batman-adv: Check return value of try_module_get

New operations should not be started when they need an increased module
reference counter and try_module_get failed.

This patch addresses Coverity #712284: Unchecked return value

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
index 391d4fb2026f..bd032bc4e262 100644
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -99,15 +99,17 @@ int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
 
 static int batadv_log_open(struct inode *inode, struct file *file)
 {
+        if (!try_module_get(THIS_MODULE))
+                return -EBUSY;
+
         nonseekable_open(inode, file);
         file->private_data = inode->i_private;
-        batadv_inc_module_count();
         return 0;
 }
 
 static int batadv_log_release(struct inode *inode, struct file *file)
 {
-        batadv_dec_module_count();
+        module_put(THIS_MODULE);
         return 0;
 }