[PATCH v2 4/5] smb: server: Free sensitive data in connection.c with kfree_sensitive()

[Thomas Huth <thuth@redhat.com>]

From: Thomas Huth <thuth@redhat.com>

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@redhat.com>
---
 fs/smb/server/connection.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c
index ef6f202f4024c..68b9e698b1cb6 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);
 }
@@ -671,7 +671,7 @@ static void stop_sessions(void)
 		if (atomic_dec_and_test(&target->refcnt)) {
 			ida_destroy(&target->async_ida);
 			t->ops->free_transport(t);
-			kfree(target);
+			kfree_sensitive(target);
 		}
 		goto again;
 	}
-- 
2.55.0