Fluent Bit 4.0.3 using http plugin sink log to opensearch, randomly restart, [engine] caught signal (SIGSEGV)

[longzhihun]

Bug Report

Describe the bug

Fluentbit 4.0.3 pod restarts randomly causing caught signal (SIGSEGV)

To Reproduce

• Rubular link if applicable:
• Example log message if applicable:

Fluent Bit v4.0.3
* Copyright (C) 2015-2025 The Fluent Bit Authors
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io/

______ _                  _    ______ _ _             ___  _____ 
|  ___| |                | |   | ___ (_) |           /   ||  _  |
| |_  | |_   _  ___ _ __ | |_  | |_/ /_| |_  __   __/ /| || |/' |
|  _| | | | | |/ _ \ '_ \| __| | ___ \ | __| \ \ / / /_| ||  /| |
| |   | | |_| |  __/ | | | |_  | |_/ / | |_   \ V /\___  |\ |_/ /
\_|   |_|\__,_|\___|_| |_|\__| \____/|_|\__|   \_/     |_(_)___/ 


[2025/06/10 19:24:38] [engine] caught signal (SIGSEGV)
#0  0x55e0ba9b9988      in  prepare_destroy_conn_safe() at src/flb_upstream.c:549
#1  0x55e0ba9b9988      in  flb_upstream_conn_release() at src/flb_upstream.c:895
#2  0x55e0baaae1a4      in  http_post() at plugins/out_http/http.c:352
#3  0x55e0baaaf4f7      in  cb_http_flush() at plugins/out_http/http.c:641
#4  0x55e0bb016026      in  co_init() at lib/monkey/deps/flb_libco/amd64.c:117
#5  0xffffffffffffffff  in  ???() at ???:0

• Steps to reproduce the problem:

Start fluentbit deamonset, just waiting.

Expected behavior

Screenshots

NAME READY STATUS RESTARTS AGE fluent-bit-gq7ch 1/1 Running 1 (12h ago) 2d5h fluent-bit-sdhrf 1/1 Running 0 2d5h fluent-bit-sfm52 1/1 Running 0 29h

Your Environment

• Version used:4.0.3
• Configuration:
• Environment name and version (e.g. Kubernetes? What version?):
• Server type and version: kubernetes 1.32
• Operating System and version: x86
• Filters and plugins: http plugin.

Additional context

[edsiper]

this is being fixed here in #10466