Pure-ftpd logins timeout, cause high utilization and memory leakage

  • 7008646
  • 24-May-2011
  • 05-Jun-2013

Environment

Novell Open Enterprise Server 2 (OES 2) Linux Support Pack 2
Novell Open Enterprise Server 2 (OES 2) Linux Support Pack 3

Situation

When a user attempts to login to "Novell FTP" (LUM-enabled pure-ftpd on OES 2 SP2 or SP3), the login attempt sits for 30 to 60 seconds, then times out.  Afterwards, a pure-ftpd or nwlogin process (and sometimes others) will remain and use extra CPU or memory, as seen in "top" output.
 
This happens when the user account has an expired password and is running on "grace logins".

Resolution

There are at least 2 known issues involved.
 
- For pure-ftpd or ndsd (or any process other than nwlogin) getting stuck because of grace logins, the problem is fixed in novell-lum.  OES 2 SP3's novell-lum package does not have this problem, but for OES 2 SP2, obtain the novell-lum 2.2.0.17-0.21.3 (or later).
 
- For nwlogin processes getting stuck because of grace logins, a fix is available within pure-ftpd.  For OES 2 SP3, use the update in the SLES 10 SP4 channel, pure-ftpd 1.0.22-0.30.1.  For OES 11 SP1, the problem was fixed in novell-oes-pure-ftpd before SP1 shipped, so no update beyond SP1 is necessary for this issue.
 
As a side note, nwlogin getting stuck will only happen when /etc/pure-ftpd/pure-ftpd.conf is configured with "remote_server  yes", so if remote NCP volume navigation is not required, this can be set to "no" to avoid the problem.  Other workarounds include not allowing grace logins, or to uncheck the "limit grace logins" item on user accounts.