Add read lock to Service.MarshalJSON to prevent data race during state save#189
Open
AnyCPU wants to merge 1 commit intobasecamp:mainfrom
Open
Add read lock to Service.MarshalJSON to prevent data race during state save#189AnyCPU wants to merge 1 commit intobasecamp:mainfrom
AnyCPU wants to merge 1 commit intobasecamp:mainfrom
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
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
MarshalJSON in internal/server/service.go reads s.active, s.rollout, s.rolloutController, s.options, and s.targetOptions without acquiring s.serviceLock. These fields are modified under the lock by UpdateLoadBalancer, SetRolloutSplit, and StopRollout. Since MarshalJSON is called from saveStateSnapshot during live operation (on every deploy, remove, pause, resume, rollout), a concurrent RPC can race with the state save, potentially causing a nil pointer dereference, corrupted output, or silently wrong state persisted to disk.
Fix
Add s.serviceLock.RLock() / defer s.serviceLock.RUnlock() at the top of MarshalJSON. The matching UnmarshalJSON does not need a lock — it is only called during startup via RestoreLastSavedState, before the server accepts connections.