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 <m...@rbox.co>
> ---

Thanks. LGTM.

Reviewed-by: John Fastabend <john.fastab...@gmail.com>

>  net/core/sock_map.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/core/sock_map.c b/net/core/sock_map.c
> index 
> 78347d7d25ef31525f8ec0a755a18e5793ad92c0..20b348b1964a10a1b0bfbe1a90a4a4cd99715b81
>  100644
> --- a/net/core/sock_map.c
> +++ b/net/core/sock_map.c
> @@ -159,6 +159,7 @@ static void sock_map_del_link(struct sock *sk,
>                               verdict_stop = true;
>                       list_del(&link->list);
>                       sk_psock_free_link(link);
> +                     break;
>               }
>       }
>       spin_unlock_bh(&psock->link_lock);
> 
> -- 
> 2.46.2
> 



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