diff options
| author | David Riley | 2019-06-05 16:44:20 -0700 |
|---|---|---|
| committer | Gerd Hoffmann | 2019-06-06 09:44:40 +0200 |
| commit | 7fdf478a43869bee27e1b50955830f6ebc730b67 (patch) | |
| tree | 153bfa07887ea8f1b5b73f0a6675072626b79896 | |
| parent | 50f9495efe308eb25fd921ea7c8c8143ddeeae30 (diff) | |
drm/virtio: Ensure cached capset entries are valid before copying.
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@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190605234423.11348-1-davidriley@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 8a17ef97aada..9f43b160e1bb 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -524,7 +524,6 @@ 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; } @@ -535,6 +534,7 @@ 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) @@ -542,7 +542,6 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, ptr = cache_ent->caps_cache; -copy_exit: if (copy_to_user(u64_to_user_ptr(args->addr), ptr, size)) return -EFAULT; |