netfilter: log: protect nf_log_register against double registering
Currently, despite the comment right before the function,
nf_log_register allows registering two loggers on with the same type and
end up overwriting the previous register.
Not a real issue today as current tree doesn't have two loggers for the
same type but it's better to get this protected.
Also make sure that all of its callers do error checking.
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c
index 078bdca..7510198 100644
--- a/net/ipv4/netfilter/nf_log_ipv4.c
+++ b/net/ipv4/netfilter/nf_log_ipv4.c
@@ -5,6 +5,7 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/spinlock.h>
@@ -366,8 +367,17 @@
if (ret < 0)
return ret;
- nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
+ ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
+ if (ret < 0) {
+ pr_err("failed to register logger\n");
+ goto err1;
+ }
+
return 0;
+
+err1:
+ unregister_pernet_subsys(&nf_log_ipv4_net_ops);
+ return ret;
}
static void __exit nf_log_ipv4_exit(void)