Merge pull request #242 from yusmer96-maker/yusmer96-maker-patch-1

Implement overflow check in MaxCompressedLength function

snappy.cc

diff --git a/snappy.cc b/snappy.cc
index ab61792..9826151 100644
--- a/snappy.cc
+++ b/snappy.cc
@@ -74,6 +74,7 @@
 #include <cstdint>
 #include <cstdio>
 #include <cstring>
+#include <limits>
 #include <memory>
 #include <string>
 #include <utility>
@@ -194,6 +195,11 @@
 }  // namespace
 
 size_t MaxCompressedLength(size_t source_bytes) {
+  // Avoid integer overflow that could cause undersized buffer allocations.
+  // Return std::numeric_limits<size_t>::max() to force a controlled allocation failure.
+  if (source_bytes > (std::numeric_limits<size_t>::max() - 32) / 7 * 6) {
+    return std::numeric_limits<size_t>::max();
+  }
   // Compressed data can be defined as:
   //    compressed := item* literal*
   //    item       := literal* copy