fix laf string transform crash

1 files changed, 3 insertions, 0 deletions

diff --git a/instrumentation/SanitizerCoverageLTO.so.cc b/instrumentation/SanitizerCoverageLTO.so.cc
index 849b6eef..13a5e5fd 100644
--- a/instrumentation/SanitizerCoverageLTO.so.cc
+++ b/instrumentation/SanitizerCoverageLTO.so.cc
@@ -849,15 +849,18 @@ bool ModuleSanitizerCoverage::instrumentModule(
               thestring = Str2;
 
             optLen = thestring.length();
+            if (optLen < 2 || (optLen == 2 && !thestring[1])) { continue; }
 
             if (isMemcmp || isStrncmp || isStrncasecmp) {
 
               Value *      op2 = callInst->getArgOperand(2);
               ConstantInt *ilen = dyn_cast<ConstantInt>(op2);
+
               if (ilen) {
 
                 uint64_t literalLength = optLen;
                 optLen = ilen->getZExtValue();
+                if (optLen < 2) { continue; }
                 if (literalLength + 1 == optLen) {  // add null byte
                   thestring.append("\0", 1);
                   addedNull = true;