[Bug 988520] Re: After failed auth, subsequent auths in same context fail

[Ubuntu Foundation's Bug Bot]

The attachment "krb5.debdiff" of this bug report has been identified as
being a patch in the form of a debdiff.  The ubuntu-sponsors team has
been subscribed to the bug report so that they can review and hopefully
sponsor the debdiff.  In the event that this is in fact not a patch you
can resolve this situation by removing the tag 'patch' from the bug
report and editing the attachment so that it is not flagged as a patch.
Additionally, if you are member of the ubuntu-sponsors team please also
unsubscribe the team from this bug report.

[This is an automated message performed by a Launchpad user owned by
Brian Murray.  Please contact him regarding any issues with the action
taken in this bug report.]

** Tags added: patch

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to krb5 in Ubuntu.
https://bugs.launchpad.net/bugs/988520

Title:
  After failed auth, subsequent auths in same context fail

Status in “krb5” package in Ubuntu:
  Triaged
Status in “krb5” package in Debian:
  Fix Released

Bug description:
  SRU Justification

  [Impact]

  If an authentication fails after preauth was requested, all subsequent
  preauth-required authentications in the same Kerberos context will
  also fail. This breaks password change when credentials have expired,
  and also breaks try_first_pass functionality in Kerberos PAM modules.

  [Development Fix]

  New upstream release. Updated in Debian. Pending sync in Ubuntu.
  Verified in Ubuntu manually.

  [Stable Fix]

  Upstream patch cherry-picked. Debdiff attached.

  [Test Case]

  testcase.sh attached.

  [Regression Potential]

  Low: one line patch for missing initialisation written by upstream.


  Original report by Russ Allbery:

  MIT Kerberos 1.10 (including pre-releases and betas) exposed a bug in
  the tracking of preauth mechanisms such that, if an authentication
  fails after preauth was requested, all subsequent preauth-required
  authentications in the same Kerberos context will also fail.

  This breaks password change when credentials have expired, and also
  breaks try_first_pass functionality in Kerberos PAM modules.

  Upstream has fixed this problem in their mainline with commit 25822.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/krb5/+bug/988520/+subscriptions