From b81424adf7181d816c10b1345aaa3305ab0ec304 Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Mon, 1 Jul 2024 09:14:15 -0400 Subject: [PATCH] OpenSSH: correct logic error in ObscureKeystrokeTiming Cherry-pick fix: upstream: when sending ObscureKeystrokeTiming chaff packets, we can't rely on channel_did_enqueue to tell that there is data to send. This flag indicates that the channels code enqueued a packet on _this_ ppoll() iteration, not that data was enqueued in _any_ ppoll() iteration in the timeslice. ok markus@ OpenBSD-Commit-ID: 009b74fd2769b36b5284a0188ade182f00564136 Obtained from: openssh-portable 146c420d29d0 Reviewed by: gordon Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D45823 --- crypto/openssh/clientloop.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/crypto/openssh/clientloop.c b/crypto/openssh/clientloop.c index 8ec36af94b3f..6dcd6c8535aa 100644 --- a/crypto/openssh/clientloop.c +++ b/crypto/openssh/clientloop.c @@ -608,8 +608,9 @@ obfuscate_keystroke_timing(struct ssh *ssh, struct timespec *timeout, if (timespeccmp(&now, &chaff_until, >=)) { /* Stop if there have been no keystrokes for a while */ stop_reason = "chaff time expired"; - } else if (timespeccmp(&now, &next_interval, >=)) { - /* Otherwise if we were due to send, then send chaff */ + } else if (timespeccmp(&now, &next_interval, >=) && + !ssh_packet_have_data_to_write(ssh)) { + /* If due to send but have no data, then send chaff */ if (send_chaff(ssh)) nchaff++; }