vCenter Server 8.0 U3x crashes and generates a core.vpxd-worker file

Products

• VMware vCenter Server 8.0

Issue/Introduction

vCenter Server 8.0 U3 randomly crashes and becomes inaccessible. 

• core.vpxd-worker.#### gets generated
• Stack traces display session management and authorization messages
• A reboot of vCenter temporarily resolves the issue

Environment

VMware vCenter Server 8.0 U3b
VMware vCenter Server 8.0 U3d

Cause

The crashes in vCenter are primarily due to a dangling Session pointer within the Vmacore::Authorize::UserCache. When a user attempts to re-login with an invalid password while already logged in, the method UpdateSessionAuthData tries to update the expiration time for all sessions. This operation dereferences a dangling pointer, leading to a crash.

The relevant stack trace indicates that the error occurs when handling login errors and managing session authentication. The method SetAuthData replaces the existing authentication data with a DummyAuthData instance without properly closing the previous session, resulting in an invalid pointer in the cache.

Resolution

Workaround

To temporarily mitigate the crashing issue, modify the vpxd configuration file to change session management settings.

1. SSH to vCenter via root

2. Edit the following file: /etc/vmware-vpx/vpxd.cfg

3. Locate the <vpxd> section and ensure the following setting is present. If it is not present, manually enter it in.

   <authorize><sessionCanOutliveToken>true</sessionCanOutliveToken></authorize>

4. Save the changes to the configuration file.

5. Restart the vCenter service to apply the changes.

This workaround prevents the vCenter from crashing when handling authentication errors.