static int _mlx5_ib_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
		      const struct ib_recv_wr **bad_wr, bool drain)
{
	struct mlx5_ib_qp *qp = to_mqp(ibqp);
	struct mlx5_wqe_data_seg *scat;
	struct mlx5_rwqe_sig *sig;
	struct mlx5_ib_dev *dev = to_mdev(ibqp->device);
	struct mlx5_core_dev *mdev = dev->mdev;
	unsigned long flags;
	int err = 0;
	int nreq;
	int ind;
	int i;

	if (unlikely(ibqp->qp_type == IB_QPT_GSI))
		return mlx5_ib_gsi_post_recv(ibqp, wr, bad_wr);

	spin_lock_irqsave(&qp->rq.lock, flags);

	if (mdev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR && !drain) {
		err = -EIO;
		*bad_wr = wr;
		nreq = 0;
		goto out;
	}

	ind = qp->rq.head & (qp->rq.wqe_cnt - 1);

	for (nreq = 0; wr; nreq++, wr = wr->next) {
		if (mlx5_wq_overflow(&qp->rq, nreq, qp->ibqp.recv_cq)) {
			err = -ENOMEM;
			*bad_wr = wr;
			goto out;
		}

		if (unlikely(wr->num_sge > qp->rq.max_gs)) {
			err = -EINVAL;
			*bad_wr = wr;
			goto out;
		}

		scat = get_recv_wqe(qp, ind);
		if (qp->wq_sig)
			scat++;

		for (i = 0; i < wr->num_sge; i++)
			set_data_ptr_seg(scat + i, wr->sg_list + i);

		if (i < qp->rq.max_gs) {
			scat[i].byte_count = 0;
			scat[i].lkey       = cpu_to_be32(MLX5_INVALID_LKEY);
			scat[i].addr       = 0;
		}

		if (qp->wq_sig) {
			sig = (struct mlx5_rwqe_sig *)scat;
			set_sig_seg(sig, (qp->rq.max_gs + 1) << 2);
		}

		qp->rq.wrid[ind] = wr->wr_id;

		ind = (ind + 1) & (qp->rq.wqe_cnt - 1);
	}

out:
	if (likely(nreq)) {
		qp->rq.head += nreq;

		/* Make sure that descriptors are written before
		 * doorbell record.
		 */
		wmb();

		*qp->db.db = cpu_to_be32(qp->rq.head & 0xffff);
	}

	spin_unlock_irqrestore(&qp->rq.lock, flags);

	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.