netfilter: nf_log: replace BUG_ON by WARN_ON_ONCE when putting logger

Module reference is bumped for each user, this should not ever happen.

But BUG_ON check should use rcu_access_pointer() instead.

If this ever happens, do WARN_ON_ONCE() instead of BUG_ON() and
consolidate pointer check under the rcu read side lock section.

Fixes: fab4085f4e24 ("netfilter: log: nf_log_packet() as real unified interface")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 8cc52d2bd31be518df778bbe2cfaad6172d90dbc..e16f158388bbe568cddc1be5a0a6d16069897822 100644 (file)
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -193,11 +193,12 @@ void nf_logger_put(int pf, enum nf_log_type type)
                return;
        }
 
-       BUG_ON(loggers[pf][type] == NULL);
-
        rcu_read_lock();
        logger = rcu_dereference(loggers[pf][type]);
-       module_put(logger->me);
+       if (!logger)
+               WARN_ON_ONCE(1);
+       else
+               module_put(logger->me);
        rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(nf_logger_put);