myxce/.wolf/bugs/bug-1430.md
Rongsong Shen d26ff8870d
feat(buglog): one Markdown record per bug, checked against a record standard
The buglog was one 27K-line JSON file whose fields covered only symptom,
root cause and fix, as free text: 2% of entries named the code version a
bug was found on, 12% the build profile, 36% a way to reproduce, and 58% of
the file was OpenWolf hook auto-detections ("Missing guard clause",
"Function not marked async" on .md files).

- .claude/skills/buglog/bug-record.md: the record standard. Eight
  sections (Summary as the title, Description, Environment, Reproduction;
  Root cause, Fix, Verification, References once fixed), each with the
  content it must contain -- e.g. Environment needs the OS, the libc the
  failing binary loads (from its ELF interpreter: glibc 2.42 in the nix
  shell vs 2.40 on the host), toolchain, build profile and commit.
- .wolf/bugs/<id>.md: 500 records migrated from buglog.json; every field
  verified to round-trip. They carry legacy: true and an explicit "not
  recorded" where the old log had no such field; component derived from
  file paths, severity from keywords (else unknown), fix_commits from
  hashes in status_note/fix that git resolves (91 of 463 fixed).
- .wolf/buglog-archive.json: the 710 hook auto-detections, verbatim.
- .wolf/buglog.json is now an index generated from the records, keeping
  the fields OpenWolf's hooks and `openwolf bug search` read.
- scripts/buglog.py rewritten: new (template + Environment collected from
  the machine and --binary), check, status (refuses a status the record
  doesn't support; fixed needs Root cause, Fix, Verification and
  --commit hashes git resolves), note, recur, set, show, list, triage,
  env, index. 29 unittest cases in scripts/tests/test_buglog.py.
- scripts/git-hooks/pre-commit runs `check --staged`: incomplete staged
  records, a legacy record hand-changed to fixed without the fix-time
  sections, a new record claiming legacy: true, or a stale index refuse
  the commit.
- scripts/gitea-sync.py reads the records: issue body = the record's
  sections plus linked fix commits (origin remote, GITEA_COMMIT_REPO to
  override), and a body hash so an issue's text is refreshed when the
  record changes.
- bug-1866 rewritten to the full standard as the worked example.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-09-28 03:40:11 +00:00

38 lines
2.4 KiB
Markdown

---
id: "bug-1430"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "controller"
severity: "crash"
timestamp: "2026-07-10T07:12:00Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 2
files: ["src/controller/ha.c"]
tags: ["asan", "use-after-free", "prevote", "delaymgr", "chaotic-soak", "raft"]
related: ["bug-1423", "bug-1424"]
legacy: true
---
# bug-1430: AddressSanitizer: heap-use-after-free on address ... WRITE of size 4 ... #0…
## Description
AddressSanitizer: heap-use-after-free on address ... WRITE of size 4 ... #0 ha_prevote_cancel_round_timeout ../controller/ha.c:6712 #1 ha_start_prevote_async ../controller/ha.c:6889 #2 ha_failover_stagger_fn ../controller/ha.c:7259 -- crashed 2 of 3 nodes during a live chaotic HA soak (10-round overlapping-kill mode)
## Environment
_Not recorded (migrated from buglog.json)._
## Reproduction
_Not recorded (migrated from buglog.json)._
## Root cause
ha_prevote_round_timeout_fn (the delaymgr task body for a PreVote round's timeout) only cleared the static s_prevote_round_ctx pointer inside its 'round still in progress' branch (ha->raft.pre_vote_in_progress true). When a round instead got decided via a reply arriving through raft_on_pre_vote_reply (which clears pre_vote_in_progress without touching s_prevote_round_ctx) and the round-timeout task fired afterward anyway (a benign, expected race), the function fell straight through to free(ctx) with s_prevote_round_ctx still pointing at that about-to-be-freed memory. The next PreVote round's ha_start_prevote_async defensively calls ha_prevote_cancel_round_timeout() before arming its own timer, reading the dangling pointer and writing to old->cancelled -- UAF. Same call stack (single delaymgr thread T8) on both crashing nodes, all-100%-reproducible under chaotic-mode's rapid overlapping restarts.
## Fix
ha_prevote_round_timeout_fn now does a CAS (atomic_compare_exchange_strong_explicit matching s_prevote_round_ctx against this specific ctx, clearing to NULL) UNCONDITIONALLY as the first action, before either branch -- so the static pointer is never left dangling regardless of which path is taken. Brings it in line with the already-correct pattern used by the sibling function raft_election_timeout_fn (same file), which unconditionally clears its own stored ctx pointer before checking cancelled.
## Verification
_Not recorded (migrated from buglog.json)._
## References
- Related: bug-1423, bug-1424