Re: [patch net] ipv4: fix nexthop attlen check in fib_nh_match

[Jiri Pirko <jiri@resnulli.us>]

Mon, Oct 13, 2014 at 02:22:46PM CEST, eric.dumazet@gmail.com wrote:
>On Mon, 2014-10-13 at 11:54 +0200, Jiri Pirko wrote:
>> fib_nh_match does not match nexthops correctly. Example:
>> 
>> This command is not successful and route is removed. After this patch
>> applied, the route is correctly matched and result is:
>> RTNETLINK answers: No such process
>> 
>> Please consider this for stable trees as well.
>> 
>> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
>> ---
>>  net/ipv4/fib_semantics.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
>> index 5b6efb3..f99f41b 100644
>> --- a/net/ipv4/fib_semantics.c
>> +++ b/net/ipv4/fib_semantics.c
>> @@ -537,7 +537,7 @@ int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
>>  			return 1;
>>  
>>  		attrlen = rtnh_attrlen(rtnh);
>> -		if (attrlen < 0) {
>> +		if (attrlen > 0) {
>>  			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
>>  
>>  			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
>
>Fixes: 4e902c57417c4 ("[IPv4]: FIB configuration using struct fib_config")
>
>Good catch, thanks !
>
>Acked-by: Eric Dumazet <edumazet@google.com>


Thanks Eric. I reposted with your ack, fixes line and missing example.