From bb1f5e7687799b6650e6b03b285576d9c72dc7d0 Mon Sep 17 00:00:00 2001 From: Craig Tiller Date: Thu, 1 Aug 2024 13:02:40 -0700 Subject: [PATCH] [v1.62] [chttp2] Fix a bug in hpack error handling (#37363) PiperOrigin-RevId: 657234128 PiperOrigin-RevId: 658458047 CVE: CVE-2024-7246 Upstream-Status: Backport [https://github.com/grpc/grpc/commit/1d172cfca56440889ca32ae516b8c2767321f5b5] Backport Changes: - The following files were omitted as they are not present in the current version: test/core/transport/chttp2/hpack_parser_test.cc, introduced in v1.8.0-pre2 by https://github.com/grpc/grpc/commit/34a57d0346afe95e11104462c30dc468b0cb0b89 test/core/transport/chttp2/hpack_sync_fuzzer.cc and test/core/transport/chttp2/hpack_sync_fuzzer.proto, introduced in v1.56.0-pre1 by https://github.com/grpc/grpc/commit/65a2a895afaf1d2072447b9baf246374b182a946 (cherry picked from commit 1d172cfca56440889ca32ae516b8c2767321f5b5) Signed-off-by: Sudhir Dumbhare --- .../chttp2/transport/hpack_parser.cc | 63 +++++++++++-------- .../transport/chttp2/transport/hpack_parser.h | 2 + 2 files changed, 38 insertions(+), 27 deletions(-) diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.cc b/src/core/ext/transport/chttp2/transport/hpack_parser.cc index 31bf46456f..f2fe80c504 100644 --- a/src/core/ext/transport/chttp2/transport/hpack_parser.cc +++ b/src/core/ext/transport/chttp2/transport/hpack_parser.cc @@ -91,12 +91,14 @@ constexpr Base64InverseTable kBase64InverseTable; class HPackParser::Input { public: Input(grpc_slice_refcount* current_slice_refcount, const uint8_t* begin, - const uint8_t* end, absl::BitGenRef bitsrc, HpackParseResult& error) + const uint8_t* end, absl::BitGenRef bitsrc, + HpackParseResult& frame_error, HpackParseResult& field_error) : current_slice_refcount_(current_slice_refcount), begin_(begin), end_(end), frontier_(begin), - error_(error), + frame_error_(frame_error), + field_error_(field_error), bitsrc_(bitsrc) {} // If input is backed by a slice, retrieve its refcount. If not, return @@ -215,14 +217,18 @@ class HPackParser::Input { // Check if we saw an EOF bool eof_error() const { - return min_progress_size_ != 0 || error_.connection_error(); + return min_progress_size_ != 0 || frame_error_.connection_error(); + } + + // Reset the field error to be ok + void ClearFieldError() { + if (field_error_.ok()) return; + field_error_ = HpackParseResult(); } // Minimum number of bytes to unstuck the current parse size_t min_progress_size() const { return min_progress_size_; } - bool has_error() const { return !error_.ok(); } - // Set the current error - tweaks the error to include a stream id so that // chttp2 does not close the connection. // Intended for errors that are specific to a stream and recoverable. @@ -246,10 +252,7 @@ class HPackParser::Input { // read prior to being able to get further in this parse. void UnexpectedEOF(size_t min_progress_size) { GPR_ASSERT(min_progress_size > 0); - if (min_progress_size_ != 0 || error_.connection_error()) { - GPR_DEBUG_ASSERT(eof_error()); - return; - } + if (eof_error()) return; // Set min progress size, taking into account bytes parsed already but not // consumed. min_progress_size_ = min_progress_size + (begin_ - frontier_); @@ -302,13 +305,18 @@ class HPackParser::Input { // Do not use this directly, instead use SetErrorAndContinueParsing or // SetErrorAndStopParsing. void SetError(HpackParseResult error) { - if (!error_.ok() || min_progress_size_ > 0) { - if (error.connection_error() && !error_.connection_error()) { - error_ = std::move(error); // connection errors dominate + SetErrorFor(frame_error_, error); + SetErrorFor(field_error_, std::move(error)); + } + + void SetErrorFor(HpackParseResult& error, HpackParseResult new_error) { + if (!error.ok() || min_progress_size_ > 0) { + if (new_error.connection_error() && !error.connection_error()) { + error = std::move(new_error); // connection errors dominate } return; } - error_ = std::move(error); + error = std::move(new_error); } // Refcount if we are backed by a slice @@ -320,7 +328,8 @@ class HPackParser::Input { // Frontier denotes the first byte past successfully processed input const uint8_t* frontier_; // Current error - HpackParseResult& error_; + HpackParseResult& frame_error_; + HpackParseResult& field_error_; // If the error was EOF, we flag it here by noting how many more bytes would // be needed to make progress size_t min_progress_size_ = 0; @@ -597,6 +606,7 @@ class HPackParser::Parser { bool ParseTop() { GPR_DEBUG_ASSERT(state_.parse_state == ParseState::kTop); auto cur = *input_->Next(); + input_->ClearFieldError(); switch (cur >> 4) { // Literal header not indexed - First byte format: 0000xxxx // Literal header never indexed - First byte format: 0001xxxx @@ -702,7 +712,7 @@ class HPackParser::Parser { break; } gpr_log( - GPR_DEBUG, "HTTP:%d:%s:%s: %s%s", log_info_.stream_id, type, + GPR_INFO, "HTTP:%d:%s:%s: %s%s", log_info_.stream_id, type, log_info_.is_client ? "CLI" : "SVR", memento.md.DebugString().c_str(), memento.parse_status == nullptr ? "" @@ -951,11 +961,10 @@ class HPackParser::Parser { state_.string_length) : String::Parse(input_, state_.is_string_huff_compressed, state_.string_length); - HpackParseResult& status = state_.frame_error; absl::string_view key_string; if (auto* s = absl::get_if(&state_.key)) { key_string = s->as_string_view(); - if (status.ok()) { + if (state_.field_error.ok()) { auto r = ValidateKey(key_string); if (r != ValidateMetadataResult::kOk) { input_->SetErrorAndContinueParsing( @@ -965,7 +974,7 @@ class HPackParser::Parser { } else { const auto* memento = absl::get(state_.key); key_string = memento->md.key(); - if (status.ok() && memento->parse_status != nullptr) { + if (state_.field_error.ok() && memento->parse_status != nullptr) { input_->SetErrorAndContinueParsing(*memento->parse_status); } } @@ -992,16 +1001,16 @@ class HPackParser::Parser { key_string.size() + value.wire_size + hpack_constants::kEntryOverhead; auto md = grpc_metadata_batch::Parse( key_string, std::move(value_slice), state_.add_to_table, transport_size, - [key_string, &status, this](absl::string_view message, const Slice&) { - if (!status.ok()) return; + [key_string, this](absl::string_view message, const Slice&) { + if (!state_.field_error.ok()) return; input_->SetErrorAndContinueParsing( HpackParseResult::MetadataParseError(key_string)); gpr_log(GPR_ERROR, "Error parsing '%s' metadata: %s", std::string(key_string).c_str(), std::string(message).c_str()); }); - HPackTable::Memento memento{std::move(md), - status.PersistentStreamErrorOrNullptr()}; + HPackTable::Memento memento{ + std::move(md), state_.field_error.PersistentStreamErrorOrNullptr()}; input_->UpdateFrontier(); state_.parse_state = ParseState::kTop; if (state_.add_to_table) { @@ -1163,13 +1172,13 @@ grpc_error_handle HPackParser::Parse( std::vector buffer = std::move(unparsed_bytes_); return ParseInput( Input(nullptr, buffer.data(), buffer.data() + buffer.size(), bitsrc, - state_.frame_error), + state_.frame_error, state_.field_error), is_last, call_tracer); } - return ParseInput( - Input(slice.refcount, GRPC_SLICE_START_PTR(slice), - GRPC_SLICE_END_PTR(slice), bitsrc, state_.frame_error), - is_last, call_tracer); + return ParseInput(Input(slice.refcount, GRPC_SLICE_START_PTR(slice), + GRPC_SLICE_END_PTR(slice), bitsrc, state_.frame_error, + state_.field_error), + is_last, call_tracer); } grpc_error_handle HPackParser::ParseInput( diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.h b/src/core/ext/transport/chttp2/transport/hpack_parser.h index 5edb34b960..f7002186f7 100644 --- a/src/core/ext/transport/chttp2/transport/hpack_parser.h +++ b/src/core/ext/transport/chttp2/transport/hpack_parser.h @@ -238,6 +238,8 @@ class HPackParser { HPackTable hpack_table; // Error so far for this frame (set by class Input) HpackParseResult frame_error; + // Error so far for this field (set by class Input) + HpackParseResult field_error; // Length of frame so far. uint32_t frame_length = 0; // Length of the string being parsed