[ldv-project] [PATCH] drbd: add module_put() on error path in drbd_proc_open()

[Alexey Khoroshilov]

If single_open() fails in drbd_proc_open(), module refcount is left incremented.
The patch adds module_put() on the error path.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov at ispras.ru>
---
 drivers/block/drbd/drbd_proc.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c
index 56672a6..30fe0a5 100644
--- a/drivers/block/drbd/drbd_proc.c
+++ b/drivers/block/drbd/drbd_proc.c
@@ -313,8 +313,14 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
 
 static int drbd_proc_open(struct inode *inode, struct file *file)
 {
-	if (try_module_get(THIS_MODULE))
-		return single_open(file, drbd_seq_show, PDE(inode)->data);
+	int err;
+
+	if (try_module_get(THIS_MODULE)) {
+		err = single_open(file, drbd_seq_show, PDE(inode)->data);
+		if (err)
+			module_put(THIS_MODULE);
+		return err;
+	}
 	return -ENODEV;
 }
 
-- 
1.7.9.5