From 24f3e102a678e2d102ac5660371fba1c2cfccd25 Mon Sep 17 00:00:00 2001
From: Owen Reynolds <gbreynoo@gmail.com>
Date: Tue, 23 Jul 2019 14:44:21 +0000
Subject: [llvm-ar] Fix support for archives with members larger than 4GB

llvm-ar outputs a strange error message when handling archives with
members larger than 4GB due to not checking file size when passing the
value as an unsigned 32 bit integer. This overflow issue caused
malformed archives to be created.:

https://bugs.llvm.org/show_bug.cgi?id=38058

This change allows for members above 4GB and will error in a case that
is over the formats size limit, a 10 digit decimal integer.

Differential Revision: https://reviews.llvm.org/D65093

llvm-svn: 366813
---
 llvm/lib/Object/ArchiveWriter.cpp | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

(limited to 'llvm/lib/Object/ArchiveWriter.cpp')

diff --git a/llvm/lib/Object/ArchiveWriter.cpp b/llvm/lib/Object/ArchiveWriter.cpp
index 228f6b40c5e..f12f1e521a9 100644
--- a/llvm/lib/Object/ArchiveWriter.cpp
+++ b/llvm/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 print(raw_ostream &Out, object::Archive::Kind Kind, T Val) {
 
 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 @@ static void
 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 @@ printGNUSmallMemberHeader(raw_ostream &Out, StringRef Name,
 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 @@ static void
 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 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
       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 =
-- 
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