as_alloc_share(struct gk20a_as *as,
  */
 int gk20a_as_release_share(struct gk20a_as_share *as_share)
 {
+	struct gk20a *g = as_share->vm->mm->g;
 	int err;
 
 	gk20a_dbg_fn("");
@@ -80,7 +81,10 @@ int gk20a_as_release_share(struct gk20a_as_share *as_share)
 	if (atomic_dec_return(&as_share->ref_cnt) > 0)
 		return 0;
 
+	gk20a_busy(g->dev);
 	err = gk20a_vm_release_share(as_share);
+	gk20a_idle(g->dev);
+
 	release_as_share_id(as_share->as, as_share->id);
 	kfree(as_share);
 	return err;
diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index d2174f37f..624eec94c 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -2350,14 +2350,15 @@ int gk20a_vm_free_space(struct gk20a_as_share *as_share,
 	mutex_lock(&vm->update_gmmu_lock);
 	va_node = addr_to_reservation(vm, args->offset);
 	if (va_node) {
-		struct mapped_buffer_node *buffer;
+		struct mapped_buffer_node *buffer, *n;
 
 		/* there is no need to unallocate the buffers in va. Just
 		 * convert them into normal buffers */
 
-		list_for_each_entry(buffer,
-			&va_node->va_buffers_list, va_buffers_list)
+		list_for_each_entry_safe(buffer, n,
+			&va_node->va_buffers_list, va_buffers_list) {
 			list_del_init(&buffer->va_buffers_list);
+		}
 
 		list_del(&va_node->reserved_va_list);