From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Chris Down <chris@chrisdown.name>,
        Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        John Ogness <john.ogness@linutronix.de>
Subject: [PATCH] kernel/printk/index.c: fix memory leak with using debugfs_lookup()
Date:   Thu,  2 Feb 2023 16:14:11 +0100
Message-Id: <20230202151411.2308576-1-gregkh@linuxfoundation.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Cc: Chris Down <chris@chrisdown.name>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 kernel/printk/index.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/printk/index.c b/kernel/printk/index.c
index c85be186a783..a6b27526baaf 100644
--- a/kernel/printk/index.c
+++ b/kernel/printk/index.c
@@ -145,7 +145,7 @@ static void pi_create_file(struct module *mod)
 #ifdef CONFIG_MODULES
 static void pi_remove_file(struct module *mod)
 {
-	debugfs_remove(debugfs_lookup(pi_get_module_name(mod), dfs_index));
+	debugfs_lookup_and_remove(pi_get_module_name(mod), dfs_index);
 }
 
 static int pi_module_notify(struct notifier_block *nb, unsigned long op,
-- 
2.39.1