From: Ben Greear <greearb@candelatech•com>
To: Jesse Gross <jesse@nicira•com>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH 2.6.36/stable v2] vlan: Fix crash when hwaccel rx pkt for non-existant vlan.
Date: Wed, 27 Oct 2010 17:15:53 -0700 [thread overview]
Message-ID: <4CC8C0B9.6090209@candelatech.com> (raw)
In-Reply-To: <AANLkTi=EHVBSNNmsts4xTVZ2DGTBD92mHnpP0e5ZYEx1@mail.gmail.com>
On 10/27/2010 05:11 PM, Jesse Gross wrote:
> On Tue, Oct 26, 2010 at 10:06 AM, Ben Greear<greearb@candelatech•com> wrote:
>> The vlan_hwaccel_do_receive code expected skb->dev to always
>> be a vlan device, but if the NIC was promisc, and the VLAN
>> for a particular VID was not configured, then this method
>> could receive a packet where skb->dev was NOT a vlan
>> device. This caused access of bad memory and a crash.
>>
>> Signed-off-by: Ben Greear<greearb@candelatech•com>
>> ---
>> v1 -> v2: Simplify patch..no need for setting pkt-type, etc.
>>
>> :100644 100644 0eb96f7... 0687b6c... M net/8021q/vlan_core.c
>> :100644 100644 660dd41... 5dc45b9... M net/core/dev.c
>> net/8021q/vlan_core.c | 3 +++
>> net/core/dev.c | 5 +++--
>> 2 files changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
>> index 0eb96f7..0687b6c 100644
>> --- a/net/8021q/vlan_core.c
>> +++ b/net/8021q/vlan_core.c
>> @@ -43,6 +43,9 @@ int vlan_hwaccel_do_receive(struct sk_buff *skb)
>> struct net_device *dev = skb->dev;
>> struct vlan_rx_stats *rx_stats;
>>
>> + if (!is_vlan_dev(dev))
>> + return 0;
>> +
>> skb->dev = vlan_dev_info(dev)->real_dev;
>> netif_nit_deliver(skb);
>>
>
> What if we dropped any packet with a tag in skb->vlan_tci before it
> gets to the bridge hooks? That would accomplish the original goal of
> getting packets to tcpdump while preventing them from making it to
> places where they aren't expected, It will provide the same behavior
> as earlier kernels.
The VLAN code has changed a lot since I messed with it last, so
there very well may be better ways to fix this than what I came up
with. Please propose a patch if you have a suggestion.
Thanks,
Ben
--
Ben Greear <greearb@candelatech•com>
Candela Technologies Inc http://www.candelatech.com
prev parent reply other threads:[~2010-10-28 0:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-26 17:06 [PATCH 2.6.36/stable v2] vlan: Fix crash when hwaccel rx pkt for non-existant vlan Ben Greear
2010-10-28 0:11 ` Jesse Gross
2010-10-28 0:15 ` Ben Greear [this message]
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