Make SyzyAsan support the allocation > 1GB

syzygy/agent/asan/block.cc

Index: syzygy/agent/asan/block.cc
diff --git a/syzygy/agent/asan/block.cc b/syzygy/agent/asan/block.cc
index 3399d02c7a21483f652386775b76d9472b03bf4d..2e639e731ff165588291e6ccf572522b53cef35e 100644
--- a/syzygy/agent/asan/block.cc
+++ b/syzygy/agent/asan/block.cc
@@ -239,6 +239,11 @@ bool BlockPlanLayout(uint32_t chunk_size,
   DCHECK_GE(chunk_size, alignment);
   DCHECK(::common::IsPowerOfTwo(alignment));
 
+  // Prevent from trying to allocate a memory block bigger than what we can
+  // represent in the block header.
+  if (size > kBlockMaxAllocSize)
+    return false;
+
   // Calculate minimum redzone sizes that respect the parameters.
   uint32_t left_redzone_size = static_cast<uint32_t>(::common::AlignUp(
       std::max<uint32_t>(min_left_redzone_size, sizeof(BlockHeader)),