SSH connection never completes, hogs CPU

[Michał Sawicz]

Since upgrading to yakkety I can't use remmina, it connects over SSH and just sits there with a black screen + a blinking caret.

It also hogs a core of my cpu.

The only output from the remmina process:

 LANG=C remmina
Remmina plugin GKEYRING (type=Secret) registered.
Remmina plugin VNC (type=Protocol) registered.
Remmina plugin VNCI (type=Protocol) registered.
Remmina plugin telepathy (type=Entry) registered.
Remmina plugin XDMCP (type=Protocol) registered.
NX: detected keyboard type pc105/pl
Remmina plugin NX (type=Protocol) registered.
Remmina plugin RDP (type=Protocol) registered.
Remmina plugin RDPF (type=File) registered.
Remmina plugin RDPS (type=Preference) registered.
Remmina plugin SFTP (type=Protocol) registered.
Remmina plugin SSH (type=Protocol) registered.
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.

(remmina:20860): Gtk-WARNING **: Allocating size to GtkScrollbar 0x55eaaa8f45b0 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?

The other side connects correctly [see attached sshd.log].

Perf shows polling to be responsible for the CPU hog:

  11,94% remmina [kernel.kallsyms] [k] do_sys_poll
   5,57% remmina libssh.so.4.4.1 [.] ssh_poll_ctx_dopoll
   4,84% remmina [kernel.kallsyms] [k] tcp_poll
   3,99% remmina [vdso] [.] __vdso_clock_gettime
   3,76% remmina [kernel.kallsyms] [k] sys_poll
   3,71% remmina [kernel.kallsyms] [k] n_tty_poll
   3,47% remmina [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore
   3,45% remmina [kernel.kallsyms] [k] __fget
   3,28% remmina [kernel.kallsyms] [k] _raw_spin_lock_irqsave
   3,27% remmina [kernel.kallsyms] [k] entry_SYSCALL_64_after_swapgs
   3,18% remmina libssh.so.4.4.1 [.] ssh_select
   2,78% remmina [kernel.kallsyms] [k] __pollwait
   2,05% remmina libssh.so.4.4.1 [.] ssh_timeout_update

And also attached gdb.txt, there's a threaded stacktrace of the remmina process interrupted while in this state.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: remmina 1.1.2-3ubuntu2
ProcVersionSignature: Ubuntu 4.8.0-27.29-generic 4.8.1
Uname: Linux 4.8.0-27-generic x86_64
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Nov 11 18:10:44 2016
InstallationDate: Installed on 2016-05-06 (188 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: remmina
UpgradeStatus: No upgrade log present (probably fresh install)

[Michał Sawicz (saviq)]

Please let me know if I can do anything else to help debug.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Michał Sawicz (saviq)]

This is fixed in Remmina 1.2, FWIW:

$ sudo snap install remmina