channeld: initialize tx_sigs_allowed on startup - #9483
Open
erickcestari wants to merge 1 commit into
Open
Conversation
peer->tx_sigs_allowed was only set in peer_reconnect() and when we receive channel_ready, so on a fresh channeld start a stray tx_signatures arriving before the peer's channel_ready made handle_unexpected_tx_sigs() read an uninitialized bool. UBSan flags this as a load of an invalid bool value, and in normal builds the "warn and disconnect" branch was effectively taken at random. Default it to false: we only allow an unexpected tx_signatures when reconnecting. Changelog-None
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
peer->tx_sigs_allowedwas only set inpeer_reconnect()and when we receivechannel_ready, so on a fresh channeld start a straytx_signaturesarriving before the peer'schannel_readymadehandle_unexpected_tx_sigs() read an uninitializedbool.UBSanflags this as a load of an invalid bool value, and in normal builds the "warn and disconnect" branch was effectively taken at random.Default it to false: we only allow an unexpected
tx_signatureswhen reconnecting.Changelog-None
I've found this issue using Smite.
The Impact is minimal: the flag only decides whether one unexpected
tx_signaturesis logged and dropped, or answered with a warning and a disconnect. The message is never acted on either way, so no channel state or funds are affected; the worst case is that a peer gets one stray message ignored instead of being disconnected.