From 818b4d086f287e0a5cc6368eb72703b68b0603d0 Mon Sep 17 00:00:00 2001 From: Sean Heelan Date: Mon, 21 Apr 2025 15:39:29 +0000 Subject: ksmbd: fix use-after-free in session logoff The sess->user object can currently be in use by another thread, for example if another connection has sent a session setup request to bind to the session being free'd. The handler for that connection could be in the smb2_sess_setup function which makes use of sess->user. Cc: stable@vger.kernel.org Signed-off-by: Sean Heelan Acked-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smb2pdu.c | 4 ---- 1 file changed, 4 deletions(-) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2244,10 +2244,6 @@ int smb2_session_logoff(struct ksmbd_wor sess->state = SMB2_SESSION_EXPIRED; up_write(&conn->session_lock); - if (sess->user) { - ksmbd_free_user(sess->user); - sess->user = NULL; - } ksmbd_all_conn_set_status(sess_id, KSMBD_SESS_NEED_SETUP); rsp->StructureSize = cpu_to_le16(4);