Make sure the CastInst is valid before trying to create it

Bug found with afl-fuzz.

llvm-svn: 249396

3 files changed, 9 insertions, 1 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 2893eaef0fb..ce6790be713 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3863,7 +3863,10 @@ std::error_code BitcodeReader::parseFunctionBody(Function *F) {
           CurBB->getInstList().push_back(Temp);
         }
       } else {
-        I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
+        auto CastOp = (Instruction::CastOps)Opc;
+        if (!CastInst::castIsValid(CastOp, Op, ResTy))
+          return error("Invalid cast");
+        I = CastInst::Create(CastOp, Op, ResTy);
       }
       InstructionList.push_back(I);
       break;
diff --git a/llvm/test/Bitcode/Inputs/invalid-cast.bc b/llvm/test/Bitcode/Inputs/invalid-cast.bc
new file mode 100644
index 00000000000..a8b82f3e286
--- /dev/null
+++ b/llvm/test/Bitcode/Inputs/invalid-cast.bc
diff --git a/llvm/test/Bitcode/invalid.test b/llvm/test/Bitcode/invalid.test
index 0aab553bb61..69104046df2 100644
--- a/llvm/test/Bitcode/invalid.test
+++ b/llvm/test/Bitcode/invalid.test
@@ -113,6 +113,11 @@ RUN:   FileCheck --check-prefix=ELEMENT-TYPE %s
 
 ELEMENT-TYPE: Invalid type
 
+RUN: not llvm-dis -disable-output %p/Inputs/invalid-cast.bc 2>&1 | \
+RUN:   FileCheck --check-prefix=INVALID-CAST %s
+
+INVALID-CAST: Invalid cast
+
 RUN: not llvm-dis -disable-output %p/Inputs/invalid-array-op-not-2nd-to-last.bc 2>&1 | \
 RUN:   FileCheck --check-prefix=ARRAY-NOT-2LAST %s