From: David Riley <davidriley@xxxxxxxxxxxx>
virtio_gpu_get_caps_ioctl could return success with invalid data if a
second caller to the function occurred after the entry was created in
virtio_gpu_cmd_get_capset but prior to the virtio_gpu_cmd_capset_cb
callback being called. This could leak contents of memory as well
since the caps_cache allocation is done without zeroing.
Signed-off-by: David Riley <davidriley@xxxxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 949a264985fc..88c1ed57a3c5 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -526,7 +526,6 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
list_for_each_entry(cache_ent, &vgdev->cap_cache, head) {
if (cache_ent->id == args->cap_set_id &&
cache_ent->version == args->cap_set_ver) {
- ptr = cache_ent->caps_cache;
spin_unlock(&vgdev->display_info_lock);
goto copy_exit;
}
@@ -537,6 +536,7 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
virtio_gpu_cmd_get_capset(vgdev, found_valid, args->cap_set_ver,
&cache_ent);
+copy_exit:
ret = wait_event_timeout(vgdev->resp_wq,
atomic_read(&cache_ent->is_valid), 5 * HZ);
if (!ret)
@@ -544,7 +544,6 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev,
ptr = cache_ent->caps_cache;
-copy_exit:
if (copy_to_user((void __user *)(unsigned long)args->addr, ptr, size))
return -EFAULT;
--
2.22.0.rc1.311.g5d7573a151-goog
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