From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: [PATCH net-next] net: systemport: Guard against unmapped TX ring Date: Fri, 20 Oct 2017 15:59:30 -0700 Message-ID: <20171020225930.11907-1-f.fainelli@gmail.com> Cc: davem@davemloft.net, Florian Fainelli To: netdev@vger.kernel.org Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:54324 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752334AbdJTW7g (ORCPT ); Fri, 20 Oct 2017 18:59:36 -0400 Received: by mail-wm0-f66.google.com with SMTP id r68so479448wmr.3 for ; Fri, 20 Oct 2017 15:59:36 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Because SYSTEMPORT is a (semi) normal network device, the stack may attempt to queue packets on it oustide of the DSA slave transmit path. When that happens, the DSA layer has not had a chance to tag packets with the appropriate per-port and per-queue information, and if that happens and we don't have a port 0 queue 0 available (e.g: on boards where this does not exist), we will hit a NULL pointer de-reference in bcm_sysport_select_queue(). Guard against such cases by testing for the TX ring validity. Fixes: 84ff33eeb23d ("net: systemport: Establish DSA network device queue mapping") Signed-off-by: Florian Fainelli --- drivers/net/ethernet/broadcom/bcmsysport.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index dafc26690555..1d9d5f986e14 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -2040,6 +2040,9 @@ static u16 bcm_sysport_select_queue(struct net_device *dev, struct sk_buff *skb, port = BRCM_TAG_GET_PORT(queue); tx_ring = priv->ring_map[q + port * priv->per_port_num_tx_queues]; + if (unlikely(!tx_ring)) + return fallback(dev, skb); + return tx_ring->index; } -- 2.9.3