Bug ID 529510: Multiple Session ha state changes may cause TMM to core

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP PEM(all modules)

Known Affected Versions:
11.5.1 HF1, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.0.0, 11.6.0 HF6

Opened: Jun 23, 2015

Severity: 3-Major


The cause of the crash is due to multiple session ha state changes in session_ha_peer_status in a very short period of time. On the active unit when the peer comes back up the session ha state changes to SESSION_HA_RESEND_NEEDED. This state change requires a call to session_ha_marker_reset to prevent the session sweeper from queueing the session ha marker when it is already in the session ha marker queue. Queueing the marker when it's already queued results in corruption of the queue which is caught by the QUEUEDEBUG_TAILQ_INSERT_TAIL macro.


Traffic disrupted while tmm restarts.


Multiple session HA state changes



Fix Information

Remove session ha maker when peer comes back up.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips