diff options
Diffstat (limited to 'drivers/vdpa/mlx5/net/mlx5_vnet.c')
| -rw-r--r-- | drivers/vdpa/mlx5/net/mlx5_vnet.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index f648f1c54a0f..d0f91078600e 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -1563,11 +1563,27 @@ static virtio_net_ctrl_ack handle_ctrl_mq(struct mlx5_vdpa_dev *mvdev, u8 cmd) switch (cmd) { case VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET: + /* This mq feature check aligns with pre-existing userspace + * implementation. + * + * Without it, an untrusted driver could fake a multiqueue config + * request down to a non-mq device that may cause kernel to + * panic due to uninitialized resources for extra vqs. Even with + * a well behaving guest driver, it is not expected to allow + * changing the number of vqs on a non-mq device. + */ + if (!MLX5_FEATURE(mvdev, VIRTIO_NET_F_MQ)) + break; + read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->riov, (void *)&mq, sizeof(mq)); if (read != sizeof(mq)) break; newqps = mlx5vdpa16_to_cpu(mvdev, mq.virtqueue_pairs); + if (newqps < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN || + newqps > mlx5_vdpa_max_qps(mvdev->max_vqs)) + break; + if (ndev->cur_num_vqs == 2 * newqps) { status = VIRTIO_NET_OK; break; @@ -1897,11 +1913,25 @@ static u64 mlx5_vdpa_get_device_features(struct vdpa_device *vdev) return ndev->mvdev.mlx_features; } -static int verify_min_features(struct mlx5_vdpa_dev *mvdev, u64 features) +static int verify_driver_features(struct mlx5_vdpa_dev *mvdev, u64 features) { + /* Minimum features to expect */ if (!(features & BIT_ULL(VIRTIO_F_ACCESS_PLATFORM))) return -EOPNOTSUPP; + /* Double check features combination sent down by the driver. + * Fail invalid features due to absence of the depended feature. + * + * Per VIRTIO v1.1 specification, section 5.1.3.1 Feature bit + * requirements: "VIRTIO_NET_F_MQ Requires VIRTIO_NET_F_CTRL_VQ". + * By failing the invalid features sent down by untrusted drivers, + * we're assured the assumption made upon is_index_valid() and + * is_ctrl_vq_idx() will not be compromised. + */ + if ((features & (BIT_ULL(VIRTIO_NET_F_MQ) | BIT_ULL(VIRTIO_NET_F_CTRL_VQ))) == + BIT_ULL(VIRTIO_NET_F_MQ)) + return -EINVAL; + return 0; } @@ -1977,7 +2007,7 @@ static int mlx5_vdpa_set_driver_features(struct vdpa_device *vdev, u64 features) print_features(mvdev, features, true); - err = verify_min_features(mvdev, features); + err = verify_driver_features(mvdev, features); if (err) return err; |