From: Kevin Enderby <enderby@apple.com>
Date: Mon, 24 Jul 2017 20:33:41 +0000 (+0000)
Subject: Small tweak to one check in error handling to the dyld compact export
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=04cdb2eeb460026329bc765469ff557a3112fa19;p=llvm

Small tweak to one check in error handling to the dyld compact export
entries in libObject (done in r308690).  In the case when the last node
has no children setting State.Current = Children + 1; where that would be past
Trie.end() is actually ok since the pointer is not used with zero children.

rdar://33490512


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308924 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 8b85049ea63..579faf607c0 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -2789,13 +2789,13 @@ void ExportEntry::pushNode(uint64_t offset) {
       return;
     }
   }
-  if (Children + 1 >= Trie.end()) {
+  State.ChildCount = *Children;
+  if (State.ChildCount != 0 && Children + 1 >= Trie.end()) {
     *E = malformedError("byte for count of childern in export trie data at "
            "node: 0x" + utohexstr(offset) + " extends past end of trie data");
     moveToEnd();
     return;
   }
-  State.ChildCount = *Children;
   State.Current = Children + 1;
   State.NextChildIndex = 0;
   State.ParentStringLength = CumulativeString.size();