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

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 456df6dab8e410788b0aa9c0d38b92921c1440b2..aed1196f3cebdd83cba799f405c22b2793803e5f 100644 (file)
--- 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
new file mode 100644 (file)
index 0000000..a9e9c52
Binary files /dev/null and b/test/Bitcode/Inputs/invalid-GCTable-overflow.bc differ

diff --git a/test/Bitcode/invalid.test b/test/Bitcode/invalid.test
index 4aff5c0050117193b9bfb2056b60085aa78c96ac..2fe77989b2a50ba16261c9b2a6e3bbc3ce6752f6 100644 (file)
--- 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