Bug ID 452439: TMM may crash when enabling DOS sweep/flood if a TMM process has multiple threads

Last Modified: Oct 06, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP AFM(all modules)

Known Affected Versions:
11.5.0, 11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 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

Fixed In:
12.0.0, 11.6.1, 11.5.3 HF2, 11.5.1 HF5

Opened: Mar 14, 2014
Severity: 3-Major
Related AskF5 Article:


There is a bug caused by race condition in the library used by the AFM Sweep/flood feature. When the Sweep/flood feature is enabled, if one TMM process has multiple threads, one thread may attempt to access the memory released by another thread at some time. In this situation, TMM may crash due to access an invalid memory segment.


Traffic disrupted while tmm restarts.


(1) AFM sweep/flood enabled (2) A single TMM process has multiple threads. (3) race condition occurs


Disable thread or disable sweep/flood

Fix Information

TMM will not crash when enabling DOS sweep/flood detection feature regardless of threading.

Behavior Change