From fe2c9c61f668cde28dac2b188028c5299cedcc1e Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 2 Sep 2022 15:41:11 +0200
Subject: [PATCH] net: mvpp2: debugfs: fix memory leak when using
 debugfs_lookup()

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  Fix this up to be much
simpler logic and only create the root debugfs directory once when the
driver is first accessed.  That resolves the memory leak and makes
things more obvious as to what the intent is.

Cc: Marcin Wojtas <mw@semihalf.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Cc: stable <stable@kernel.org>
Fixes: 21da57a23125 ("net: mvpp2: add a debugfs interface for the Header Parser")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
index 4a3baa7e01424..0eec05d905eb0 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c
@@ -700,10 +700,10 @@ void mvpp2_dbgfs_cleanup(struct mvpp2 *priv)
 
 void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name)
 {
-	struct dentry *mvpp2_dir, *mvpp2_root;
+	static struct dentry *mvpp2_root;
+	struct dentry *mvpp2_dir;
 	int ret, i;
 
-	mvpp2_root = debugfs_lookup(MVPP2_DRIVER_NAME, NULL);
 	if (!mvpp2_root)
 		mvpp2_root = debugfs_create_dir(MVPP2_DRIVER_NAME, NULL);
 
-- 
2.30.2