Asserts and typed exception

Summary: Use asserts instead of throwing an exception directly. Introduce `BufferEndExceededException`. Reviewed By: thezhangwei Differential Revision: D66487161 fbshipit-source-id: bbacb8927c3f2c8b5e7cdc6fd1be7b3891ac9f5d
facebook · Nov 26, 2024 · 756b9b9 · 756b9b9
1 parent dd870ae
commit 756b9b9
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Showing 4 changed files with 20 additions and 12 deletions.
diff --git a/libredex/Debug.cpp b/libredex/Debug.cpp
@@ -285,6 +285,8 @@ void assert_fail(const char* expr,
 
   if (redex::g_throw_typed) {
     switch (type) {
+    case RedexError::BUFFER_END_EXCEEDED:
+      throw redex::BufferEndExceededException(msg);
     case RedexError::INVALID_DEX:
       throw redex::InvalidDexException(msg);
     default:

diff --git a/libredex/JarLoader.cpp b/libredex/JarLoader.cpp
@@ -41,9 +41,8 @@ namespace JarLoaderUtil {
 uint32_t read32(uint8_t*& buffer, uint8_t* buffer_end) {
   uint32_t rv;
   auto next = buffer + sizeof(uint32_t);
-  if (next > buffer_end) {
-    throw RedexException(RedexError::BUFFER_END_EXCEEDED);
-  }
+  always_assert_type_log(next <= buffer_end, BUFFER_END_EXCEEDED,
+                         "Buffer overflow");
   memcpy(&rv, buffer, sizeof(uint32_t));
   buffer = next;
   return htonl(rv);
@@ -52,18 +51,16 @@ uint32_t read32(uint8_t*& buffer, uint8_t* buffer_end) {
 uint16_t read16(uint8_t*& buffer, uint8_t* buffer_end) {
   uint16_t rv;
   auto next = buffer + sizeof(uint16_t);
-  if (next > buffer_end) {
-    throw RedexException(RedexError::BUFFER_END_EXCEEDED);
-  }
+  always_assert_type_log(next <= buffer_end, BUFFER_END_EXCEEDED,
+                         "Buffer overflow");
   memcpy(&rv, buffer, sizeof(uint16_t));
   buffer = next;
   return htons(rv);
 }
 
 uint8_t read8(uint8_t*& buffer, uint8_t* buffer_end) {
-  if (buffer >= buffer_end) {
-    throw RedexException(RedexError::BUFFER_END_EXCEEDED);
-  }
+  always_assert_type_log(buffer <= buffer_end, BUFFER_END_EXCEEDED,
+                         "Buffer overflow");
   return *buffer++;
 }
 } // namespace JarLoaderUtil
@@ -163,9 +160,8 @@ bool parse_cp_entry(uint8_t*& buffer, uint8_t* buffer_end, cp_entry& cpe) {
     cpe.len = read16(buffer, buffer_end);
     cpe.data = buffer;
     buffer += cpe.len;
-    if (buffer > buffer_end) {
-      throw RedexException(RedexError::BUFFER_END_EXCEEDED);
-    }
+    always_assert_type_log(buffer <= buffer_end, BUFFER_END_EXCEEDED,
+                           "Buffer overflow");
     return true;
   case CP_CONST_INVOKEDYN:
     std::cerr << "INVOKEDYN constant unsupported, Bailing\n";

diff --git a/libredex/RedexException.cpp b/libredex/RedexException.cpp
@@ -38,6 +38,8 @@ void assert_or_throw(bool cond,
   if (!cond) {
     if (redex::throw_typed_exception()) {
       switch (type) {
+      case RedexError::BUFFER_END_EXCEEDED:
+        throw redex::BufferEndExceededException(message, extra_info);
       case RedexError::INVALID_DEX:
         throw redex::InvalidDexException(message, extra_info);
       default:

diff --git a/libredex/RedexException.h b/libredex/RedexException.h
@@ -58,6 +58,14 @@ class InvalidDexException : public RedexException {
       : RedexException(RedexError::INVALID_DEX, message, extra_info) {}
 };
 
+class BufferEndExceededException : public RedexException {
+ public:
+  explicit BufferEndExceededException(
+      const std::string& message,
+      const std::map<std::string, std::string>& extra_info = {})
+      : RedexException(RedexError::BUFFER_END_EXCEEDED, message, extra_info) {}
+};
+
 } // namespace redex
 
 void assert_or_throw(bool cond,