Revert 56796 - Sbox IPC fix

Tests failing on vista 

BUG=52682
TEST=included


Review URL: http://codereview.chromium.org/3142022

TBR=cpu@chromium.org
Review URL: http://codereview.chromium.org/3122031

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@56798 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 39 insertions, 72 deletions

diff --git a/sandbox/src/crosscall_params.h b/sandbox/src/crosscall_params.h
index 4c1e4fe..939925c 100644
--- a/sandbox/src/crosscall_params.h
+++ b/sandbox/src/crosscall_params.h
@@ -169,33 +169,30 @@ class CrossCallParams {
 // blob to be complex.
 //
 // As is, this class assumes that the layout of the blob is as follows. Assume
-// that NUMBER_PARAMS = 2 and a 32-bit build:
+// that NUMBER_PARAMS = 2:
 //
-// [ tag                4 bytes]
-// [ IsOnOut            4 bytes]
-// [ call return       52 bytes]
-// [ params count       4 bytes]
-// [ parameter 0 type   4 bytes]
-// [ parameter 0 offset 4 bytes] ---delta to ---\
-// [ parameter 0 size   4 bytes]                |
-// [ parameter 1 type   4 bytes]                |
-// [ parameter 1 offset 4 bytes] ---------------|--\
-// [ parameter 1 size   4 bytes]                |  |
-// [ parameter 2 type   4 bytes]                |  |
-// [ parameter 2 offset 4 bytes] ----------------------\
-// [ parameter 2 size   4 bytes]                |  |   |
-// |---------------------------|                |  |   |
-// | value 0     (x bytes)     | <--------------/  |   |
-// | value 1     (y bytes)     | <-----------------/   |
-// |                           |                       |
-// | end of buffer             | <---------------------/
-// |---------------------------|
+// [ tag              4 bytes]
+// [ IsOnOut          4 bytes]
+// [ call return     52 bytes]
+// [ params count     4 bytes]
+// [ parameter 0 type 4 bytes]
+// [ parameter 0 /\   4 bytes] ---delta to ---\
+// [ parameter 0 size 4 bytes]                |
+// [ parameter 1 type 4 bytes]                |
+// [ parameter 1 /\   4 bytes]                |
+// [ parameter 1 size 4 bytes]                |
+// [ parameter 2 type 4 bytes]                |
+// [ parameter 2 /\   4 bytes] ----------------------\
+// [ parameter 2 size 4 bytes]                |      |
+// |-------------------------|                |      |
+// |                         | <--------------/      |
+// |                         |                       |
+// |                         | <---------------------/
+// |-------------------------|
 //
 // Note that the actual number of params is NUMBER_PARAMS + 1
 // so that the size of each actual param can be computed from the difference
-// between one parameter and the next down. The offset of the last param
-// points to the end of the buffer and the type and size are undefined.
-//
+// between one parameter and the next down
 template <size_t NUMBER_PARAMS, size_t BLOCK_SIZE>
 class ActualCallParams : public CrossCallParams {
  public:
@@ -212,14 +209,6 @@ class ActualCallParams : public CrossCallParams {
     param_info_[0].offset_ = parameters_ - reinterpret_cast<char*>(this);
   }
 
-  // Testing-only method. Allows setting the apparent size to a wrong value.
-  // returns the previous size.
-  size_t OverrideSize(size_t new_size) {
-    size_t previous_size = param_info_[NUMBER_PARAMS].offset_;
-    param_info_[NUMBER_PARAMS].offset_ = new_size;
-    return previous_size;
-  }
-
   // Copies each paramter into the internal buffer. For each you must supply:
   // index: 0 for the first param, 1 for the next an so on
   bool CopyParamIn(size_t index, const void* parameter_address, size_t size,
diff --git a/sandbox/src/crosscall_server.cc b/sandbox/src/crosscall_server.cc
index 5063ce6..da43c69 100644
--- a/sandbox/src/crosscall_server.cc
+++ b/sandbox/src/crosscall_server.cc
@@ -85,8 +85,6 @@ void CrossCallParamsEx::operator delete(void* raw_memory) throw() {
 CrossCallParamsEx* CrossCallParamsEx::CreateFromBuffer(void* buffer_base,
                                                        size_t buffer_size,
                                                        size_t* output_size) {
-  // IMPORTANT: Everything inside buffer_base and derived from it such
-  // as param_count and declared_size is untrusted.
   if (NULL == buffer_base) {
     return NULL;
   }
@@ -96,12 +94,10 @@ CrossCallParamsEx* CrossCallParamsEx::CreateFromBuffer(void* buffer_base,
   if (buffer_size > kMaxBufferSize) {
     return NULL;
   }
-
   char* backing_mem = NULL;
   size_t param_count = 0;
-  size_t declared_size;
-  size_t min_declared_size;
   CrossCallParamsEx* copied_params = NULL;
+  size_t actual_size;
 
   // Touching the untrusted buffer is done under a SEH try block. This
   // will catch memory access violations so we don't crash.
@@ -111,28 +107,30 @@ CrossCallParamsEx* CrossCallParamsEx::CreateFromBuffer(void* buffer_base,
     // Check against the minimum size given the number of stated params
     // if too small we bail out.
     param_count = call_params->GetParamsCount();
-
-    min_declared_size =
-        sizeof(CrossCallParamsEx) + (param_count * sizeof(ParamInfo));
-
-    if (min_declared_size < sizeof(CrossCallParams) ||
-       (buffer_size < min_declared_size)) {
-      // Integer overflow or computed size bigger than untrusted buffer.
+    if ((buffer_size - sizeof(CrossCallParams)) <
+        (sizeof(ptrdiff_t) * (param_count + 1))) {
+      // This test is subject to integer overflow but the next is not.
       return NULL;
     }
 
-    declared_size = GetActualBufferSize(param_count, buffer_base);
-    if ((declared_size > buffer_size) ||
-        (declared_size < min_declared_size)) {
-      // declared size is bigger than buffer or smaller than computed size.
+    actual_size = GetActualBufferSize(param_count, buffer_base);
+    if ((actual_size > buffer_size) || (0 == actual_size)) {
+      // It is too big or too many declared parameters.
       return NULL;
     }
 
     // Now we copy the actual amount of the message.
-    *output_size = declared_size;
-    backing_mem = new char[declared_size];
-    copied_params = reinterpret_cast<CrossCallParamsEx*>(backing_mem);
-    memcpy(backing_mem, call_params, declared_size);
+    actual_size += sizeof(ParamInfo);  // To get the last offset.
+    *output_size = actual_size;
+    backing_mem = new char[actual_size];
+    memset(backing_mem, 0, actual_size);
+    // Note that this is a placement new.
+#pragma warning(push)
+#pragma warning(disable: 4291)  // No matching operator delete.
+    // TODO(cpu): Remove this warning.
+    copied_params = new(backing_mem)CrossCallParamsEx();
+#pragma warning(pop)
+    memcpy(backing_mem, call_params, actual_size);
 
   } __except(EXCEPTION_EXECUTE_HANDLER) {
     // In case of a windows exception we know it occurred while touching the
@@ -140,9 +138,7 @@ CrossCallParamsEx* CrossCallParamsEx::CreateFromBuffer(void* buffer_base,
     return NULL;
   }
 
-  const char* last_byte = &backing_mem[declared_size - 1];
-  const char* first_byte = &backing_mem[min_declared_size];
-
+  char* last_byte = &backing_mem[actual_size - 1];
   // Verify here that all and each parameters make sense. This is done in the
   // local copy.
   for (size_t ix =0; ix != param_count; ++ix) {
@@ -153,7 +149,6 @@ CrossCallParamsEx* CrossCallParamsEx::CreateFromBuffer(void* buffer_base,
     if ((NULL == address) ||               // No null params.
         (INVALID_TYPE >= type) || (LAST_TYPE <= type) ||  // Unknown type.
         (address < backing_mem) ||         // Start cannot point before buffer.
-        (address < first_byte) ||          // Start cannot point too low.
         (address > last_byte) ||           // Start cannot point past buffer.
         ((address + size) < address) ||    // Invalid size.
         ((address + size) > last_byte)) {  // End cannot point past buffer.
diff --git a/sandbox/src/ipc_unittest.cc b/sandbox/src/ipc_unittest.cc
index 7686242..909f144 100644
--- a/sandbox/src/ipc_unittest.cc
+++ b/sandbox/src/ipc_unittest.cc
@@ -332,23 +332,6 @@ TEST(IPCTest, CrossCallValidation) {
     EXPECT_TRUE(NULL == ccp);
   }
 #endif  // defined(NDEBUG)
-
-  ActualCallParams<1, 256> params_3(kTag, 1);
-  params_3.CopyParamIn(0, &value, sizeof(value), false, ULONG_TYPE);
-  buffer = const_cast<void*>(params_3.GetBuffer());
-  EXPECT_TRUE(NULL != buffer);
-
-  size_t correct_size = params_3.OverrideSize(1);
-  ccp = CrossCallParamsEx::CreateFromBuffer(buffer, 256, &out_size);
-  EXPECT_TRUE(NULL == ccp);
-
-  params_3.OverrideSize(correct_size - 4);
-  ccp = CrossCallParamsEx::CreateFromBuffer(buffer, 256, &out_size);
-  EXPECT_TRUE(NULL == ccp);
-
-  params_3.OverrideSize(correct_size);
-  ccp = CrossCallParamsEx::CreateFromBuffer(buffer, 256, &out_size);
-  EXPECT_TRUE(NULL != ccp);
 }
 
 // This structure is passed to the mock server threads to simulate