Bug ID 1034217: Quic_update_rtt can leave ack_delay uninitialized.

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP LTM(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, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5

Fixed In:
17.0.0, 16.1.4, 15.1.9

Opened: Jul 17, 2021

Severity: 4-Minor

Symptoms

Retransmission times become very long if there is packet loss near the beginning of the connection.

Impact

Uninitialized ack_delay variable could be any value and cause RTT measurements to be unusually large. That could cause retransmission times to be very long if there is packet loss near the beginning of the connection.

Conditions

-- Basic QUIC configuration. -- The first couple of packets in the connection reaches an uninitialized variable path before the connection reaches the ESTABLISHED state.

Workaround

N/A

Fix Information

Reusing existing ack-delay variable fixes the issue.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips