Bound the maximum buffer size for response headers.

http://code.google.com/p/chromium/issues/detail?id=3654

Review URL: http://codereview.chromium.org/7882

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@3827 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 70 insertions, 0 deletions

diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index d0a26d0..f7d7058 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -660,6 +660,10 @@ int HttpNetworkTransaction::DoReadHeadersComplete(int result) {
       int eoh = HttpUtil::LocateEndOfHeaders(
           header_buf_.get(), header_buf_len_, header_buf_http_offset_);
       if (eoh == -1) {
+        // Prevent growing the headers buffer indefinitely.
+        if (header_buf_len_ >= kMaxHeaderBufSize)
+          return ERR_RESPONSE_HEADERS_TOO_BIG;
+
         // Haven't found the end of headers yet, keep reading.
         next_state_ = STATE_READ_HEADERS;
         return OK;
diff --git a/net/http/http_network_transaction.h b/net/http/http_network_transaction.h
index 7fd0b3c..dc850b5 100644
--- a/net/http/http_network_transaction.h
+++ b/net/http/http_network_transaction.h
@@ -206,7 +206,17 @@ class HttpNetworkTransaction : public HttpTransaction {
   int header_buf_capacity_;
   int header_buf_len_;
   int header_buf_body_offset_;
+
+  // The number of bytes by which the header buffer is grown when it reaches
+  // capacity.
   enum { kHeaderBufInitialSize = 4096 };
+
+  // |kMaxHeaderBufSize| is the number of bytes that the response headers can
+  // grow to. If the body start is not found within this range of the
+  // response, the transaction will fail with ERR_RESPONSE_HEADERS_TOO_BIG.
+  // Note: |kMaxHeaderBufSize| should be a multiple of |kHeaderBufInitialSize|.
+  enum { kMaxHeaderBufSize = 32768 };  // 32 kilobytes.
+
   // The position where status line starts; -1 if not found yet.
   int header_buf_http_offset_;
 
diff --git a/net/http/http_network_transaction_unittest.cc b/net/http/http_network_transaction_unittest.cc
index 45fda4b..8568ec9 100644
--- a/net/http/http_network_transaction_unittest.cc
+++ b/net/http/http_network_transaction_unittest.cc
@@ -268,6 +268,23 @@ SimpleGetHelperResult SimpleGetHelper(MockRead data_reads[]) {
   return out;
 }
 
+// Create a long header list that consumes >= |size| bytes. The caller is
+// responsible for freeing the memory.
+char* MakeLargeHeadersString(int size) {
+  const char* row =
+      "SomeHeaderName: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\r\n";
+  const int sizeof_row = strlen(row);
+  const int num_rows = static_cast<int>(
+      ceil(static_cast<float>(size) / sizeof_row));
+  const int sizeof_data = num_rows * sizeof_row;
+  DCHECK(sizeof_data >= size);
+
+  char* data = new char[sizeof_data];
+  for (int i = 0; i < num_rows; ++i)
+    memcpy(data + i * sizeof_row, row, sizeof_row);
+  return data;
+}
+
 //-----------------------------------------------------------------------------
 
 TEST_F(HttpNetworkTransactionTest, Basic) {
@@ -802,3 +819,42 @@ TEST_F(HttpNetworkTransactionTest, BasicAuthProxyThenServer) {
   EXPECT_TRUE(response->auth_challenge.get() == NULL);
   EXPECT_EQ(100, response->headers->GetContentLength());
 }
+
+// Test reading a server response which has only headers, and no body.
+// After some maximum number of bytes is consumed, the transaction should
+// fail with ERR_RESPONSE_HEADERS_TOO_BIG.
+TEST_F(HttpNetworkTransactionTest, LargeHeadersNoBody) {
+  scoped_ptr<net::HttpTransaction> trans(new net::HttpNetworkTransaction(
+      CreateSession(), &mock_socket_factory));
+
+  net::HttpRequestInfo request;
+  request.method = "GET";
+  request.url = GURL("http://www.google.com/");
+  request.load_flags = 0;
+
+  // Respond with 50 kb of headers (we should fail after 32 kb).
+  scoped_array<char> large_headers_string(MakeLargeHeadersString(
+      50 * 1024));
+
+  MockRead data_reads[] = {
+    MockRead("HTTP/1.0 200 OK\r\n"),
+    MockRead(large_headers_string.get()),
+    MockRead("\r\nBODY"),
+    MockRead(false, net::OK),
+  };
+  MockSocket data;
+  data.reads = data_reads;
+  mock_sockets[0] = &data;
+  mock_sockets[1] = NULL;
+
+  TestCompletionCallback callback;
+
+  int rv = trans->Start(&request, &callback);
+  EXPECT_EQ(net::ERR_IO_PENDING, rv);
+
+  rv = callback.WaitForResult();
+  EXPECT_EQ(net::ERR_RESPONSE_HEADERS_TOO_BIG, rv);
+
+  const net::HttpResponseInfo* response = trans->GetResponseInfo();
+  EXPECT_TRUE(response == NULL);
+}