linux-kernel - [PATCH AUTOSEL 5.4 18/20] kernel/fail_function: fix memory leak with using debugfs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri,  3 Mar 2023 16:48:04 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Yang Yingliang <yangyingliang@...wei.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 5.4 18/20] kernel/fail_function: fix memory leak with using debugfs_lookup()

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

[ Upstream commit 2bb3669f576559db273efe49e0e69f82450efbca ]

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@...ux-foundation.org>
Reviewed-by: Yang Yingliang <yangyingliang@...wei.com>
Link: https://lore.kernel.org/r/20230202151633.2310897-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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 b0b1ad93fa957..8f3795d8ac5b0 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)
-- 
2.39.2