Bug#295731: ssh fails to bind link-scope IPv6 addresses

[Hendrik Sattler <debian@hendrik-sattler.de>]

Package: ssh
Version: 1:3.8.1p1-8.sarge.4
Severity: important


Hi,

I try to setup IPv6 on my local network. Ping6 already works but sshd refuses
to cooperate:

# sshd -d -e
debug1: sshd version OpenSSH_3.8.1p1 Debian-8.sarge.4
debug1: private host key: #0 type 0 RSA1
debug1: read PEM private key done: type RSA
debug1: private host key: #1 type 1 RSA
debug1: read PEM private key done: type DSA
debug1: private host key: #2 type 2 DSA
debug1: Bind to port 22 on 192.168.yyy.yyy.
Server listening on 192.168.yyy.yyy port 22.
debug1: Bind to port 22 on 127.0.0.1.
Server listening on 127.0.0.1 port 22.
debug1: Bind to port 22 on fe80::2xx:xxff:fexx:xxxx.
debug1: Bind to port 22 on ::1.
Server listening on ::1 port 22.

# netstat --inet6 -l -n
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp6       0      0 :::80                   :::*                    LISTEN
tcp6       0      0 ::1:22                  :::*                    LISTEN
tcp6       0      0 ::1:953                 :::*                    LISTEN
udp6       0      0 :::1038                 :::*
raw6       0      0 :::58                   :::*                    7


# ssh -6 fe80::2xx:xxff:fexx:xxxx
ssh: connect to host fe80::2xx:xxff:fexx:xxxx port 22: Invalid argument

# ssh -6 ::1
[...]
root@::1's password:

As you can see, it has no problem with ::1 but with fe80::/64 addresses.
So what the issue? Pinging the fe80::/64 address works just fine.
Binding "::" (all local IPv6 addresses) does not work, either. Not even ::1 is
bound in this case.
There is no site local IPv6 address assigned. On another host with a site
local IPV6 address assigned from router advertisement, ssh works.

HS

-- System Information:
Debian Release: 3.1
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.10
Locale: LANG=de_DE@euro, LC_CTYPE=de_DE@euro (charmap=ISO-8859-15)

Versions of packages ssh depends on:
ii  adduser                     3.59         Add and remove users and groups
ii  debconf                     1.4.30.11    Debian configuration management sy
ii  dpkg                        1.10.26      Package maintenance system for Deb
ii  libc6                       2.3.2.ds1-20 GNU C Library: Shared libraries an
ii  libpam-modules              0.76-22      Pluggable Authentication Modules f
ii  libpam-runtime              0.76-22      Runtime support for the PAM librar
ii  libpam0g                    0.76-22      Pluggable Authentication Modules l
ii  libssl0.9.7                 0.9.7e-2     SSL shared libraries
ii  libwrap0                    7.6.dbs-6    Wietse Venema's TCP wrappers libra
ii  zlib1g                      1:1.2.2-3    compression library - runtime

-- debconf information:
  ssh/insecure_rshd:
  ssh/ssh2_keys_merged:
  ssh/user_environment_tell:
* ssh/forward_warning:
  ssh/insecure_telnetd:
  ssh/new_config: true
* ssh/use_old_init_script: true
  ssh/protocol2_only: true
  ssh/encrypted_host_key_but_no_keygen:
  ssh/run_sshd: true
  ssh/SUID_client: true
  ssh/disable_cr_auth: false