commit 085c2632bfd76875758e51584ce4b39935bcab8d
author Lei Zhang <thestig@chromium.org> Tue Sep 06 22:41:22 2022 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Sep 06 22:41:22 2022 +0000
tree e0d3ae798484a4c867da21117516c919044ed7ab
parent 105670a2f42c44c74f6386e0a125e4e659c2308e

Make size types more consistent within FlateModule.

Since the zlib compress() function expects uLong sizes, consistently use
unsigned long types to represent sizes in its caller.

Change-Id: I6094ab144fca19a249ad32a38eca859c26a8f35a
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/97591
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fxcodec/flate/flatemodule.cpp

diff --git a/core/fxcodec/flate/flatemodule.cpp b/core/fxcodec/flate/flatemodule.cpp
index a97c4be..d2a6340 100644
--- a/core/fxcodec/flate/flatemodule.cpp
+++ b/core/fxcodec/flate/flatemodule.cpp
@@ -64,7 +64,7 @@
 bool FlateCompress(unsigned char* dest_buf,
                    unsigned long* dest_size,
                    const unsigned char* src_buf,
-                   uint32_t src_size) {
+                   unsigned long src_size) {
   return compress(dest_buf, dest_size, src_buf, src_size) == Z_OK;
 }
 
@@ -868,15 +868,16 @@
 bool FlateModule::Encode(pdfium::span<const uint8_t> src_span,
                          std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
                          uint32_t* dest_size) {
-  const uint8_t* src_buf = src_span.data();
-  FX_SAFE_UINT32 src_size = src_span.size();
-  *dest_size = (src_size + src_size / 1000 + 12).ValueOrDie();
-  dest_buf->reset(FX_Alloc(uint8_t, *dest_size));
-  unsigned long temp_size = *dest_size;
-  if (!FlateCompress(dest_buf->get(), &temp_size, src_buf,
-                     src_size.ValueOrDie())) {
+  const unsigned long src_size =
+      pdfium::base::checked_cast<unsigned long>(src_span.size());
+  pdfium::base::CheckedNumeric<unsigned long> safe_dest_size = src_size;
+  safe_dest_size += src_size / 1000;
+  safe_dest_size += 12;
+  unsigned long temp_size = safe_dest_size.ValueOrDie();
+  dest_buf->reset(FX_Alloc(uint8_t, temp_size));
+  if (!FlateCompress(dest_buf->get(), &temp_size, src_span.data(), src_size))
     return false;
-  }
+
   *dest_size = pdfium::base::checked_cast<uint32_t>(temp_size);
   return true;
 }