Re: aarch64 - netlink: Error: Could not process rule: No buffer space available

Steven Haigh
2026-03-04T00:49:45Z

On 4/3/26 11:42, Pablo Neira Ayuso wrote:
> On Wed, Mar 04, 2026 at 11:34:39AM +1100, Steven Haigh wrote:
>> On 4/3/26 11:17, Pablo Neira Ayuso wrote:
>>> On Wed, Mar 04, 2026 at 01:02:14AM +0100, Pablo Neira Ayuso wrote:
>>>> Hi,
>>>>
>>>> On Wed, Mar 04, 2026 at 10:36:20AM +1100, Steven Haigh wrote:
>>>>> Hi all,
>>>>>
>>>>> Firstly, please CC me in replies as I'm not subscribed to the list.
>>>>>
>>>>> I am currently loading some named sets into nftables using the following
>>>>> configuration:
>>>>>
>>>>> set au-ipv4 {
>>>>> type ipv4_addr
>>>>> flags interval
>>>>> auto-merge
>>>>> elements = { $AU.ipv4 }
>>>>> }
>>>>>
>>>>> set au-ipv6 {
>>>>> type ipv6_addr
>>>>> flags interval
>>>>> auto-merge
>>>>> elements = { $AU.ipv6 }
>>>>> }
>>>>>
>>>>> These sets are loaded in the config via:
>>>>> include "/etc/nftables/firewall/geo-nft/countrysets/AU.ipv4";
>>>>> include "/etc/nftables/firewall/geo-nft/countrysets/AU.ipv6";
>>>>>
>>>>> The files are created using the geo-nft.sh script here:
>>>>> https://raw.githubusercontent.com/wirefalls/geo-nft/main/geo-nft.sh
>>>>>
>>>>> When loading these, I get the following fatal error:
>>>>> netlink: Error: Could not process rule: No buffer space available
>>>
>>> Just to be sure and discard something simple.
>>>
>>> Maybe you made a mistake in your ruleset in the aarch64 box? With lots
>>> of errors coming from the kernel, older userspace nftables versions
>>> report ENOBUFS.
>>>
>>> Try loading AU.ipv4 and AU.ipv6 with only one element to see if
>>> userspace reports a different error.
>>>
>>> commit 47e9aaf0227daf16f43a7442e1dceae8851817a5
>>> Author: Pablo Neira Ayuso <pablo@netfilter.org>
>>> Date: Tue Aug 26 10:09:13 2025 +0200
>>> mnl: continue on ENOBUFS errors when processing batch
>>> A user reports that:
>>> nft -f ruleset.nft
>>> fails with:
>>> netlink: Error: Could not process rule: No buffer space available
>>> This was triggered by:
>>> table ip6 fule {
>>> set domestic_ip6 {
>>> type ipv6_addr
>>> flags dynamic,interval
>>> elements = $domestic_ip6
>>> }
>>> chain prerouting {
>>> type filter hook prerouting priority 0;
>>> ip6 daddr @domestic_ip6 counter
>>> }
>>> }
>>> where $domestic_ip6 contains a large number of IPv6 addresses.
>>> This set declaration is not supported currently, because dynamic sets
>>> with intervals are not supported, then every IPv6 address that is added
>>> triggers an error, overruning the userspace socket buffer with lots of
>>> NLMSG_ERROR messages (or too big NLMSG_ERROR message to fit into the
>>> socket buffer)
>>
>> --snip--
>>
>> Interesting.
>>
>> I have noticed that if I split the set into multiple 'chunks', then the set
>> can be populated properly.
>>
>> As an example, this crude claude code authored script here does function as
>> expected and the entire set is loaded successfully:
>> https://lamp.crc.id.au/paste/e0e9DD01E48E46e27F5ad1bc0e/
>
> Unfortunately, I cannot reach this link.

Apologies - its behind the firewall that I'm debugging :)

Mirrored here: https://pastebin.com/iTa9XRCb

>> It does take some time, but it does work:
>>
>> $ time ./load-countrysets.sh
>> Loaded 8480 elements into au-ipv4
>> Loaded 11577 elements into au-ipv6
>>
>> real 0m22.202s
>> user 0m20.335s
>> sys 0m1.798s
>
> Even with ASAN enabled I can load such a small ruleset a lot faster,
> not sure what this script is doing.
>

--
Steven Haigh

📧 netwiz@crc.id.au
💻 https://crc.id.au