--- openssh-8.4p1.orig/auth-pam.c 2020-09-27 09:25:01.000000000 +0200 +++ openssh-8.4p1/auth-pam.c 2022-03-04 13:02:23.447712697 +0100 @@ -638,10 +638,12 @@ switch (PAM_MSG_MEMBER(msg, i, msg_style)) { case PAM_ERROR_MSG: case PAM_TEXT_INFO: - if ((r = sshbuf_putf(loginmsg, "%s\n", - PAM_MSG_MEMBER(msg, i, msg))) != 0) - fatal("%s: buffer error: %s", - __func__, ssh_err(r)); + if (strlen(PAM_MSG_MEMBER(msg, i, msg)) != 0) { + if ((r = sshbuf_putf(loginmsg, "%s\n", + PAM_MSG_MEMBER(msg, i, msg))) != 0) + fatal("%s: buffer error: %s", + __func__, ssh_err(r)); + } reply[i].resp_retcode = PAM_SUCCESS; break; default: