From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrien Mazarguil Subject: Re: [PATCH v2] net/mlx5: Fix possible NULL deref in RX path Date: Tue, 2 Aug 2016 14:32:59 +0200 Message-ID: <20160802123258.GE30580@6wind.com> References: <1470139338-7012-1-git-send-email-sagi@grimberg.me> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org To: Sagi Grimberg Return-path: Received: from mail-wm0-f51.google.com (mail-wm0-f51.google.com [74.125.82.51]) by dpdk.org (Postfix) with ESMTP id E6A123977 for ; Tue, 2 Aug 2016 14:33:03 +0200 (CEST) Received: by mail-wm0-f51.google.com with SMTP id f65so407250704wmi.0 for ; Tue, 02 Aug 2016 05:33:03 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1470139338-7012-1-git-send-email-sagi@grimberg.me> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Aug 02, 2016 at 03:02:18PM +0300, Sagi Grimberg wrote: > 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 > --- > Changes from v1: > - check pkt only once in case we failed to allocate a buffer > > 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 fce3381ae87a..37573668e43e 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) { > -- > 1.9.1 A few nit-picks from check-git-log.sh: Wrong headline uppercase: net/mlx5: Fix possible NULL deref in RX path Wrong headline lowercase: net/mlx5: Fix possible NULL deref in RX path Missing blank line after 'Fixes' tag: Fixes: a1bdb71a32da ("net/mlx5: fix crash in Rx") Otherwise, Acked-by: Adrien Mazarguil -- Adrien Mazarguil 6WIND