[PATCH] kernel/fail_function: fix memory leak with using debugfs_lookup()

From: Greg Kroah-Hartman
Date: Thu Feb 02 2023 - 10:16:47 EST


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: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/fail_function.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/fail_function.c b/kernel/fail_function.c
index a7ccd2930c5f..d971a0189319 100644
--- a/kernel/fail_function.c
+++ b/kernel/fail_function.c
@@ -163,10 +163,7 @@ static void fei_debugfs_add_attr(struct fei_attr *attr)

static void fei_debugfs_remove_attr(struct fei_attr *attr)
{
- struct dentry *dir;
-
- dir = debugfs_lookup(attr->kp.symbol_name, fei_debugfs_dir);
- debugfs_remove_recursive(dir);
+ debugfs_lookup_and_remove(attr->kp.symbol_name, fei_debugfs_dir);
}

static int fei_kprobe_handler(struct kprobe *kp, struct pt_regs *regs)
--
2.39.1