pw_protobuf: Fix undefined pointer deref in fuzz test

The encoder fuzz test can sometimes attempt to dereference an undefined pointer to get its address, which is technically undefined behavior. This fixes that occurance. Change-Id: If67d58835ebc7a85813d60b6062ec88aab0e18c8 Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/188281 Reviewed-by: Aaron Green <[email protected]> Pigweed-Auto-Submit: Armando Montanez <[email protected]> Presubmit-Verified: CQ Bot Account <[email protected]> Commit-Queue: Auto-Submit <[email protected]>
pauschar · Jan 18, 2024 · 43ce442 · 43ce442
1 parent fd1e0b7
commit 43ce442
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/pw_protobuf/encoder_fuzzer.cc b/pw_protobuf/encoder_fuzzer.cc
@@ -77,6 +77,9 @@ const char* ConsumeString(FuzzedDataProvider& provider,
 span<const std::byte> ConsumeBytes(FuzzedDataProvider& provider,
                                    std::vector<std::byte>* data) {
   size_t num = ConsumeSize<std::byte>(provider);
+  if (num == 0) {
+    return span<const std::byte>();
+  }
   auto added = provider.ConsumeBytes<std::byte>(num);
   size_t off = data->size();
   num = added.size();