Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751504AbdITEM7 (ORCPT ); Wed, 20 Sep 2017 00:12:59 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:47239 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbdITEM5 (ORCPT ); Wed, 20 Sep 2017 00:12:57 -0400 X-ME-Sender: X-Sasl-enc: Hdhb5OK9ZoFUsuSYYvqLrGb0F/OtJigqxHSLpGqRB4Fi 1505880776 From: Samuel Mendoza-Jonas To: netdev@vger.kernel.org Cc: Samuel Mendoza-Jonas , "David S . Miller" , linux-kernel@vger.kernel.org Subject: [PATCH net] net/ncsi: Don't assume last available channel exists Date: Wed, 20 Sep 2017 14:12:51 +1000 Message-Id: <20170920041251.14635-1-sam@mendozajonas.com> X-Mailer: git-send-email 2.14.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1692 Lines: 53 When handling new VLAN tags in NCSI we check the maximum allowed number of filters on the last active ("hot") channel. However if the 'add' callback is called before NCSI has configured a channel, this causes a NULL dereference. Check that we actually have a hot channel, and warn if it is missing. Signed-off-by: Samuel Mendoza-Jonas --- net/ncsi/ncsi-manage.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c index 3fd3c39e6278..fc800f934beb 100644 --- a/net/ncsi/ncsi-manage.c +++ b/net/ncsi/ncsi-manage.c @@ -1420,7 +1420,10 @@ int ncsi_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid) } ndp = TO_NCSI_DEV_PRIV(nd); - ncf = ndp->hot_channel->filters[NCSI_FILTER_VLAN]; + if (!ndp) { + netdev_warn(dev, "ncsi: No ncsi_dev_priv?\n"); + return 0; + } /* Add the VLAN id to our internal list */ list_for_each_entry_rcu(vlan, &ndp->vlan_vids, list) { @@ -1432,11 +1435,17 @@ int ncsi_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid) } } - if (n_vids >= ncf->total) { - netdev_info(dev, - "NCSI Channel supports up to %u VLAN tags but %u are already set\n", - ncf->total, n_vids); - return -EINVAL; + if (!ndp->hot_channel) { + netdev_warn(dev, + "ncsi: no available filter to check maximum\n"); + } else { + ncf = ndp->hot_channel->filters[NCSI_FILTER_VLAN]; + if (n_vids >= ncf->total) { + netdev_info(dev, + "NCSI Channel supports up to %u VLAN tags but %u are already set\n", + ncf->total, n_vids); + return -EINVAL; + } } vlan = kzalloc(sizeof(*vlan), GFP_KERNEL); -- 2.14.1