From: Namjae Jeon <linkinjeon@xxxxxxxxxx> commit 3353ab2df5f68dab7da8d5ebb427a2d265a1f2b2 upstream. This patch return STATUS_NOT_SUPPORTED if binding session is guest. Cc: stable@xxxxxxxxxxxxxxx Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-20480 Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ksmbd/smb2pdu.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1456,7 +1456,7 @@ static int ntlm_authenticate(struct ksmb * Reuse session if anonymous try to connect * on reauthetication. */ - if (ksmbd_anonymous_user(user)) { + if (conn->binding == false && ksmbd_anonymous_user(user)) { ksmbd_free_user(user); return 0; } @@ -1470,7 +1470,7 @@ static int ntlm_authenticate(struct ksmb sess->user = user; } - if (user_guest(sess->user)) { + if (conn->binding == false && user_guest(sess->user)) { rsp->SessionFlags = SMB2_SESSION_FLAG_IS_GUEST_LE; } else { struct authenticate_message *authblob; @@ -1715,6 +1715,11 @@ int smb2_sess_setup(struct ksmbd_work *w goto out_err; } + if (user_guest(sess->user)) { + rc = -EOPNOTSUPP; + goto out_err; + } + conn->binding = true; } else if ((conn->dialect < SMB30_PROT_ID || server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL) && @@ -1827,6 +1832,8 @@ out_err: rsp->hdr.Status = STATUS_NETWORK_SESSION_EXPIRED; else if (rc == -ENOMEM) rsp->hdr.Status = STATUS_INSUFFICIENT_RESOURCES; + else if (rc == -EOPNOTSUPP) + rsp->hdr.Status = STATUS_NOT_SUPPORTED; else if (rc) rsp->hdr.Status = STATUS_LOGON_FAILURE;