Avoid truncation error on 32 bit platforms.
This is so that truncation warning can be turned into compiler errors for Blink
on 32-bit Android platforms. See https://crbug.com/916990 for more context.
gfe-relnote: No functional change on 64-bit platforms. Not flag protected.
PiperOrigin-RevId: 227019741
Change-Id: I79ca3745e4a1919f5c97e9f0dc61bbd5bc75e677
diff --git a/http2/hpack/decoder/hpack_string_decoder.h b/http2/hpack/decoder/hpack_string_decoder.h
index 8ec0169..88b1add 100644
--- a/http2/hpack/decoder/hpack_string_decoder.h
+++ b/http2/hpack/decoder/hpack_string_decoder.h
@@ -13,6 +13,7 @@
#include <algorithm>
#include <cstdint>
+#include <limits>
#include "base/logging.h"
#include "base/macros.h"
@@ -168,7 +169,18 @@
// false otherwise, in which case status set.
template <class Listener>
void OnStringStart(Listener* cb, DecodeStatus* status) {
- remaining_ = length_decoder_.value();
+ // HpackVarintDecoder::value() returns uint64_t.
+ const uint64_t value = length_decoder_.value();
+ // |remaining_| is size_t. Check for truncation on 32-bit platforms.
+ // numeric_limits::max() is constexpr. On platforms where size_t is at
+ // least 64 bit wide, the compiler optimizes away this branch.
+ if (std::numeric_limits<uint64_t>::max() >
+ std::numeric_limits<size_t>::max() &&
+ value > std::numeric_limits<size_t>::max()) {
+ *status = DecodeStatus::kDecodeError;
+ return;
+ }
+ remaining_ = static_cast<size_t>(value);
// Make callback so consumer knows what is coming.
cb->OnStringStart(huffman_encoded_, remaining_);
}
