Bug ID 930561: SIGABRT from sod watchdog when IPS has large number of hyperscan matches.

Last Modified: Apr 28, 2025

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

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2

Fixed In:
16.1.0

Opened: Jul 23, 2020

Severity: 2-Critical

Symptoms

TMM restart as SOD watchdog thinks that TMM is stuck in an infinite loop while its just busy processing of the large amount of hyperscan matches.

Impact

Traffic disrupted while tmm restarts.

Conditions

Certain IPS snort rules are weak (like NULL bytes) and on certain type of network traffic, it can lead to large number of hyperscan matches and hence it may lead to SIGABRT by SOD watchdog daemon.

Workaround

Enable the following system compliance checks in IPS profile with action DROP/REJECT. max_inspection_count -> Change action "DROP" max_signature_engine_memory_chunk_size -> Change action "DROP" max_signature_engine_memory_size -> Change action "DROP" max_signature_hs_match_count -> Change action "DROP" This will ensure that IPS does not consume more than the allowed system resources and will prevent a crash.

Fix Information

Fixed a tmm crash related to IPS

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips