linux-kernel - [PATCH 3.2 18/92] Revert "macvlan : fix checksums error when we are in bridge mode"

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: <lsq.1402104388.775889089@decadent.org.uk>
Date:	Sat, 07 Jun 2014 02:26:28 +0100
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:	akpm@...ux-foundation.org, "David S. Miller" <davem@...emloft.net>,
	"Eric Dumazet" <eric.dumazet@...il.com>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	"Patrick McHardy" <kaber@...sh.net>,
	"Daniel Lezcano" <daniel.lezcano@...e.fr>,
	"Jason Wang" <jasowang@...hat.com>,
	"Andrian Nord" <nightnord@...il.com>,
	"Vlad Yasevich" <vyasevic@...hat.com>
Subject: [PATCH 3.2 18/92] Revert "macvlan : fix checksums error when we
 are in  bridge mode"

3.2.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Vlad Yasevich <vyasevic@...hat.com>

[ Upstream commit f114890cdf84d753f6b41cd0cc44ba51d16313da ]

This reverts commit 12a2856b604476c27d85a5f9a57ae1661fc46019.
The commit above doesn't appear to be necessary any more as the
checksums appear to be correctly computed/validated.

Additionally the above commit breaks kvm configurations where
one VM is using a device that support checksum offload (virtio) and
the other VM does not.
In this case, packets leaving virtio device will have CHECKSUM_PARTIAL
set.  The packets is forwarded to a macvtap that has offload features
turned off.  Since we use CHECKSUM_UNNECESSARY, the host does does not
update the checksum and thus a bad checksum is passed up to
the guest.

CC: Daniel Lezcano <daniel.lezcano@...e.fr>
CC: Patrick McHardy <kaber@...sh.net>
CC: Andrian Nord <nightnord@...il.com>
CC: Eric Dumazet <eric.dumazet@...il.com>
CC: Michael S. Tsirkin <mst@...hat.com>
CC: Jason Wang <jasowang@...hat.com>
Signed-off-by: Vlad Yasevich <vyasevic@...hat.com>
Acked-by: Michael S. Tsirkin <mst@...hat.com>
Acked-by: Jason Wang <jasowang@...hat.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/net/macvlan.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 301b39e..ab5786b 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -236,11 +236,9 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 	const struct macvlan_dev *vlan = netdev_priv(dev);
 	const struct macvlan_port *port = vlan->port;
 	const struct macvlan_dev *dest;
-	__u8 ip_summed = skb->ip_summed;
 
 	if (vlan->mode == MACVLAN_MODE_BRIDGE) {
 		const struct ethhdr *eth = (void *)skb->data;
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
 
 		/* send to other bridge ports directly */
 		if (is_multicast_ether_addr(eth->h_dest)) {
@@ -258,7 +256,6 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 xmit_world:
-	skb->ip_summed = ip_summed;
 	skb->dev = vlan->lowerdev;
 	return dev_queue_xmit(skb);
 }

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/