[budget] partially fixing a race condition that could cause a good peer to be banned #2395
Conversation
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
… being banned. Moved TRY_LOCK to LOCK to perform the budget maps check every 14 blocks without exception. If peers doesn't perform the validation and update proposals, votes and budget finalization maps at the same network time, then there could be a peer sending votes that aren't longer valid and end up being banned.
Fuzzbawls
approved these changes
May 20, 2021
furszy
referenced
this pull request
in furszy/bitcoin-core
Jun 18, 2021
… being banned. Moved TRY_LOCK to LOCK to perform the budget maps check every 14 blocks without exception. If peers doesn't perform the validation and update proposals, votes and budget finalization maps at the same network time, then there could be a peer sending votes that aren't longer valid and end up being banned. Github-Pull: bitcoin#2395 Rebased-From: 7faa5e9
furszy
added a commit
that referenced
this pull request
Jun 19, 2021
3344fb3 [CI] Remove Ubuntu 16.04 from GA workflow, has been deprecated by GA and will be removed on September 20, 2021. (furszy) b5a8638 [GUI] Cleanup compiler warnings in qtutils.h/cpp (furszy) 73b56e9 [GUI] Fix invisible text due an invalid transparent selection color. (furszy) df5d820 budget: fixing a possible race condition that could cause a good peer being banned. (furszy) a5fd073 Fix minimize and close bugs (furszy) b516e36 depends: update Qt 5.9 source url (Kittywhiskers Van Gogh) 18f4b4a BugFix: fix not updating GUI balance race condition. (furszy) 2c923ed scripted-diff: Replace 'NULL' with 'nullptr' in guiutil.cpp (random-zebra) 7b8b23a Fix memory leaks in qt/guiutil.cpp (Dan Raviv) cbd5c78 Add search option to My Addresses list in receive widget (Volodia) 0dcbea2 [build] depends macOS: point --sysroot to SDK (Sjors Provoost) 3b542fc [Doc] remove old gitian keys. (furszy) 0f099e8 [GUI] Generate FAQ answer content programmatically (Fuzzbawls) 8483861 qt:Show the entire Window when double clicking on taskbar (ken2812221) 998c7e8 [GUI] fix QT 5.15 `currentIndexChanged(QString)` deprecated method call. (furszy) Pull request description: List of straightforward PRs back ported from v6.0 into the v5.2 branch (ordered by merge date). * #2259. * #2260. * #2348 * #2350 * #2353 * #2305 * #2374 * #2379 * #2384 * #2377 * #2395 * #2401 * #2413 ACKs for top commit: random-zebra: utACK 3344fb3 Fuzzbawls: utACK 3344fb3 Tree-SHA512: 4317e83d4c1228b8ae20dc1bc5c8e43ac87598d4d9d9244fdd032f2a0c5eccd1a7ed27bc29094c7411dd653b187c728ab31d732ea686abda15228920a390e4e1
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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.
Moved
TRY_LOCKtoLOCKto perform the budget maps check every 14 blocks without exception. If peers doesn't perform the validation and update proposals, votes and budget finalization maps at a similar network time, there could be a peer sending votes that aren't longer valid and end up being banned.This is just an initial small mitigation, have seen peers banning other peers for this race condition. This area needs a further rework later on.
Budget data is being validated on every new arriving block while the masternodes status is being checked and updated every 5 seconds (which is way too fast and not needed but that is another topic). The budget data update should be done right after the masternode removal/invalidation, so the peer updates the budget maps and does not send the invalid data to the network (important note: better to do this rather than force a budget data check and update on every peer sync request).
Plus will probably work in another PR in decoupling the called "masternodeds thread" into its proper file and update budget data from it as well (solving some cyclic dependencies in the way).
-- This is something to have in mind for DMN and the future PoSe too. The budget maps check and update should be done right after the masternode removal/invalidation and not at different times --