Lua VM crash when using ngx.exec(), unsafe uri

[jayce]

See crash point: ngx_http_lua_control.c.

this code return NGX_HTTP_INTERNAL_SERVER_ERROR; causes the VM to crash.

detail:

• version openresty-1.9.7.3 and ngx_lua-0.10.0

• system log

  Oct 28 15:11:18 f02 kernel: nginx[14476]: segfault at 140d92420 ip 00007fe7f20ee40d sp 00007fff66396f20 error 4 in libluajit-5.1.so.2[7fe7f20e5000+c1000]
  Oct 28 15:11:39 f02 kernel: nginx[14489]: segfault at 141380a48 ip 00007fe7f20ee40d sp 00007fff66396ea0 error 4 in libluajit-5.1.so.2[7fe7f20e5000+c1000]
  Oct 28 15:11:59 f02 kernel: nginx[14486]: segfault at 141eb8f10 ip 00007fe7f20ee40d sp 00007fff66396ea0 error 4 in libluajit-5.1.so.2[7fe7f20e5000+c1000]

• nginx log

  2016/11/02 17:24:22 [error] 21115#0: *60 unsafe URI "/error_page/../" was detected *******

• configure

      location / {
          content_by_lua_block {
              ngx.log(ngx.ERR, "/error_page/ ")
              return ngx.exec("/error_page/../")
          }
      }

• test command

  wget http://localhost/ -SO/dev/null

[doujiang24]

@Jayce Thanks for your report. Already replied in https://groups.google.com/d/msg/openresty/R4TuNOYqO2o/wgvRoaKZCgAJ

Will you please create a PR, please don't forgot to add test case correspond to it :) Thanks again :)