diff options
| author | Vivek Kasireddy <vivek.kasireddy@intel.com> | 2025-05-01 16:24:19 -0700 |
|---|---|---|
| committer | Dmitry Osipenko <dmitry.osipenko@collabora.com> | 2025-05-12 14:49:41 +0300 |
| commit | 44b6535d8acebbbdb8b8e79b22118bb3d7fa93df (patch) | |
| tree | bffe35271b9e8fa225a2a556ba580e4a5bb0f667 | |
| parent | 9b8f32002cddf792fc6657c6f084585c7af1a858 (diff) | |
drm/virtio: Fix NULL pointer deref in virtgpu_dma_buf_free_obj()
There is a chance that obj->dma_buf would be NULL by the time
virtgpu_dma_buf_free_obj() is called. This can happen for imported
prime objects, when drm_gem_object_exported_dma_buf_free() gets
called on them before drm_gem_object_free(). This is because
drm_gem_object_exported_dma_buf_free() explicitly sets
obj->dma_buf to NULL.
Therefore, fix this issue by storing the dma_buf pointer in the
virtio_gpu_object instance and using it in virtgpu_dma_buf_free_obj.
This stored pointer is guaranteed to be valid until the object is
freed as we took a reference on it in virtgpu_gem_prime_import().
Fixes: 415cb45895f4 ("drm/virtio: Use dma_buf from GEM object instance")
Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://lore.kernel.org/r/20250501232419.180337-1-vivek.kasireddy@intel.com
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_drv.h | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_prime.c | 3 |
2 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h index f17660a71a3e..f7def8b42068 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.h +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h @@ -88,6 +88,7 @@ struct virtio_gpu_object_params { struct virtio_gpu_object { struct drm_gem_shmem_object base; + struct dma_buf *dma_buf; struct sg_table *sgt; uint32_t hw_res_handle; bool dumb; diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c index 1118a0250279..722cde5e2d86 100644 --- a/drivers/gpu/drm/virtio/virtgpu_prime.c +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c @@ -206,7 +206,7 @@ static void virtgpu_dma_buf_free_obj(struct drm_gem_object *obj) struct virtio_gpu_device *vgdev = obj->dev->dev_private; if (drm_gem_is_imported(obj)) { - struct dma_buf *dmabuf = obj->dma_buf; + struct dma_buf *dmabuf = bo->dma_buf; dma_resv_lock(dmabuf->resv, NULL); virtgpu_dma_buf_unmap(bo); @@ -332,6 +332,7 @@ struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev, obj->import_attach = attach; get_dma_buf(buf); + bo->dma_buf = buf; ret = virtgpu_dma_buf_init_obj(dev, bo, attach); if (ret < 0) |