From: George Rimar <grimar@accesssoftek.com>
Date: Thu, 27 Oct 2016 11:44:56 +0000 (+0000)
Subject: [Object/ELF] - Do not allow overflow when checking section size/offset.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=464f0d78860090891079469ba7678656e7c5a12a;p=llvm

[Object/ELF] - Do not allow overflow when checking section size/offset.

Overflow was the reason of incorrect passing the check,
patch fixes the case.

Differentail revision: https://reviews.llvm.org/D25514

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285284 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h
index b6d4b804c27..d1de25d2821 100644
--- a/include/llvm/Object/ELF.h
+++ b/include/llvm/Object/ELF.h
@@ -229,7 +229,8 @@ ELFFile<ELFT>::getSectionContentsAsArray(const Elf_Shdr *Sec) const {
 
   if (Size % sizeof(T))
     return object_error::parse_failed;
-  if (Offset + Size > Buf.size())
+  if ((std::numeric_limits<uintX_t>::max() - Offset < Size) ||
+      Offset + Size > Buf.size())
     return object_error::parse_failed;
 
   const T *Start = reinterpret_cast<const T *>(base() + Offset);
diff --git a/test/Object/Inputs/invalid-section-size2.elf b/test/Object/Inputs/invalid-section-size2.elf
new file mode 100644
index 00000000000..5b7b5bca48a
Binary files /dev/null and b/test/Object/Inputs/invalid-section-size2.elf differ
diff --git a/test/Object/invalid.test b/test/Object/invalid.test
index 352917987de..a0016fef9d5 100644
--- a/test/Object/invalid.test
+++ b/test/Object/invalid.test
@@ -72,3 +72,7 @@ INVALID-RELOC-SH-OFFSET: Invalid data was encountered while parsing the file
 RUN: not llvm-readobj -t %p/Inputs/invalid-sections-address-alignment.x86-64 2>&1 | \
 RUN:   FileCheck --check-prefix=INVALID-SEC-ADDRESS-ALIGNMENT %s
 INVALID-SEC-ADDRESS-ALIGNMENT: Invalid data was encountered while parsing the file
+
+RUN: not llvm-readobj -t %p/Inputs/invalid-section-size2.elf 2>&1 | \
+RUN:   FileCheck --check-prefix=INVALID-SECTION-SIZE2 %s
+INVALID-SECTION-SIZE2: Invalid data was encountered while parsing the file.