Mutiple worker_processes cause Bad file descriptor on Alpine3.12 openresty/1.19.3.1

[yorkane]

Everything works fine under ONE nginx worker.
More than ONE nginx workers and access "redis/file/shell" will cause this issue.

Also found on alpine3.11 openresty/1.17.8.2
Environment as below:
/ # nginx -V
nginx version: openresty/1.19.3.1
built by gcc 9.3.0 (Alpine 9.3.0)
built with OpenSSL 1.1.1h 22 Sep 2020
TLS SNI support enabled
configure arguments: --prefix=/usr/local/openresty/nginx --with-cc-opt='-O2 -DNGX_LUA_ABORT_AT_PANIC -I/usr/local/openresty/zlib/include -I/usr/local/openresty/pcre/include -I/usr/local/openresty/openssl111/include' --add-module=../ngx_devel_kit-0.3.1 --add-module=../echo-nginx-module-0.62 --add-module=../xss-nginx-module-0.06 --add-module=../ngx_coolkit-0.2 --add-module=../set-misc-nginx-module-0.32 --add-module=../form-input-nginx-module-0.12 --add-module=../encrypted-session-nginx-module-0.08 --add-module=../srcache-nginx-module-0.32 --add-module=../ngx_lua-0.10.19 --add-module=../ngx_lua_upstream-0.07 --add-module=../headers-more-nginx-module-0.33 --add-module=../array-var-nginx-module-0.05 --add-module=../memc-nginx-module-0.19 --add-module=../redis2-nginx-module-0.15 --add-module=../redis-nginx-module-0.3.7 --add-module=../ngx_stream_lua-0.0.9 --with-ld-opt='-Wl,-rpath,/usr/local/openresty/luajit/lib -L/usr/local/openresty/zlib/lib -L/usr/local/openresty/pcre/lib -L/usr/local/openresty/openssl111/lib -Wl,-rpath,/usr/local/openresty/zlib/lib:/usr/local/openresty/pcre/lib:/usr/local/openresty/openssl111/lib' --with-cc='ccache gcc -fdiagnostics-color=always -g3' --with-pcre-jit --with-stream --with-stream_ssl_module --with-stream_ssl_preread_module --with-http_v2_module --without-mail_pop3_module --without-mail_imap_module --without-mail_smtp_module --with-http_stub_status_module --with-http_realip_module --with-http_addition_module --with-http_auth_request_module --with-http_secure_link_module --with-http_random_index_module --with-http_gzip_static_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-threads --with-compat --with-stream --with-http_ssl_module

local/openresty/luajit/lib/lua/5.1/?.so, context: init_worker_by_lua*
2020/11/27 09:20:35 [emerg] 245#246: lua pipe child close() socket 0.0.0.0:80 failed (9: Bad file descriptor)
2020/11/27 09:20:35 [emerg] 245#246: lua pipe child close() socket 0.0.0.0:80 failed (9: Bad file descriptor)
2020/11/27 09:20:35 [emerg] 245#246: lua pipe child close() socket 0.0.0.0:80 failed (9: Bad file descriptor)
2020/11/27 09:20:35 [emerg] 242#247: lua pipe child close() socket 0.0.0.0:80 failed (9: Bad file descriptor)
2020/11/27 09:20:35 [emerg] 242#247: lua pipe child close() socket 0.0.0.0:80 failed (9: Bad file descriptor)
2020/11/27 09:20:35 [emerg] 242#247: lua pipe child close() socket 0.0.0.0:80 failed (9: Bad file descriptor)