Bug ID 862885: Virtual server-to-virtual server with 'Tail Loss Probe' enabled can result in 'no trailing data' error

Last Modified: Nov 23, 2020

Bug Tracker

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

Known Affected Versions:
14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 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, 16.0.0, 16.0.0.1, 16.0.1

Opened: Dec 17, 2019
Severity: 2-Critical

Symptoms

A configuration with a virtual server-to-virtual server flow established, for example by the 'virtual' iRule command, and using a TCP stack with 'Tail Loss Probe' enabled, might encounter a race between the delayed ACK and the tail loss probe, which can lead to a tmm_panic or an OOPs message: no trailing data.

Impact

TMM generates a core and reports an OOPs message: no trailing data.

Conditions

-- Virtual server-to-virtual server flow established. -- TCP profile with 'Tail Loss Probe' enabled. -- Certain timing related traffic scenario.

Workaround

Do not use a TCP stack with 'Tail Loss Probe' enabled in conjunction with a virtual server-to-virtual server flow configuration.

Fix Information

None

Behavior Change