# Expected Diagnosis: O11Y-2298309

## Root Cause

TiDB v8.5.2 known bug (GitHub Issue #63956): KILL QUERY on an idle transaction triggers a panic in `memory.(*Tracker).Consume()` during transaction rollback cleanup. The memory tracker attempts to update statistics on an already-terminated session, causing the process to crash.

## Key Evidence

1. **Panic stack trace** from db-tidb-60 logs:
   - `panic: [executor:1317]Query execution was interrupted`
   - Stack: `memory.(*Tracker).Consume -> LazyTxn.cleanup -> clientConn.Close`

2. **KILL command** from remote TiDB instance (10.250.159.158) targeting conn=2107655910

3. **GitHub Issue #63956**: exact same panic signature, confirmed as `severity/major`

4. **Fix PRs**:
   - PR #63992: recover panic during clientConn Close (merged 2025-10-16)
   - PR #64001: reset memory hook before rollback (merged 2025-10-29)
   - Both cherry-picked to release-8.5 in Nov/Dec 2025

5. **Version gap**: v8.5.2 released 2025-06-04, predates both fixes

## Expected Recommendation

Upgrade to v8.5.3 or later which includes both fix cherry-picks.