[PATCH net] mpls: fix warning with multi-label encap

[PATCH net] mpls: fix warning with multi-label encap

[George Wilkie]

If you configure a route with multiple labels, e.g.
  ip route add 10.10.3.0/24 encap mpls 16/100 via 10.10.2.2 dev ens4
A warning is logged:
  kernel: [  130.561819] netlink: 'ip': attribute type 1 has an invalid
  length.

This happens because mpls_iptunnel_policy has set the type of
MPLS_IPTUNNEL_DST to fixed size NLA_U32.
Change it to a minimum size.
nla_get_labels() does the remaining validation.

Signed-off-by: George Wilkie <gwilkie@vyatta.att-mail.com>
---
 net/mpls/mpls_iptunnel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 951b52d5835b..20c682143b01 100644
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -28,7 +28,7 @@
 #include "internal.h"
 
 static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
-	[MPLS_IPTUNNEL_DST]	= { .type = NLA_U32 },
+	[MPLS_IPTUNNEL_DST]	= { .len = sizeof(u32) },
 	[MPLS_IPTUNNEL_TTL]	= { .type = NLA_U8 },
 };
 
-- 
2.20.1

Re: [PATCH net] mpls: fix warning with multi-label encap

[David Ahern]

On 6/7/19 4:49 AM, George Wilkie wrote:
> If you configure a route with multiple labels, e.g.
>   ip route add 10.10.3.0/24 encap mpls 16/100 via 10.10.2.2 dev ens4
> A warning is logged:
>   kernel: [  130.561819] netlink: 'ip': attribute type 1 has an invalid
>   length.
> 
> This happens because mpls_iptunnel_policy has set the type of
> MPLS_IPTUNNEL_DST to fixed size NLA_U32.
> Change it to a minimum size.
> nla_get_labels() does the remaining validation.
> 
> Signed-off-by: George Wilkie <gwilkie@vyatta.att-mail.com>
> ---
>  net/mpls/mpls_iptunnel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
> index 951b52d5835b..20c682143b01 100644
> --- a/net/mpls/mpls_iptunnel.c
> +++ b/net/mpls/mpls_iptunnel.c
> @@ -28,7 +28,7 @@
>  #include "internal.h"
>  
>  static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
> -	[MPLS_IPTUNNEL_DST]	= { .type = NLA_U32 },
> +	[MPLS_IPTUNNEL_DST]	= { .len = sizeof(u32) },
>  	[MPLS_IPTUNNEL_TTL]	= { .type = NLA_U8 },
>  };
>  
> 

MPLS_IPTUNNEL_DST is an array of u32's so that looks correct

Reviewed-by: David Ahern <dsahern@gmail.com>

Re: [PATCH net] mpls: fix warning with multi-label encap

[David Ahern]

On 6/7/19 9:49 AM, David Ahern wrote:
> On 6/7/19 4:49 AM, George Wilkie wrote:
>> If you configure a route with multiple labels, e.g.
>>   ip route add 10.10.3.0/24 encap mpls 16/100 via 10.10.2.2 dev ens4
>> A warning is logged:
>>   kernel: [  130.561819] netlink: 'ip': attribute type 1 has an invalid
>>   length.
>>
>> This happens because mpls_iptunnel_policy has set the type of
>> MPLS_IPTUNNEL_DST to fixed size NLA_U32.
>> Change it to a minimum size.
>> nla_get_labels() does the remaining validation.
>>
>> Signed-off-by: George Wilkie <gwilkie@vyatta.att-mail.com>
>> ---
>>  net/mpls/mpls_iptunnel.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
>> index 951b52d5835b..20c682143b01 100644
>> --- a/net/mpls/mpls_iptunnel.c
>> +++ b/net/mpls/mpls_iptunnel.c
>> @@ -28,7 +28,7 @@
>>  #include "internal.h"
>>  
>>  static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
>> -	[MPLS_IPTUNNEL_DST]	= { .type = NLA_U32 },
>> +	[MPLS_IPTUNNEL_DST]	= { .len = sizeof(u32) },
>>  	[MPLS_IPTUNNEL_TTL]	= { .type = NLA_U8 },
>>  };
>>  
>>
> 
> MPLS_IPTUNNEL_DST is an array of u32's so that looks correct
> 
> Reviewed-by: David Ahern <dsahern@gmail.com>
> 

Fixes tag:

Fixes: e3e4712ec096 ("mpls: ip tunnel support")

Re: [PATCH net] mpls: fix warning with multi-label encap

[David Miller]

From: George Wilkie <gwilkie@vyatta.att-mail.com>
Date: Fri,  7 Jun 2019 11:49:41 +0100

> If you configure a route with multiple labels, e.g.
>   ip route add 10.10.3.0/24 encap mpls 16/100 via 10.10.2.2 dev ens4
> A warning is logged:
>   kernel: [  130.561819] netlink: 'ip': attribute type 1 has an invalid
>   length.
> 
> This happens because mpls_iptunnel_policy has set the type of
> MPLS_IPTUNNEL_DST to fixed size NLA_U32.
> Change it to a minimum size.
> nla_get_labels() does the remaining validation.
> 
> Signed-off-by: George Wilkie <gwilkie@vyatta.att-mail.com>

Applied and queued up for -stable, thanks.