On 12/9/24 06:47, John Fastabend wrote:
> Michal Luczaj wrote:
>> Consider a sockmap entry being updated with the same socket:
>>
>> osk = stab->sks[idx];
>> sock_map_add_link(psock, link, map, &stab->sks[idx]);
>> stab->sks[idx] = sk;
>> if (osk)
>> sock_map_unref(osk, &stab->sks[idx]);
>>
>> Due to sock_map_unref(), which invokes sock_map_del_link(), all the psock's
>> links for stab->sks[idx] are torn:
>>
>> list_for_each_entry_safe(link, tmp, &psock->link, list) {
>> if (link->link_raw == link_raw) {
>> ...
>> list_del(&link->list);
>> sk_psock_free_link(link);
>> }
>> }
>>
>> And that includes the new link sock_map_add_link() added just before the
>> unref.
>>
>> This results in a sockmap holding a socket, but without the respective
>> link. This in turn means that close(sock) won't trigger the cleanup, i.e. a
>> closed socket will not be automatically removed from the sockmap.
>>
>> Stop tearing the links when a matching link_raw is found.
>>
>> Signed-off-by: Michal Luczaj <mhal@xxxxxxx>
>> ---
>
> Thanks. LGTM.
>
> Reviewed-by: John Fastabend <john.fastabend@xxxxxxxxx>
Thanks, and sorry for a missing tag:
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
