net/mlx5: fix memory region cache lookup

The Memory Region (MR) cache contains pointers to mlx5_mr.
The MR cache indexes are filled when a new MR is created. As it is
possible for MR to be created on the flight, an extra validation must be
added to avoid segmentation fault.

Fixes: b0b093845793 ("net/mlx5: use buffer address for LKEY search")
Cc: stable@dpdk.org
Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 9d98443..f92eb33 100644 (file)
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -555,7 +555,8 @@ mlx5_tx_mb2mr(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
        if (likely(txq->mp2mr[i]->start <= addr && txq->mp2mr[i]->end >= addr))
                return txq->mp2mr[i]->lkey;
        for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
-               if (unlikely(txq->mp2mr[i]->mr == NULL)) {
+               if (unlikely(txq->mp2mr[i] == NULL ||
+                   txq->mp2mr[i]->mr == NULL)) {
                        /* Unknown MP, add a new MR for it. */
                        break;
                }