[PATCH] D95554: [BitcodeReader] Validate Strtab before accessing.

[Florian Hahn via Phabricator via llvm-commits]

fhahn updated this revision to Diff 320152.
fhahn added a comment.

Add missing sure and slightly re-word comment, thanks!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95554/new/

https://reviews.llvm.org/D95554

Files:
  llvm/lib/Bitcode/Reader/BitcodeReader.cpp
  llvm/test/Bitcode/invalid-record-strtab.ll
  llvm/test/Bitcode/invalid-record-strtab.ll.bc


Index: llvm/test/Bitcode/invalid-record-strtab.ll
===================================================================
--- /dev/null
+++ llvm/test/Bitcode/invalid-record-strtab.ll
@@ -0,0 +1,5 @@
+; Bitcode with an invalid record that indexes a name outside of strtab.
+
+; RUN: not llvm-dis %s.bc -o - 2>&1 | FileCheck %s
+
+; CHECK: error: Invalid record
Index: llvm/lib/Bitcode/Reader/BitcodeReader.cpp
===================================================================
--- llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3379,9 +3379,12 @@
 
   // Record[16] is the address space number.
 
-  // Check whether we have enough values to read a partition name.
-  if (Record.size() > 18)
+  // Check whether we have enough values to read a partition name. Also make
+  // sure Strtab has enough values.
+  if (Record.size() > 18 && Strtab.data() &&
+      Record[17] + Record[18] <= Strtab.size()) {
     Func->setPartition(StringRef(Strtab.data() + Record[17], Record[18]));
+  }
 
   Type *FullTy = PointerType::get(FullFTy, AddrSpace);
   assert(Func->getType() == flattenPointerTypes(FullTy) &&


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D95554.320152.patch
Type: text/x-patch
Size: 1144 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210129/24292917/attachment.bin>