Bug ID 2009765: Tcpdump may crash with "malloc(): corrupted top size" when using complex BPF filters

Last Modified: Oct 19, 2025

Affected Product(s):
F5OS F5OS-A, F5OS-C(all modules)

Known Affected Versions:
F5OS-A 1.8.0

Fixed In:
F5OS-A 1.8.3

Opened: Aug 05, 2025

Severity: 3-Major

Symptoms

Running tcpdump with complex or long BPF filter expressions may result in a crash with the error message: malloc(): corrupted top size

Impact

Packet capture operations fails and no data is collected. This may impact troubleshooting or monitoring activities that rely on tcpdump.

Conditions

This issue occurs when tcpdump is invoked with a filter expression containing multiple conditions or a long filter string, especially when run via the system diagnostics

Workaround

None

Fix Information

Tcpdump has been updated to reliably support complex and long filter expressions. The utility now validates filter input to prevent errors, ensuring stable and consistent packet capture operations

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips