[PATCH 5.4 08/30] Revert "net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()"

From: Greg Kroah-Hartman
Date: Mon Oct 03 2022 - 03:40:46 EST

From: Sasha Levin <sashal@xxxxxxxxxx>

commit 6052a4c11fd893234e085edf7bf2e00a33a79d4e upstream.

This reverts commit fe2c9c61f668cde28dac2b188028c5299cedcc1e.

On Tue, Sep 13, 2022 at 05:48:58PM +0100, Russell King (Oracle) wrote:
>What happens if this is built as a module, and the module is loaded,
>binds (and creates the directory), then is removed, and then re-
>inserted? Nothing removes the old directory, so doesn't
>debugfs_create_dir() fail, resulting in subsequent failure to add
>any subsequent debugfs entries?
>I don't think this patch should be backported to stable trees until
>this point is addressed.

Revert until a proper fix is available as the original behavior was

Cc: Marcin Wojtas <mw@xxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: stable@xxxxxxxxxx
Reported-by: Russell King <linux@xxxxxxxxxxxxxxx>
Fixes: fe2c9c61f668 ("net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220923234736.657413-1-sashal@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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 *p

void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name)
- static struct dentry *mvpp2_root;
- struct dentry *mvpp2_dir;
+ struct dentry *mvpp2_dir, *mvpp2_root;
int ret, i;

+ mvpp2_root = debugfs_lookup(MVPP2_DRIVER_NAME, NULL);
if (!mvpp2_root)
mvpp2_root = debugfs_create_dir(MVPP2_DRIVER_NAME, NULL);