From 4ff0ca62e507e8fdbd5e0dfeed8acda407a36e56 Mon Sep 17 00:00:00 2001
From: Eugene Leviant <eleviant@accesssoftek.com>
Date: Thu, 13 Jun 2019 13:25:20 +0000
Subject: [PATCH] Extra error checking to ARMAttributeParser

The patch checks for subsection length as discussed in D63191


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363260 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Support/ARMAttributeParser.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/Support/ARMAttributeParser.cpp b/lib/Support/ARMAttributeParser.cpp
index 08b939a8734..65ee51f1319 100644
--- a/lib/Support/ARMAttributeParser.cpp
+++ b/lib/Support/ARMAttributeParser.cpp
@@ -709,6 +709,12 @@ void ARMAttributeParser::Parse(ArrayRef<uint8_t> Section, bool isLittle) {
       SW->indent();
     }
 
+    if (SectionLength == 0 || (SectionLength + Offset) > Section.size()) {
+      errs() << "invalid subsection length " << SectionLength << " at offset "
+             << Offset << "\n";
+      return;
+    }
+
     ParseSubsection(Section.data() + Offset, SectionLength);
     Offset = Offset + SectionLength;
 
-- 
2.40.0