Subject: Re: [PATCH net 1/4] mpls: validate L2 via address length

From: roopa <[email-masked]>
Date: Fri, 11 Dec 2015 16:08:24 -0800

On 12/11/15, 2:51 PM, roopa wrote:
> On 12/10/15, 11:30 AM, Robert Shearman wrote:
>> If an L2 via address for an mpls nexthop is specified, the length of
>> the L2 address must match that expected by the output device,
>> otherwise it could access memory beyond the end of the via address
>> buffer in the route.
>>
>> This check was present prior to commit f8efb73c97e2 ("mpls: multipath
>> route support"), but got lost in the refactoring, so add it back,
>> applying it to all nexthops in multipath routes.
>>
>> Fixes: f8efb73c97e2 ("mpls: multipath route support")
>> Signed-off-by: Robert Shearman <[email-masked]>
>> ---
>>  net/mpls/af_mpls.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
>> index c70d750148b6..3be29cb1f658 100644
>> --- a/net/mpls/af_mpls.c
>> +++ b/net/mpls/af_mpls.c
>> @@ -534,6 +534,10 @@ static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
>>  	if (!mpls_dev_get(dev))
>>  		goto errout;
>>  
>> +	if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
>> +	    (dev->addr_len != nh->nh_via_alen))
>> +		goto errout;
>> +
>>
> Robert, seems like the right place for this check is nla_get_via ?
never mind. This looks fine.

Acked-by: Roopa Prabhu <[email-masked]>

Thanks!.