int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
		      int attr_mask, struct ib_udata *udata)
{
	struct mlx5_ib_dev *dev = to_mdev(ibqp->device);
	struct mlx5_ib_qp *qp = to_mqp(ibqp);
	struct mlx5_ib_modify_qp ucmd = {};
	enum ib_qp_type qp_type;
	enum ib_qp_state cur_state, new_state;
	size_t required_cmd_sz;
	int err = -EINVAL;
	int port;
	enum rdma_link_layer ll = IB_LINK_LAYER_UNSPECIFIED;

	if (ibqp->rwq_ind_tbl)
		return -ENOSYS;

	if (udata && udata->inlen) {
		required_cmd_sz = offsetof(typeof(ucmd), reserved) +
			sizeof(ucmd.reserved);
		if (udata->inlen < required_cmd_sz)
			return -EINVAL;

		if (udata->inlen > sizeof(ucmd) &&
		    !ib_is_udata_cleared(udata, sizeof(ucmd),
					 udata->inlen - sizeof(ucmd)))
			return -EOPNOTSUPP;

		if (ib_copy_from_udata(&ucmd, udata,
				       min(udata->inlen, sizeof(ucmd))))
			return -EFAULT;

		if (ucmd.comp_mask ||
		    memchr_inv(&ucmd.reserved, 0, sizeof(ucmd.reserved)) ||
		    memchr_inv(&ucmd.burst_info.reserved, 0,
			       sizeof(ucmd.burst_info.reserved)))
			return -EOPNOTSUPP;
	}

	if (unlikely(ibqp->qp_type == IB_QPT_GSI))
		return mlx5_ib_gsi_modify_qp(ibqp, attr, attr_mask);

	if (ibqp->qp_type == IB_QPT_DRIVER)
		qp_type = qp->qp_sub_type;
	else
		qp_type = (unlikely(ibqp->qp_type == MLX5_IB_QPT_HW_GSI)) ?
			IB_QPT_GSI : ibqp->qp_type;

	if (qp_type == MLX5_IB_QPT_DCT)
		return mlx5_ib_modify_dct(ibqp, attr, attr_mask, udata);

	mutex_lock(&qp->mutex);

	cur_state = attr_mask & IB_QP_CUR_STATE ? attr->cur_qp_state : qp->state;
	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;

	if (!(cur_state == new_state && cur_state == IB_QPS_RESET)) {
		port = attr_mask & IB_QP_PORT ? attr->port_num : qp->port;
		ll = dev->ib_dev.get_link_layer(&dev->ib_dev, port);
	}

	if (qp->flags & MLX5_IB_QP_UNDERLAY) {
		if (attr_mask & ~(IB_QP_STATE | IB_QP_CUR_STATE)) {
			mlx5_ib_dbg(dev, "invalid attr_mask 0x%x when underlay QP is used\n",
				    attr_mask);
			goto out;
		}
	} else if (qp_type != MLX5_IB_QPT_REG_UMR &&
		   qp_type != MLX5_IB_QPT_DCI &&
		   !ib_modify_qp_is_ok(cur_state, new_state, qp_type, attr_mask, ll)) {
		mlx5_ib_dbg(dev, "invalid QP state transition from %d to %d, qp_type %d, attr_mask 0x%x\n",
			    cur_state, new_state, ibqp->qp_type, attr_mask);
		goto out;
	} else if (qp_type == MLX5_IB_QPT_DCI &&
		   !modify_dci_qp_is_ok(cur_state, new_state, attr_mask)) {
		mlx5_ib_dbg(dev, "invalid QP state transition from %d to %d, qp_type %d, attr_mask 0x%x\n",
			    cur_state, new_state, qp_type, attr_mask);
		goto out;
	}

	if ((attr_mask & IB_QP_PORT) &&
	    (attr->port_num == 0 ||
	     attr->port_num > dev->num_ports)) {
		mlx5_ib_dbg(dev, "invalid port number %d. number of ports is %d\n",
			    attr->port_num, dev->num_ports);
		goto out;
	}

	if (attr_mask & IB_QP_PKEY_INDEX) {
		port = attr_mask & IB_QP_PORT ? attr->port_num : qp->port;
		if (attr->pkey_index >=
		    dev->mdev->port_caps[port - 1].pkey_table_len) {
			mlx5_ib_dbg(dev, "invalid pkey index %d\n",
				    attr->pkey_index);
			goto out;
		}
	}

	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
	    attr->max_rd_atomic >
	    (1 << MLX5_CAP_GEN(dev->mdev, log_max_ra_res_qp))) {
		mlx5_ib_dbg(dev, "invalid max_rd_atomic value %d\n",
			    attr->max_rd_atomic);
		goto out;
	}

	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
	    attr->max_dest_rd_atomic >
	    (1 << MLX5_CAP_GEN(dev->mdev, log_max_ra_req_qp))) {
		mlx5_ib_dbg(dev, "invalid max_dest_rd_atomic value %d\n",
			    attr->max_dest_rd_atomic);
		goto out;
	}

	if (cur_state == new_state && cur_state == IB_QPS_RESET) {
		err = 0;
		goto out;
	}

	err = __mlx5_ib_modify_qp(ibqp, attr, attr_mask, cur_state,
				  new_state, &ucmd);

out:
	mutex_unlock(&qp->mutex);
	return err;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.