[Bug 1690485] [NEW] openssh-server SIGSYS with 'UsePrivilegeSeparation sandbox'

[KEVIN KENNY]

Public bug reported:

The 'sshd' process gets 'authentication failure' and refuses to allow
any login.

dmesg indicates that the problem is SIGSYS on a call to 'socket'
(syscall #41, signal #31).

On a hunch, I decided to test whether the problem is related to
'seccomp' and changed /etc/ssh/sshd_config from the default

# UsePrivilegeSeparation sandbox

to the former standard value

UsePrivilegeSeparation yes

and logins started to work again.

Obviously, I'd like to have the additional protection that sandboxing
would give me.

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: openssh-server 1:7.4p1-10
ProcVersionSignature: Ubuntu 4.10.0-20.22-generic 4.10.8
Uname: Linux 4.10.0-20-generic x86_64
ApportVersion: 2.20.4-0ubuntu4
Architecture: amd64
CurrentDesktop: XFCE
Date: Fri May 12 21:06:20 2017
InstallationDate: Installed on 2017-04-08 (35 days ago)
InstallationMedia:
 
SourcePackage: openssh
UpgradeStatus: Upgraded to zesty on 2017-04-24 (19 days ago)

** Affects: openssh (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug zesty

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https://bugs.launchpad.net/bugs/1690485

Title:
  openssh-server SIGSYS with 'UsePrivilegeSeparation sandbox'

Status in openssh package in Ubuntu:
  New

Bug description:
  The 'sshd' process gets 'authentication failure' and refuses to allow
  any login.

  dmesg indicates that the problem is SIGSYS on a call to 'socket'
  (syscall #41, signal #31).

  On a hunch, I decided to test whether the problem is related to
  'seccomp' and changed /etc/ssh/sshd_config from the default

  # UsePrivilegeSeparation sandbox

  to the former standard value

  UsePrivilegeSeparation yes

  and logins started to work again.

  Obviously, I'd like to have the additional protection that sandboxing
  would give me.

  ProblemType: Bug
  DistroRelease: Ubuntu 17.04
  Package: openssh-server 1:7.4p1-10
  ProcVersionSignature: Ubuntu 4.10.0-20.22-generic 4.10.8
  Uname: Linux 4.10.0-20-generic x86_64
  ApportVersion: 2.20.4-0ubuntu4
  Architecture: amd64
  CurrentDesktop: XFCE
  Date: Fri May 12 21:06:20 2017
  InstallationDate: Installed on 2017-04-08 (35 days ago)
  InstallationMedia:
   
  SourcePackage: openssh
  UpgradeStatus: Upgraded to zesty on 2017-04-24 (19 days ago)

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