From 15a756b63734c1d95e3f8d922e67d11fb32b025b Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Tue, 2 Aug 2016 17:41:21 +0300 Subject: [PATCH] net/mlx5: fix possible NULL dereference in Rx path The user is allowed to call ->rx_pkt_burst() even without free mbufs in the pool. In this scenario we'll fail allocating a rep mbuf on the first iteration (where pkt is still NULL). This would cause us to deref a NULL pkt (reset refcount and free). Fix this by checking the pkt before freeing it. Fixes: a1bdb71a32da ("net/mlx5: fix crash in Rx") Signed-off-by: Sagi Grimberg Acked-by: Adrien Mazarguil --- drivers/net/mlx5/mlx5_rxtx.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c index fce3381ae8..37573668e4 100644 --- a/drivers/net/mlx5/mlx5_rxtx.c +++ b/drivers/net/mlx5/mlx5_rxtx.c @@ -1572,6 +1572,14 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n) rte_prefetch0(wqe); rep = rte_mbuf_raw_alloc(rxq->mp); if (unlikely(rep == NULL)) { + ++rxq->stats.rx_nombuf; + if (!pkt) { + /* + * no buffers before we even started, + * bail out silently. + */ + break; + } while (pkt != seg) { assert(pkt != (*rxq->elts)[idx]); seg = NEXT(pkt); @@ -1579,7 +1587,6 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n) __rte_mbuf_raw_free(pkt); pkt = seg; } - ++rxq->stats.rx_nombuf; break; } if (!pkt) { -- 2.20.1