[PATCH 6.12 152/567] cifs: Fix memory and information leak in smb3_reconfigure()

Greg Kroah-Hartman
2026-01-06T17:22:39Z

From: Zilin Guan <zilin@seu.edu.cn>

[ Upstream commit cb6d5aa9c0f10074f1ad056c3e2278ad2cc7ec8d ]

In smb3_reconfigure(), if smb3_sync_session_ctx_passwords() fails, the
function returns immediately without freeing and erasing the newly
allocated new_password and new_password2. This causes both a memory leak
and a potential information leak.

Fix this by calling kfree_sensitive() on both password buffers before
returning in this error case.

Fixes: 0f0e357902957 ("cifs: during remount, make sure passwords are in sync")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/smb/client/fs_context.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index 17133adfe798..ee9c95811477 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -1011,6 +1011,8 @@ static int smb3_reconfigure(struct fs_context *fc)
rc = smb3_sync_session_ctx_passwords(cifs_sb, ses);
if (rc) {
mutex_unlock(&ses->session_mutex);
+ kfree_sensitive(new_password);
+ kfree_sensitive(new_password2);
return rc;
}

--
2.51.0