Check that data_ is non-null before memcpy in EnsureCapacityWithHeadroom
Since we've passed IsConsistent(), if data_ is null, size_ must be
zero, so we might attempt to copy zero bytes from a nullptr. This does
not seem to cause problems in practice, but is still undefined
behaviour. This was caught on an UBsan test run in Firefox.
Bug: webrtc:11613
Change-Id: Iad795bf19ed69b56e066958a54a7e3a434b996cf
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176280
Commit-Queue: Dan Minor <dminor@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31386}
diff --git a/rtc_base/buffer.h b/rtc_base/buffer.h
index 3048b91..d1639e2 100644
--- a/rtc_base/buffer.h
+++ b/rtc_base/buffer.h
@@ -370,7 +370,9 @@
: capacity;
std::unique_ptr<T[]> new_data(new T[new_capacity]);
- std::memcpy(new_data.get(), data_.get(), size_ * sizeof(T));
+ if (data_ != nullptr) {
+ std::memcpy(new_data.get(), data_.get(), size_ * sizeof(T));
+ }
MaybeZeroCompleteBuffer();
data_ = std::move(new_data);
capacity_ = new_capacity;
