[PATCH v2 1/2] drm/virtio: Don't attach GEM to a non-created context in gem_object_open()

From: Dmitry Osipenko
Date: Tue Apr 01 2025 - 08:39:40 EST


The vfpriv->ctx_id is always initialized to a non-zero value. Check whether
context was created before attaching GEM to this context ID. This left
unnoticed previously because host silently skips attachment if context
doesn't exist, still we shouldn't do that for consistency.

Fixes: 086b9f27f0ab ("drm/virtio: Don't create a context with default param if context_init is supported")
Cc: <stable@xxxxxxxxxxxxxxx> # v6.14+
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_gem.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 5aab588fc400..3d6aa26fdb53 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -115,13 +115,14 @@ int virtio_gpu_gem_object_open(struct drm_gem_object *obj,
if (!vgdev->has_context_init)
virtio_gpu_create_context(obj->dev, file);

- objs = virtio_gpu_array_alloc(1);
- if (!objs)
- return -ENOMEM;
- virtio_gpu_array_add_obj(objs, obj);
+ if (vfpriv->context_created) {
+ objs = virtio_gpu_array_alloc(1);
+ if (!objs)
+ return -ENOMEM;
+ virtio_gpu_array_add_obj(objs, obj);

- if (vfpriv->ctx_id)
virtio_gpu_cmd_context_attach_resource(vgdev, vfpriv->ctx_id, objs);
+ }

out_notify:
virtio_gpu_notify(vgdev);
--
2.49.0