Re: [PATCH net-2.6 v2] bonding: correctly process non-linear skbs

[Jay Vosburgh <fubar@us.ibm.com>]

Andy Gospodarek <andy@greyhouse.net> wrote:

>On Fri, Sep 10, 2010 at 02:04:00PM -0700, Jay Vosburgh wrote:
>> Andy Gospodarek <andy@greyhouse.net> wrote:
>> 
>> >
>> >It was recently brought to my attention that 802.3ad mode bonds would no
>> >longer form when using some network hardware after a driver update.
>> >After snooping around I realized that the particular hardware was using
>> >page-based skbs and found that skb->data did not contain a valid LACPDU
>> >as it wasn't stored there.  That explained the inability to form an
>> >802.3ad-based bond.
>> >
>> >This patch fixes the issue in my tests and should be applied to 2.6.36
>> >and as far back as anyone cares to add it to stable.
>> >
>> >Thanks to Alexander Duyck <alexander.h.duyck@intel.com> and Jesse
>> >Brandeburg <jesse.brandeburg@intel.com> for the suggestions on this one.
>> >
>> >Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
>> >CC: Alexander Duyck <alexander.h.duyck@intel.com>
>> >CC: Jesse Brandeburg <jesse.brandeburg@intel.com>
>> >CC: stable@kernel.org
>> 
>> 	Did you by any chance also test balance-alb mode?  Inspection
>> suggests that rlb_arp_recv may suffer from the same problem.
>> 
>> 	If you agree, could you add that to the patch and resubmit it?
>> 
>> 	Either way, the patch looks good.
>> 
>
>You are correct, Jay.  I did a quick test and confirmed that ARPs might
>not be properly processed when using balance-ALB too.  Below is a patch
>to fix both spots:
>
>
>[PATCH net-2.6 v2] bonding: correctly process non-linear skbs
>
>It was recently brought to my attention that 802.3ad mode bonds would no
>longer form when using some network hardware after a driver update.
>After snooping around I realized that the particular hardware was using
>page-based skbs and found that skb->data did not contain a valid LACPDU
>as it was not stored there.  That explained the inability to form an
>802.3ad-based bond.  For balance-alb mode bonds this was also an issue
>as ARPs would not be properly processed.
>
>This patch fixes the issue in my tests and should be applied to 2.6.36
>and as far back as anyone cares to add it to stable.
>
>Thanks to Alexander Duyck <alexander.h.duyck@intel.com> and Jesse
>Brandeburg <jesse.brandeburg@intel.com> for the suggestions on this one.
>
>Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
>CC: Alexander Duyck <alexander.h.duyck@intel.com>
>CC: Jesse Brandeburg <jesse.brandeburg@intel.com>
>CC: stable@kerne.org

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>


>---
> drivers/net/bonding/bond_3ad.c |    3 +++
> drivers/net/bonding/bond_alb.c |    3 +++
> 2 files changed, 6 insertions(+), 0 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
>index 822f586..0ddf4c6 100644
>--- a/drivers/net/bonding/bond_3ad.c
>+++ b/drivers/net/bonding/bond_3ad.c
>@@ -2466,6 +2466,9 @@ int bond_3ad_lacpdu_recv(struct sk_buff *skb, struct net_device *dev, struct pac
> 	if (!(dev->flags & IFF_MASTER))
> 		goto out;
>
>+	if (!pskb_may_pull(skb, sizeof(struct lacpdu)))
>+		goto out;
>+
> 	read_lock(&bond->lock);
> 	slave = bond_get_slave_by_dev((struct bonding *)netdev_priv(dev),
> 					orig_dev);
>diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
>index c746b33..26bb118 100644
>--- a/drivers/net/bonding/bond_alb.c
>+++ b/drivers/net/bonding/bond_alb.c
>@@ -362,6 +362,9 @@ static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct
> 		goto out;
> 	}
>
>+	if (!pskb_may_pull(skb, arp_hdr_len(bond_dev)))
>+		goto out;
>+
> 	if (skb->len < sizeof(struct arp_pkt)) {
> 		pr_debug("Packet is too small to be an ARP\n");
> 		goto out;
>
>-- 
>1.7.0.1
>