bugfix: nginx could crash on request fialization when running the cosocket cleanup handler due to the lack of check of the ctx pointer. thanks shaneeb for reporting this in github issue #110.

Author: agentzh

src/ngx_http_lua_socket.c

@@ -2036,16 +2036,19 @@ ngx_http_lua_socket_finalize(ngx_http_request_t *r,
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "lua finalize socket");
 
-    if (u->bufs_in) {
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
 
-        ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+    if (ctx && u->bufs_in) {
 
         ll = &u->bufs_in;
         for (cl = u->bufs_in; cl; cl = cl->next) {
+            dd("bufs_in chain: %p, next %p", cl, cl->next);
             cl->buf->pos = cl->buf->last;
             ll = &cl->next;
         }
 
+        dd("ctx: %p", ctx);
+        dd("free recv bufs: %p", ctx->free_recv_bufs);
         *ll = ctx->free_recv_bufs;
         ctx->free_recv_bufs = u->bufs_in;
         u->bufs_in = NULL;

t/068-socket-keepalive.t

@@ -5,7 +5,7 @@ use Test::Nginx::Socket;
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 5 + 10);
+plan tests => repeat_each() * (blocks() * 5 + 8);
 
 our $HtmlDir = html_dir;
 
@@ -899,3 +899,62 @@ lua socket get keepalive peer: using connection
 [error]
 [alert]
 
+
+
+=== TEST 13: github issue #110: ngx.exit with HTTP_NOT_FOUND causes worker process to exit
+--- http_config eval
+    "lua_package_path '$::HtmlDir/?.lua;./?.lua';"
+--- config
+    error_page 404 /404.html;
+    location /t {
+        set $port $TEST_NGINX_MEMCACHED_PORT;
+        access_by_lua '
+            local test = require "test"
+            local port = ngx.var.port
+            test.go(port)
+            ngx.exit(404)
+        ';
+        echo hello;
+    }
+--- user_files
+>>> 404.html
+Not found, dear...
+>>> test.lua
+module("test", package.seeall)
+
+function go(port)
+    local sock = ngx.socket.tcp()
+    local ok, err = sock:connect("127.0.0.1", port)
+    if not ok then
+        ngx.log(ngx.ERR, "failed to connect: ", err)
+        return
+    end
+
+    local req = "flush_all\r\n"
+
+    local bytes, err = sock:send(req)
+    if not bytes then
+        ngx.log(ngx.ERR, "failed to send request: ", err)
+        return
+    end
+
+    local line, err, part = sock:receive()
+    if not line then
+        ngx.log(ngx.ERR, "failed to receive a line: ", err, " [", part, "]")
+        return
+    end
+
+    -- local ok, err = sock:setkeepalive()
+    -- if not ok then
+        -- ngx.log(ngx.ERR, "failed to set reusable: ", err)
+        -- return
+    -- end
+end
+--- request
+GET /t
+--- response_body
+Not found, dear...
+--- error_code: 404
+--- no_error_log
+[error]
+