[PATCH 6.6 296/322] netfilter: nf_log: replace BUG_ON by WARN_ON_ONCE when putting logger

Greg Kroah-Hartman
2024-02-03T04:15:18Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit 259eb32971e9eb24d1777a28d82730659f50fdcb ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_log.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 8cc52d2bd31b..e16f158388bb 100644
--- 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);
--
2.43.0