Fixed socket leak with "return 444" in error_page (ticket #274).

Socket leak was observed in the following configuration:

    error_page 400 = /close;

    location = /close {
        return 444;
    }

The problem is that "return 444" triggers termination of the request,
and due to error_page termination thinks that it needs to use a posted
request to clear stack.  But at the early request processing where 400
errors are generated there are no ngx_http_run_posted_requests() calls,
so the request is only terminated after an external event.

Variants of the problem include "error_page 497" instead (ticket #695)
and various other errors generated during early request processing
(405, 414, 421, 494, 495, 496, 501, 505).

The same problem can be also triggered with "return 499" and "return 408"
as both codes trigger ngx_http_terminate_request(), much like "return 444".

To fix this, the patch adds ngx_http_run_posted_requests() calls to
ngx_http_process_request_line() and ngx_http_process_request_headers()
functions, and to ngx_http_v2_run_request() and ngx_http_v2_push_stream()
functions in HTTP/2.

Since the ngx_http_process_request() function is now only called via
other functions which call ngx_http_run_posted_requests(), the call
there is no longer needed and was removed.

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index d7e4d69f11cecec093f6a86e85a94773e290537a..c80df6e66510376fe407494f45035415c0f3f92b 100644 (file)
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -959,7 +959,7 @@ ngx_http_process_request_line(ngx_event_t *rev)
             n = ngx_http_read_request_header(r);
 
             if (n == NGX_AGAIN || n == NGX_ERROR) {
-                return;
+                break;
             }
         }
 
@@ -984,7 +984,7 @@ ngx_http_process_request_line(ngx_event_t *rev)
             }
 
             if (ngx_http_process_request_uri(r) != NGX_OK) {
-                return;
+                break;
             }
 
             if (r->schema_end) {
@@ -1003,16 +1003,16 @@ ngx_http_process_request_line(ngx_event_t *rev)
                     ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                   "client sent invalid host in request line");
                     ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
-                    return;
+                    break;
                 }
 
                 if (rc == NGX_ERROR) {
                     ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                    return;
+                    break;
                 }
 
                 if (ngx_http_set_virtual_server(r, &host) == NGX_ERROR) {
-                    return;
+                    break;
                 }
 
                 r->headers_in.server = host;
@@ -1024,11 +1024,11 @@ ngx_http_process_request_line(ngx_event_t *rev)
                     && ngx_http_set_virtual_server(r, &r->headers_in.server)
                        == NGX_ERROR)
                 {
-                    return;
+                    break;
                 }
 
                 ngx_http_process_request(r);
-                return;
+                break;
             }
 
 
@@ -1037,7 +1037,7 @@ ngx_http_process_request_line(ngx_event_t *rev)
                 != NGX_OK)
             {
                 ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                return;
+                break;
             }
 
             c->log->action = "reading client request headers";
@@ -1045,7 +1045,7 @@ ngx_http_process_request_line(ngx_event_t *rev)
             rev->handler = ngx_http_process_request_headers;
             ngx_http_process_request_headers(rev);
 
-            return;
+            break;
         }
 
         if (rc != NGX_AGAIN) {
@@ -1062,7 +1062,7 @@ ngx_http_process_request_line(ngx_event_t *rev)
                 ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
             }
 
-            return;
+            break;
         }
 
         /* NGX_AGAIN: a request line parsing is still incomplete */
@@ -1073,7 +1073,7 @@ ngx_http_process_request_line(ngx_event_t *rev)
 
             if (rv == NGX_ERROR) {
                 ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                return;
+                break;
             }
 
             if (rv == NGX_DECLINED) {
@@ -1083,10 +1083,12 @@ ngx_http_process_request_line(ngx_event_t *rev)
                 ngx_log_error(NGX_LOG_INFO, c->log, 0,
                               "client sent too long URI");
                 ngx_http_finalize_request(r, NGX_HTTP_REQUEST_URI_TOO_LARGE);
-                return;
+                break;
             }
         }
     }
+
+    ngx_http_run_posted_requests(c);
 }
 
 
@@ -1248,7 +1250,7 @@ ngx_http_process_request_headers(ngx_event_t *rev)
 
                 if (rv == NGX_ERROR) {
                     ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                    return;
+                    break;
                 }
 
                 if (rv == NGX_DECLINED) {
@@ -1261,7 +1263,7 @@ ngx_http_process_request_headers(ngx_event_t *rev)
                                       "client sent too large request");
                         ngx_http_finalize_request(r,
                                             NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
-                        return;
+                        break;
                     }
 
                     len = r->header_in->end - p;
@@ -1276,14 +1278,14 @@ ngx_http_process_request_headers(ngx_event_t *rev)
 
                     ngx_http_finalize_request(r,
                                             NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
-                    return;
+                    break;
                 }
             }
 
             n = ngx_http_read_request_header(r);
 
             if (n == NGX_AGAIN || n == NGX_ERROR) {
-                return;
+                break;
             }
         }
 
@@ -1313,7 +1315,7 @@ ngx_http_process_request_headers(ngx_event_t *rev)
             h = ngx_list_push(&r->headers_in.headers);
             if (h == NULL) {
                 ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                return;
+                break;
             }
 
             h->hash = r->header_hash;
@@ -1329,7 +1331,7 @@ ngx_http_process_request_headers(ngx_event_t *rev)
             h->lowcase_key = ngx_pnalloc(r->pool, h->key.len);
             if (h->lowcase_key == NULL) {
                 ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                return;
+                break;
             }
 
             if (h->key.len == r->lowcase_index) {
@@ -1343,7 +1345,7 @@ ngx_http_process_request_headers(ngx_event_t *rev)
                                h->lowcase_key, h->key.len);
 
             if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
-                return;
+                break;
             }
 
             ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
@@ -1367,12 +1369,12 @@ ngx_http_process_request_headers(ngx_event_t *rev)
             rc = ngx_http_process_request_header(r);
 
             if (rc != NGX_OK) {
-                return;
+                break;
             }
 
             ngx_http_process_request(r);
 
-            return;
+            break;
         }
 
         if (rc == NGX_AGAIN) {
@@ -1388,8 +1390,10 @@ ngx_http_process_request_headers(ngx_event_t *rev)
                       "client sent invalid header line");
 
         ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
-        return;
+        break;
     }
+
+    ngx_http_run_posted_requests(c);
 }
 
 
@@ -1944,8 +1948,6 @@ ngx_http_process_request(ngx_http_request_t *r)
     r->read_event_handler = ngx_http_block_reading;
 
     ngx_http_handler(r);
-
-    ngx_http_run_posted_requests(c);
 }
 
 

diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c
index e777019299ff8c9b22f5271841a5c9f265f9b901..b916ebdf6d37e277b371f8dd91b359986f8a605d 100644 (file)
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -2673,11 +2673,13 @@ error:
 
     if (rc == NGX_ABORT) {
         /* header handler has already finalized request */
+        ngx_http_run_posted_requests(fc);
         return NULL;
     }
 
     if (rc == NGX_DECLINED) {
         ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
+        ngx_http_run_posted_requests(fc);
         return NULL;
     }
 
@@ -3742,18 +3744,22 @@ ngx_http_v2_construct_cookie_header(ngx_http_request_t *r)
 static void
 ngx_http_v2_run_request(ngx_http_request_t *r)
 {
+    ngx_connection_t  *fc;
+
+    fc = r->connection;
+
     if (ngx_http_v2_construct_request_line(r) != NGX_OK) {
-        return;
+        goto failed;
     }
 
     if (ngx_http_v2_construct_cookie_header(r) != NGX_OK) {
-        return;
+        goto failed;
     }
 
     r->http_state = NGX_HTTP_PROCESS_REQUEST_STATE;
 
     if (ngx_http_process_request_header(r) != NGX_OK) {
-        return;
+        goto failed;
     }
 
     if (r->headers_in.content_length_n > 0 && r->stream->in_closed) {
@@ -3763,7 +3769,7 @@ ngx_http_v2_run_request(ngx_http_request_t *r)
         r->stream->skip_data = 1;
 
         ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
-        return;
+        goto failed;
     }
 
     if (r->headers_in.content_length_n == -1 && !r->stream->in_closed) {
@@ -3771,6 +3777,10 @@ ngx_http_v2_run_request(ngx_http_request_t *r)
     }
 
     ngx_http_process_request(r);
+
+failed:
+
+    ngx_http_run_posted_requests(fc);
 }