Opened 3 weeks ago

Closed 11 days ago

#2214 closed defect (invalid)

The NGX_CHANGEBIN_SIGNAL-induced restart does not preserve the original environment variables

Reported by: Aristarkh Zagorodnikov Owned by:
Priority: minor Milestone:
Component: nginx-core Version:
Keywords: Cc:
uname -a: Linux rainbow1-21 5.8.0-59-generic #66~20.04.1-Ubuntu SMP Thu Jun 17 11:14:10 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
nginx -V: nginx version: nginx/1.21.1
built by gcc 9.3.0 (Ubuntu 9.3.0-10ubuntu2)
built with OpenSSL 1.1.1f 31 Mar 2020
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-cc-opt='-g -O2 -fdebug-prefix-map=/data/builder/debuild/nginx-1.21.1/debian/debuild-base/nginx-1.21.1=. -fstack-protector-strong -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie'

Description

Hi,

The NGX_CHANGEBIN_SIGNAL (SIGUSR2) currently does not preserve the externally-set environment when restarting the master process. For example, consider the LD_PRELOAD environment variable that is set in the systemd override configuration file. When NGX_CHANGEBIN_SIGNAL is set to nginx master process, it does not start the new process with the environment variable LD_PRELOAD set. Adding this variable to NGINX configuration via the env directive doesn't help, because it properly affects the dynamic linking for the child processes.
I believe that the NGX_CHANGEBIN_SIGNAL handler should preserve the environment when launching a new master process because if it is not preserved, different shared libraries could silently be loaded after a binary upgrade.

Thanks for taking a look.

Change History (2)

comment:1 by Maxim Dounin, 3 weeks ago

Adding this variable to NGINX configuration via the env directive doesn't help, because it properly affects the dynamic linking for the child processes.

Could you please elaborate a bit more on why the env directive does not work for you?

Note that the env directive is explicitly documented to control, among others, the environment variables "inherited during a live upgrade of an executable file", that is, exactly the behaviour you observe.

comment:2 by Maxim Dounin, 11 days ago

Resolution: invalid
Status: newclosed

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