Bug ID 507853: MCP may crash while performing a very large chunked query and CPU is highly loaded

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, 11.5.2, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 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, 11.5.4

Opened: Feb 19, 2015

Severity: 3-Major

Related Article: K17264

Symptoms

MCP crashes while performing a chunked query (such as 'tmsh show sys connection) that returns a large result if a connection to a TMM is severed (due to a zero-window timeout).

Impact

Failover (in a device cluster) or temporary outage (in a standalone system). A core file is generated that has a stack trace that includes a message similar to the following: error reading variable: Cannot access memory at address 0x1.

Conditions

CPU is highly loaded.

Workaround

None.

Fix Information

Ensured that MCP no longer crashes when performing a large chunked query and a connection to a TMM is severed.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips