Port r183666 to identify_magic.

It will be tested in the next commit which moves another user to identify_magic.

Original message:

Fix an out of bounds array access.

We were looking at Magic[5] without checking Length. Since this path would not
return unless Length >= 18 anyway, just move the >= 18 check up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183753 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/PathV2.cpp b/lib/Support/PathV2.cpp
index 1546e0781dd0f1781d49b748d8a8444f6e34040c..9533e78eada3451da7b19e1d068aef9476b992d4 100644 (file)
--- a/lib/Support/PathV2.cpp
+++ b/lib/Support/PathV2.cpp
@@ -788,11 +788,12 @@ error_code has_magic(const Twine &path, const Twine &magic, bool &result) {
       break;
 
     case '\177':
-      if (Magic[1] == 'E' && Magic[2] == 'L' && Magic[3] == 'F') {
+      if (Magic.size() >= 18 && Magic[1] == 'E' && Magic[2] == 'L' &&
+          Magic[3] == 'F') {
         bool Data2MSB = Magic[5] == 2;
         unsigned high = Data2MSB ? 16 : 17;
         unsigned low  = Data2MSB ? 17 : 16;
-        if (Magic.size() >= 18 && Magic[high] == 0)
+        if (Magic[high] == 0)
           switch (Magic[low]) {
             default: break;
             case 1: return file_magic::elf_relocatable;