Index: include/llvm/Object/Archive.h
===================================================================
--- include/llvm/Object/Archive.h
+++ include/llvm/Object/Archive.h
@@ -48,8 +48,7 @@
   /// Get the name looking up long names.
   Expected<StringRef> getName(uint64_t Size) const;
 
-  /// Members are not larger than 4GB.
-  Expected<uint32_t> getSize() const;
+  Expected<uint64_t> getSize() const;
 
   Expected<sys::fs::perms> getAccessMode() const;
   Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const;
@@ -221,6 +220,9 @@
   Archive(MemoryBufferRef Source, Error &Err);
   static Expected<std::unique_ptr<Archive>> create(MemoryBufferRef Source);
 
+  /// Size field is 10 decimal digits long
+  static const uint64_t MaxMemberSize = 9999999999;
+
   enum Kind {
     K_GNU,
     K_GNU64,
Index: lib/Object/Archive.cpp
===================================================================
--- lib/Object/Archive.cpp
+++ lib/Object/Archive.cpp
@@ -223,8 +223,8 @@
   return Name.drop_back(1);
 }
 
-Expected<uint32_t> ArchiveMemberHeader::getSize() const {
-  uint32_t Ret;
+Expected<uint64_t> ArchiveMemberHeader::getSize() const {
+  uint64_t Ret;
   if (StringRef(ArMemHdr->Size,
                 sizeof(ArMemHdr->Size)).rtrim(" ").getAsInteger(10, Ret)) {
     std::string Buf;
Index: lib/Object/ArchiveWriter.cpp
===================================================================
--- lib/Object/ArchiveWriter.cpp
+++ lib/Object/ArchiveWriter.cpp
@@ -16,6 +16,7 @@
 #include "llvm/BinaryFormat/Magic.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/Object/Archive.h"
+#include "llvm/Object/Error.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Object/SymbolicFile.h"
 #include "llvm/Support/EndianStream.h"
@@ -147,7 +148,7 @@
 
 static void printRestOfMemberHeader(
     raw_ostream &Out, const sys::TimePoint<std::chrono::seconds> &ModTime,
-    unsigned UID, unsigned GID, unsigned Perms, unsigned Size) {
+    unsigned UID, unsigned GID, unsigned Perms, uint64_t Size) {
   printWithSpacePadding(Out, sys::toTimeT(ModTime), 12);
 
   // The format has only 6 chars for uid and gid. Truncate if the provided
@@ -164,7 +165,7 @@
 printGNUSmallMemberHeader(raw_ostream &Out, StringRef Name,
                           const sys::TimePoint<std::chrono::seconds> &ModTime,
                           unsigned UID, unsigned GID, unsigned Perms,
-                          unsigned Size) {
+                          uint64_t Size) {
   printWithSpacePadding(Out, Twine(Name) + "/", 16);
   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 }
@@ -172,8 +173,7 @@
 static void
 printBSDMemberHeader(raw_ostream &Out, uint64_t Pos, StringRef Name,
                      const sys::TimePoint<std::chrono::seconds> &ModTime,
-                     unsigned UID, unsigned GID, unsigned Perms,
-                     unsigned Size) {
+                     unsigned UID, unsigned GID, unsigned Perms, uint64_t Size) {
   uint64_t PosAfterHeader = Pos + 60 + Name.size();
   // Pad so that even 64 bit object files are aligned.
   unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
@@ -208,7 +208,7 @@
 printMemberHeader(raw_ostream &Out, uint64_t Pos, raw_ostream &StringTable,
                   StringMap<uint64_t> &MemberNames, object::Archive::Kind Kind,
                   bool Thin, const NewArchiveMember &M,
-                  sys::TimePoint<std::chrono::seconds> ModTime, unsigned Size) {
+                  sys::TimePoint<std::chrono::seconds> ModTime, uint64_t Size) {
   if (isBSDLike(Kind))
     return printBSDMemberHeader(Out, Pos, M.MemberName, ModTime, M.UID, M.GID,
                                 M.Perms, Size);
@@ -474,8 +474,17 @@
       ModTime = sys::toTimePoint(FilenameCount[M.MemberName]++);
     else
       ModTime = M.ModTime;
+
+    uint64_t Size = Buf.getBufferSize() + MemberPadding;
+    if (Size > object::Archive::MaxMemberSize) {
+      std::string StringMsg =
+          "File " + M.MemberName.str() + " exceeds size limit";
+      return make_error<object::GenericBinaryError>(
+          std::move(StringMsg), object::object_error::parse_failed);
+    }
+
     printMemberHeader(Out, Pos, StringTable, MemberNames, Kind, Thin, M,
-                      ModTime, Buf.getBufferSize() + MemberPadding);
+                      ModTime, Size);
     Out.flush();
 
     Expected<std::vector<unsigned>> Symbols =