From 3342aa751d8e9102449e1739b38a25c40ab18e81 Mon Sep 17 00:00:00 2001
From: vanhauser-thc <vh@thc.org>
Date: Fri, 5 Mar 2021 10:05:43 +0100
Subject: fix laf string transform crash

---
 instrumentation/SanitizerCoverageLTO.so.cc | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'instrumentation/SanitizerCoverageLTO.so.cc')

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;
-- 
cgit 1.4.1