Don't overflow GCTable

Summary: Bug found with AFL fuzz. Reviewers: rafael, dexonsmith Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D9361 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236200 91177308-0d34-0410-b5e6-96231b3b80d8
zoren · Apr 30, 2015 · deedba2 · deedba2
1 parent 36a398f
commit deedba2
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Showing 3 changed files with 6 additions and 1 deletion.
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2992,7 +2992,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume,
         // FIXME: Change to an error if non-default in 4.0.
         Func->setVisibility(GetDecodedVisibility(Record[7]));
       if (Record.size() > 8 && Record[8]) {
-        if (Record[8]-1 > GCTable.size())
+        if (Record[8]-1 >= GCTable.size())
           return Error("Invalid ID");
         Func->setGC(GCTable[Record[8]-1].c_str());
       }

diff --git a/test/Bitcode/Inputs/invalid-GCTable-overflow.bc b/test/Bitcode/Inputs/invalid-GCTable-overflow.bc
diff --git a/test/Bitcode/invalid.test b/test/Bitcode/invalid.test
@@ -122,3 +122,8 @@ RUN: not llvm-dis -disable-output %p/Inputs/invalid-load-pointer-type.bc 2>&1 |
 RUN:   FileCheck --check-prefix=LOAD-BAD-TYPE %s
 
 LOAD-BAD-TYPE: Load operand is not a pointer type
+
+RUN: not llvm-dis -disable-output %p/Inputs/invalid-GCTable-overflow.bc 2>&1 | \
+RUN:   FileCheck --check-prefix=GCTABLE-OFLOW %s
+
+GCTABLE-OFLOW: Invalid ID