From: Marios Makassikis mmakassikis@freebox.fr
commit 5fde3c21cf33830eda7bfd006dc7f4bf07ec9fe6 upstream.
If ksmbd.mountd is configured to assign unknown users to the guest account ("map to guest = bad user" in the config), ksmbd signs the response.
This is wrong according to MS-SMB2 3.3.5.5.3: 12. If the SMB2_SESSION_FLAG_IS_GUEST bit is not set in the SessionFlags field, and Session.IsAnonymous is FALSE, the server MUST sign the final session setup response before sending it to the client, as follows: [...]
This fixes libsmb2 based applications failing to establish a session ("Wrong signature in received").
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Signed-off-by: Marios Makassikis mmakassikis@freebox.fr Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ksmbd/smb2pdu.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -8657,6 +8657,7 @@ int smb3_decrypt_req(struct ksmbd_work * bool smb3_11_final_sess_setup_resp(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; + struct ksmbd_session *sess = work->sess; struct smb2_hdr *rsp = smb2_get_msg(work->response_buf);
if (conn->dialect < SMB30_PROT_ID) @@ -8666,6 +8667,7 @@ bool smb3_11_final_sess_setup_resp(struc rsp = ksmbd_resp_buf_next(work);
if (le16_to_cpu(rsp->Command) == SMB2_SESSION_SETUP_HE && + sess->user && !user_guest(sess->user) && rsp->Status == STATUS_SUCCESS) return true; return false;