Bug ID 426328: Updating iRule procs while in use can cause a core

Last Modified: Aug 19, 2026

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

Known Affected Versions:
11.5.1, 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, 11.6.0, 11.6.0 hf1, 11.6.0 hf2, 11.6.0 hf3, 11.6.0 hf4, 11.6.0 hf5, 11.6.0 hf6, 11.6.0 hf7, 11.6.0 hf8, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3

Fixed In:
12.0.0, 11.5.2

Opened: Jul 26, 2013

Severity: 2-Critical

Related Article: K14654

Symptoms

When updating an iRule that is in process or parked and has existing connections and uses a proc, a core can occur due to incorrect internal reference counting.

Impact

The BIG-IP system might temporarily fail to process traffic, and fail over if configured as part of a high availability (HA) pair.

Conditions

High traffic iRule that both parks and uses a proc.

Workaround

Disable listener before updating iRule. For more information, see SOL14654: Updating an iRule that uses sideband connections may cause TMM to core, available here: http://support.f5.com/kb/en-us/solutions/public/14000/600/sol14654.

Fix Information

Updating an iRule that uses sideband connections no longer causes TMM to core.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips