netdev - [PATCH 4/4 net-next] ibmvnic: Handle TSO backing device errata

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1520623437-5118-5-git-send-email-tlfalcon@linux.vnet.ibm.com>
Date:   Fri,  9 Mar 2018 13:23:57 -0600
From:   Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
To:     netdev@...r.kernel.org
Cc:     nfont@...ux.vnet.ibm.com, jallen@...ux.vnet.ibm.com,
        Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
Subject: [PATCH 4/4 net-next] ibmvnic: Handle TSO backing device errata

TSO packets with one segment or with an MSS less than 224 can
cause errors on some backing devices, so disable GSO in those cases.

Signed-off-by: Thomas Falcon <tlfalcon@...ux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index d47379b95477..47377977591d 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -2052,6 +2052,23 @@ static int ibmvnic_change_mtu(struct net_device *netdev, int new_mtu)
 	return wait_for_reset(adapter);
 }
 
+static netdev_features_t ibmvnic_features_check(struct sk_buff *skb,
+						struct net_device *dev,
+						netdev_features_t features)
+{
+	/* Some backing hardware adapters can not
+	 * handle packets with a MSS less than 224
+	 * or with only one segment.
+	 */
+	if (skb_is_gso(skb)) {
+		if (skb_shinfo(skb)->gso_size < 224 ||
+		    skb_shinfo(skb)->gso_segs == 1)
+			features &= ~NETIF_F_GSO_MASK;
+	}
+
+	return features;
+}
+
 static const struct net_device_ops ibmvnic_netdev_ops = {
 	.ndo_open		= ibmvnic_open,
 	.ndo_stop		= ibmvnic_close,
@@ -2064,6 +2081,7 @@ static const struct net_device_ops ibmvnic_netdev_ops = {
 	.ndo_poll_controller	= ibmvnic_netpoll_controller,
 #endif
 	.ndo_change_mtu		= ibmvnic_change_mtu,
+	.ndo_features_check     = ibmvnic_features_check,
 };
 
 /* ethtool functions */
-- 
2.12.3