[PATCH 5.15 074/136] kernel/printk/index.c: fix memory leak with using debugfs_lookup()

Greg Kroah-Hartman
2023-03-10T15:26:30Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 55bf243c514553e907efcf2bda92ba090eca8c64 ]

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>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230202151411.2308576-1-gregkh@linuxfoundation.org
Signed-off-by: Sasha Levin <sashal@kernel.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 d3709408debe9..d23b8f8a51db5 100644
--- a/kernel/printk/index.c
+++ b/kernel/printk/index.c
@@ -146,7 +146,7 @@ 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,
--
2.39.2