[PATCH 6.1 116/200] kernel/printk/index.c: fix memory leak with using debugfs_lookup()

From: Greg Kroah-Hartman
Date: Fri Mar 10 2023 - 09:10:36 EST


From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Reviewed-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
Link: https://lore.kernel.org/r/20230202151411.2308576-1-gregkh@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 c85be186a7832..a6b27526baaf6 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,
--
2.39.2