Bug ID 643396: Using FLOW_INIT iRule may lead to TMM memory leak or crash

Last Modified: Aug 19, 2026

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

Known Affected Versions:
12.1.0, 12.1.0 hf1, 12.1.0 hf2, 12.1.1, 12.1.1 hf1, 12.1.1 hf2, 12.1.2, 12.1.2 hf1, 12.1.2 hf2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 hf1, 13.0.0 hf2, 13.0.0 hf3, 13.0.1

Fixed In:
13.1.0

Opened: Feb 06, 2017

Severity: 2-Critical

Related Article: K34553627

Symptoms

Memory leak in TMM or even crash may be observed if using FLOW_INIT event in iRules.

Impact

TMM memory leak or crash. Traffic disrupted while tmm restarts.

Conditions

iRule triggered by FLOW_INIT event is in use. Note: The leak is difficult to observe, and the crash requires specific steps, so encountering this issue is relatively uncommon.

Workaround

None.

Fix Information

Fixed a memory leak in the FLOW_INIT iRule event.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips