[PATCH] D37447: [Decompression] Fail gracefully when out of memory

[Jonas Devlieghere via Phabricator via llvm-commits]

JDevlieghere updated this revision to Diff 113809.
JDevlieghere added a subscriber: kcc.
JDevlieghere added a comment.

Thanks! I've updated the diff to include the section name.

My test case is the one from oss-fuzz, so unfortunately the section name doesn't say much. I don't know enough about the binary file format to change it.


Repository:
  rL LLVM

https://reviews.llvm.org/D37447

Files:
  include/llvm/Object/Decompressor.h
  lib/Object/Decompressor.cpp
  test/tools/llvm-dwarfdump/Inputs/dwarf-invalid-compression
  test/tools/llvm-dwarfdump/dwarf-invalid-compression.test


Index: test/tools/llvm-dwarfdump/dwarf-invalid-compression.test
===================================================================
--- /dev/null
+++ test/tools/llvm-dwarfdump/dwarf-invalid-compression.test
@@ -0,0 +1,2 @@
+RUN: not llvm-dwarfdump %p/Inputs/dwarf-invalid-compression 2>&1 | FileCheck %s
+CHECK: Decompression of ' ' failed: unable to allocate 2314885530818453536 bytes.
Index: lib/Object/Decompressor.cpp
===================================================================
--- lib/Object/Decompressor.cpp
+++ lib/Object/Decompressor.cpp
@@ -23,16 +23,16 @@
   if (!zlib::isAvailable())
     return createError("zlib is not available");
 
-  Decompressor D(Data);
+  Decompressor D(Name, Data);
   Error Err = isGnuStyle(Name) ? D.consumeCompressedGnuHeader()
                                : D.consumeCompressedZLibHeader(Is64Bit, IsLE);
   if (Err)
     return std::move(Err);
   return D;
 }
 
-Decompressor::Decompressor(StringRef Data)
-    : SectionData(Data), DecompressedSize(0) {}
+Decompressor::Decompressor(StringRef Name, StringRef Data)
+    : SectionName(Name), SectionData(Data), DecompressedSize(0) {}
 
 Error Decompressor::consumeCompressedGnuHeader() {
   if (!SectionData.startswith("ZLIB"))
@@ -92,3 +92,11 @@
   size_t Size = Buffer.size();
   return zlib::uncompress(SectionData, Buffer.data(), Size);
 }
+
+void Decompressor::outOfMemoryHandler(void *Data, const std::string &Message,
+                                      bool) {
+  auto *D = static_cast<class Decompressor *>(Data);
+  report_fatal_error("Decompression of '" + D->getSectionName() +
+                     "' failed: unable to allocate " +
+                     Twine(D->getDecompressedSize()) + " bytes.");
+}
Index: include/llvm/Object/Decompressor.h
===================================================================
--- include/llvm/Object/Decompressor.h
+++ include/llvm/Object/Decompressor.h
@@ -13,6 +13,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/ErrorHandling.h"
 
 namespace llvm {
 namespace object {
@@ -31,14 +32,19 @@
   /// @brief Resize the buffer and uncompress section data into it.
   /// @param Out         Destination buffer.
   template <class T> Error resizeAndDecompress(T &Out) {
+    install_bad_alloc_error_handler(outOfMemoryHandler, this);
     Out.resize(DecompressedSize);
+    remove_bad_alloc_error_handler();
     return decompress({Out.data(), (size_t)DecompressedSize});
   }
 
   /// @brief Uncompress section data to raw buffer provided.
   /// @param Buffer      Destination buffer.
   Error decompress(MutableArrayRef<char> Buffer);
 
+  /// @brief Return name of the section that is being decompressed.
+  StringRef getSectionName() { return SectionData; }
+
   /// @brief Return memory buffer size required for decompression.
   uint64_t getDecompressedSize() { return DecompressedSize; }
 
@@ -52,11 +58,14 @@
   static bool isGnuStyle(StringRef Name);
 
 private:
-  Decompressor(StringRef Data);
+  static void outOfMemoryHandler(void *Data, const std::string &Message, bool);
+
+  Decompressor(StringRef Name, StringRef Data);
 
   Error consumeCompressedGnuHeader();
   Error consumeCompressedZLibHeader(bool Is64Bit, bool IsLittleEndian);
 
+  StringRef SectionName;
   StringRef SectionData;
   uint64_t DecompressedSize;
 };


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