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Prevent segfault while calling srv.ssl_cert_handle #1055

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Prevent segfault while calling srv.ssl_cert_handle #1055

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10 changes: 8 additions & 2 deletions src/ngx_http_lua_ssl_certby.c
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Expand Up @@ -298,8 +298,14 @@ ngx_http_lua_ssl_cert_handler(ngx_ssl_conn_t *ssl_conn, void *data)

c->log->action = "loading SSL certificate by lua";

rc = lscf->srv.ssl_cert_handler(r, lscf, L);

if (lscf->srv.ssl_cert_handler) {
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@agentzh agentzh Apr 25, 2017 •
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This pointer can never be NULL when it is already in this ngx_http_lua_ssl_cert_handler function. And we never observe NULL pointers in some user company's global SSL gateway network. I guess it's something else, like some 3rd-party NGINX C modules or 3rd-party Lua C or FFI libraries you are using, which corrupt memory. This does not look like the culprit. Better dig things up instead of working around the real issue which might be somewhere else.

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@petrovich-ua petrovich-ua Apr 25, 2017

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I agree, I have to go deeper and find out the real reason of null pointer.
But, anyway,

  • There is only one 3rd party module I use, besides shipped with nginx and openresty: https://github.com/newobj/nginx-x-rid-header/blob/master/ngx_x_rid_header_module.c, it's quite simple and i'ts not the culprit for my mind.
  • I have used my build of nginx for rather long time, with no segfaults just untill I've added only one line: "ssl_certificate_by_lua_block { return }"
  • there are no any other block of lua code in my config
  • It seems, I've somehow localized this issue,. My nginx crashes after request from IP addresses which use okhttp/3.3.1 client (it's java http client for android)

Some more info I've posted to https://groups.google.com/forum/#!topic/openresty-en/ym1oPD9fyLo

rc = lscf->srv.ssl_cert_handler(r, lscf, L);
} else {
ngx_ssl_error(NGX_LOG_ALERT, c->log, 0,
"srv.ssl_cert_handler is null");
goto failed;
}

if (rc >= NGX_OK || rc == NGX_ERROR) {
cctx->done = 1;

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