From ac090d9c90b087d6fb714e54b2a6dd1e6c373ed6 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Mon, 17 Jan 2022 22:16:01 +0900 Subject: [PATCH] ksmbd: fix guest connection failure with nautilus MS-SMB2 describe session sign like the following. Session.SigningRequired MUST be set to TRUE under the following conditions: - If the SMB2_NEGOTIATE_SIGNING_REQUIRED bit is set in the SecurityMode field of the client request. - If the SMB2_SESSION_FLAG_IS_GUEST bit is not set in the SessionFlags field and Session.IsAnonymous is FALSE and either Connection.ShouldSign or global RequireMessageSigning is TRUE. When trying guest account connection using nautilus, The login failure happened on session setup. ksmbd does not allow this connection when the user is a guest and the connection sign is set. Just do not set session sign instead of error response as described in the specification. And this change improves the guest connection in Nautilus. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/ksmbd/smb2pdu.c | 64 ++++++++++++++++++++++------------------------ 1 file changed, 30 insertions(+), 34 deletions(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 15f331dbe17a..1866c81c5c99 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1464,11 +1464,6 @@ static int ntlm_authenticate(struct ksmbd_work *work) } if (user_guest(sess->user)) { - if (conn->sign) { - ksmbd_debug(SMB, "Guest login not allowed when signing enabled\n"); - return -EPERM; - } - rsp->SessionFlags = SMB2_SESSION_FLAG_IS_GUEST_LE; } else { struct authenticate_message *authblob; @@ -1481,38 +1476,39 @@ static int ntlm_authenticate(struct ksmbd_work *work) ksmbd_debug(SMB, "authentication failed\n"); return -EPERM; } + } + /* + * If session state is SMB2_SESSION_VALID, We can assume + * that it is reauthentication. And the user/password + * has been verified, so return it here. + */ + if (sess->state == SMB2_SESSION_VALID) { + if (conn->binding) + goto binding_session; + return 0; + } + + if ((rsp->SessionFlags != SMB2_SESSION_FLAG_IS_GUEST_LE && + (conn->sign || server_conf.enforced_signing)) || + (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED)) + sess->sign = true; + + if (smb3_encryption_negotiated(conn) && + !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { + rc = conn->ops->generate_encryptionkey(sess); + if (rc) { + ksmbd_debug(SMB, + "SMB3 encryption key generation failed\n"); + return -EINVAL; + } + sess->enc = true; + rsp->SessionFlags = SMB2_SESSION_FLAG_ENCRYPT_DATA_LE; /* - * If session state is SMB2_SESSION_VALID, We can assume - * that it is reauthentication. And the user/password - * has been verified, so return it here. + * signing is disable if encryption is enable + * on this session */ - if (sess->state == SMB2_SESSION_VALID) { - if (conn->binding) - goto binding_session; - return 0; - } - - if ((conn->sign || server_conf.enforced_signing) || - (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED)) - sess->sign = true; - - if (smb3_encryption_negotiated(conn) && - !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { - rc = conn->ops->generate_encryptionkey(sess); - if (rc) { - ksmbd_debug(SMB, - "SMB3 encryption key generation failed\n"); - return -EINVAL; - } - sess->enc = true; - rsp->SessionFlags = SMB2_SESSION_FLAG_ENCRYPT_DATA_LE; - /* - * signing is disable if encryption is enable - * on this session - */ - sess->sign = false; - } + sess->sign = false; } binding_session: