[Bug 523896] Re: useradd: cannot lock /etc/passwd; try again later.

[Steve Langasek]

On Sat, Aug 06, 2011 at 08:43:29AM -0000, Nicolas François wrote:
> I'm not really worried by the consistency of single files (each one are
> updated atomically).

> The problem is the inconsistency between files (e.g. /etc/passwd and
> /etc/shadow).  I'm not sure what would be the worst case if for example
> /etc/passwd is updated but /etc/shadow is not.

I think the absolute worse case would be an account locked out because
/etc/passwd has been updated with an 'x' but the corresponding entry has not
been added to /etc/shadow.  But a) that can be guarded against by changing
the files in the proper order (which is probably already being done), and b)
having lock files left behind doesn't help solve any of the resulting
problems.

Otherwise, I don't see any real possibility of breakage caused by having one
file updated without the other.

-- 
Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
Ubuntu Developer                                    http://www.debian.org/
slangasek at ubuntu.com                                     vorlon at debian.org

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to shadow in Ubuntu.
https://bugs.launchpad.net/bugs/523896

Title:
  useradd: cannot lock /etc/passwd; try again later.

Status in “shadow” package in Ubuntu:
  Confirmed

Bug description:
  Binary package hint: postfix

  Ubuntu 9.10, via Update Manager.

  SOLUTION:

  Look for /etc/group.lock, /etc/passwd.lock and /etc/shadow.lock files
  and remove them.

  Be careful to only remove the files ending in 'lock' or else you might
  damage your system.

  Please do not add comments just containing "Me too", instead please provide any information that could indicate why the files were locked:
   * the list of locked files:
      ls /etc/passwd.lock /etc/shadow.lock /etc/group.lock /etc/gshadow.lock

   * check the /var/log/auth.log for any message that could indicate the
  failure of any other tool (prior to the failure which reported the
  locked file)

   * any abnormal operation on the machine (reset, shutdown while the
  computer is still running)

  ProblemType: Package
  Architecture: i386
  Date: Thu Feb 18 09:49:47 2010
  DistroRelease: Ubuntu 9.10
  ErrorMessage: subprocess installed post-installation script returned error exit status 1
  InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
  NonfreeKernelModules: fglrx
  Package: postfix 2.6.5-3
  ProcVersionSignature: Ubuntu 2.6.31-19.56-generic
  SourcePackage: postfix
  Title: package postfix 2.6.5-3 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
  Uname: Linux 2.6.31-19-generic i686

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/523896/+subscriptions