diff options
authorIan Wienand <iwienand@redhat.com>2016-08-03 15:44:57 +1000
committerDavid S. Miller <davem@davemloft.net>2016-08-06 00:06:11 -0400
commit5ef9f289c4e698054e5687edb54f0da3cdc9173a (patch)
parentMerge branch 'qlcnic-fixes' (diff)
OVS: Ignore negative headroom value
net_device->ndo_set_rx_headroom (introduced in 871b642adebe300be2e50aa5f65a418510f636ec) says "Setting a negtaive value reset the rx headroom to the default value". It seems that the OVS implementation in 3a927bc7cf9d0fbe8f4a8189dd5f8440228f64e7 overlooked this and sets dev->needed_headroom unconditionally. This doesn't have an immediate effect, but can mess up later LL_RESERVED_SPACE calculations, such as done in net/ipv6/mcast.c:mld_newpack. For reference, this issue was found from a skb_panic raised there after the length calculations had given the wrong result. Note the other current users of this interface (drivers/net/tun.c:tun_set_headroom and drivers/net/veth.c:veth_set_rx_headroom) are both checking this correctly thus need no modification. Thanks to Ben for some pointers from the crash dumps! Cc: Benjamin Poirier <bpoirier@suse.com> Cc: Paolo Abeni <pabeni@redhat.com> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1361414 Signed-off-by: Ian Wienand <iwienand@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 files changed, 1 insertions, 1 deletions
diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
index 434e04c3a189..95c36147a6e1 100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -140,7 +140,7 @@ internal_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats)
static void internal_set_rx_headroom(struct net_device *dev, int new_hr)
- dev->needed_headroom = new_hr;
+ dev->needed_headroom = new_hr < 0 ? 0 : new_hr;
static const struct net_device_ops internal_dev_netdev_ops = {