Re: expires larger than timeout causes error

Hi,

On 29/12/24 15:30, lilydjwg wrote:
> I have an IPv4 set with timeout 2d, but update its elements to 4d when
> a rule matches. It was fine until kernel is updated to 6.12.6 or 6.12.7.
> E.g. the following snippet gives an error when importing:
> 
> table inet blocker {
>          set spam_ips {
>                  type ipv4_addr
>                  size 65535
>                  flags dynamic,timeout
>                  timeout 2d
>                  elements = { 1.2.3.4 expires 3d }
>          }
> }
> 
> a.nft:7:16-22: Error: Could not process rule: Numerical result out of range
>                  elements = { 1.2.3.4 expires 3d }
>                               ^^^^^^^
> 

Note: I looked through the commits and this looks like a relevant commit:


commit c0f38a8c60174368aed1d0f9965d733195f15033
Author: Pablo Neira Ayuso <[email protected]>
Date:   Tue Sep 3 01:06:58 2024 +0200

     netfilter: nf_tables: reject expiration higher than timeout

     Report ERANGE to userspace if user specifies an expiration larger than
     the timeout.

     Fixes: 8e1102d5a159 ("netfilter: nf_tables: support timeouts larger 
than 23 days")
     Signed-off-by: Pablo Neira Ayuso <[email protected]>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index da75bc1de466..6c0c6f8a08a8 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6930,6 +6930,9 @@ static int nft_add_set_elem(struct nft_ctx *ctx, 
struct nft_set *set,
                                             &expiration);
                 if (err)
                         return err;
+
+               if (expiration > timeout)
+                       return -ERANGE;
         }

         if (nla[NFTA_SET_ELEM_EXPR]) {



Thanks,
Harshit

> kernel 6.10.6 worked just fine. nftables cli v1.1.1.
> 
> Despite I can't import the set, existing elements can still be updated
> to timeout more that 2d.
> 
> A new bug? Or a new limitation?
>