fix: accumulate MSG_IO_ERROR in multiplex reader#2441
Merged
Conversation
Add io_error accumulator to MultiplexReader that OR's incoming MSG_IO_ERROR payloads (upstream io.c:1521-1528). Previously these messages were silently discarded in the catch-all arm. Add take_io_error() to both MultiplexReader and ServerReader for the receiver to retrieve and forward accumulated I/O error flags.
oferchen
added a commit
that referenced
this pull request
May 1, 2026
Add io_error accumulator to MultiplexReader that OR's incoming MSG_IO_ERROR payloads (upstream io.c:1521-1528). Previously these messages were silently discarded in the catch-all arm. Add take_io_error() to both MultiplexReader and ServerReader for the receiver to retrieve and forward accumulated I/O error flags.
oferchen
added a commit
that referenced
this pull request
May 5, 2026
Add io_error accumulator to MultiplexReader that OR's incoming MSG_IO_ERROR payloads (upstream io.c:1521-1528). Previously these messages were silently discarded in the catch-all arm. Add take_io_error() to both MultiplexReader and ServerReader for the receiver to retrieve and forward accumulated I/O error flags.
oferchen
added a commit
that referenced
this pull request
May 18, 2026
The vstring codec is exchanged during protocol 30+ capability negotiation, well before authentication completes, making any panic in the reader a pre-auth remote attack surface (FCV-3 audit, PR #4407). Add a libFuzzer target that drives `read_vstring` through the public `negotiate_capabilities` entry point, with a selector byte that fans out across protocol versions and role flags so both the one-byte and two-byte length encodings and the UTF-8 validation path are exercised. Register the new bin in fuzz/Cargo.toml and seed the corpus with a known-good vstring.
oferchen
added a commit
that referenced
this pull request
May 18, 2026
The vstring codec is exchanged during protocol 30+ capability negotiation, well before authentication completes, making any panic in the reader a pre-auth remote attack surface (FCV-3 audit, PR #4407). Add a libFuzzer target that drives `read_vstring` through the public `negotiate_capabilities` entry point, with a selector byte that fans out across protocol versions and role flags so both the one-byte and two-byte length encodings and the UTF-8 validation path are exercised. Register the new bin in fuzz/Cargo.toml and seed the corpus with a known-good vstring.
oferchen
added a commit
that referenced
this pull request
May 18, 2026
The vstring codec is exchanged during protocol 30+ capability negotiation, well before authentication completes, making any panic in the reader a pre-auth remote attack surface (FCV-3 audit, PR #4407). Add a libFuzzer target that drives `read_vstring` through the public `negotiate_capabilities` entry point, with a selector byte that fans out across protocol versions and role flags so both the one-byte and two-byte length encodings and the UTF-8 validation path are exercised. Register the new bin in fuzz/Cargo.toml and seed the corpus with a known-good vstring.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
io_error: i32accumulator toMultiplexReaderthat OR's incomingMSG_IO_ERRORpayloads (upstreamio.c:1521-1528)MSG_IO_ERRORmessages were silently discarded in the catch-all_ =>armtake_io_error()to bothMultiplexReaderandServerReaderfor retrieving accumulated I/O error flagsget_mut()toCompressedReaderfor the compressed variant to delegateCloses #296
Test plan
multiplex_reader_accumulates_msg_io_error- verifies OR accumulation of multiple messagesmultiplex_reader_io_error_wrong_payload_length_ignored- non-4-byte payloads ignoredserver_reader_take_io_error_plain_returns_zero- plain mode returns 0server_reader_take_io_error_multiplex_accumulates- ServerReader wrapper delegatesmsg_io_error_round_trip_through_multiplex_layer- full end-to-end round tripcargo fmtandcargo clippypass clean