[PATCH 4/4] smb: server: Free sensitive connection data with kfree_sensitive()

[Thomas Huth]

From: Thomas Huth <thuth@xxxxxxxxxx>

struct ksmbd_conn contains an embedded struct ntlmssp_auth with the
ciphertext[] and cryptkey[] arrays, so to avoid leaking this information
via the heap, it should be freed with kfree_sensitive().

While we're at it, also use kfree_sensitive() for freeing preauth_info
in ksmbd_conn_free() to avoid that the Preauth_HashValue[] could leak
via the heap here, too.

Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
---
 fs/smb/server/connection.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c
index ef6f202f4024c..bcb688c9af918 100644
--- a/fs/smb/server/connection.c
+++ b/fs/smb/server/connection.c
@@ -117,7 +117,7 @@ static void __ksmbd_conn_release_work(struct work_struct *work)
 
 	ida_destroy(&conn->async_ida);
 	conn->transport->ops->free_transport(conn->transport);
-	kfree(conn);
+	kfree_sensitive(conn);
 }
 
 /**
@@ -183,7 +183,7 @@ void ksmbd_conn_free(struct ksmbd_conn *conn)
 	 */
 	xa_destroy(&conn->sessions);
 	kvfree(conn->request_buf);
-	kfree(conn->preauth_info);
+	kfree_sensitive(conn->preauth_info);
 	kfree(conn->mechToken);
 	ksmbd_conn_put(conn);
 }
-- 
2.55.0