myxce/.wolf/bugs/bug-1442.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

4.1 KiB

id status status_updated status_note component severity timestamp last_seen occurrences files tags related legacy
bug-1442 fixed 2026-09-24 apiserver crash 2026-07-15T09:50:00Z 2026-09-19T09:00:00Z 1
src/frontend/apiserver/backend/wire_dispatch_support.go
cgo
wire_dispatch
asan
double-free
use-after-free
job-array-single-wal-record
test-backend
go_push_handler
free_Dataset
free_Dataset_ptr
bug-1441
true

bug-1442: AddressSanitizer: attempting double-free on 0x...1b0 in thread T0 -- fires immediately on…

Description

AddressSanitizer: attempting double-free on 0x...1b0 in thread T0 -- fires immediately on TestWireDispatch_OnePushProducesNRecordsAndLogsOnce, aborts the whole backend.test binary before it can print PASS/FAIL, so TestWireDispatch_RedeliveryCreatesNoNewRecordsAndLogsNothing never runs at all

Environment

Not recorded (migrated from buglog.json).

Reproduction

Not recorded (migrated from buglog.json).

Root cause

NOT ROOT-CAUSED (build/run/report only, no fix attempted per user instruction). bug-1441 (C.go_push_handler cross-file cgo resolution) is now fixed, and a separate missing import "apiserver/store" in wire_dispatch_test.go was fixed as a trivial compile error, so the build now succeeds and the test actually runs -- and immediately hits a real ASan double-free at runtime, not a build failure. Leading hypothesis (unverified): wireDispatchDeliver() (lines 122-180) calls go_push_handler(&decoded, nil) at line 164, whose defer C.free_Request(req) (clib.go) frees *decoded including its Request_body_datamsg payload -- the comment at lines 166-172 asserts free_Dataset() is 'a documented no-op for every table' (citing task 5.3b's residual-gap note) and therefore safe for wireDispatchDeliver to ALSO free ds.rows via free_JobSubmit_ptr() and ds itself at lines 173-177. A 16-byte double-free immediately after go_push_handler returns is consistent with that no-op assumption being wrong for the Data_data_jobArray-derived dataset table specifically (i.e. free_Dataset() actually does free ds->rows or ds itself for this table, and wire_dispatch_support.go's explicit cleanup then frees the same memory again). NOT CONFIRMED -- needs a symbolized ASan backtrace (frames are bare hex addresses in this build) or manual trace of free_Dataset()/free_Request() to confirm which free is the duplicate.

Fix

FIXED and VERIFIED 2026-07-15T09:55:00Z. Root cause confirmed: go_push_handler's internal defer C.free_Request(req) (clib.go) calls free_Request(&decoded), whose Request_body_datamsg case calls free_Dataset_ptr(&decoded.body.datamsg) -- free_Dataset_ptr() (controller.capnp.c, generated) unconditionally free()s the dataset_t container pointer it is given, even though free_Dataset() itself is an empty no-op (never touches ->rows). So ds becomes a dangling pointer the instant go_push_handler returns -- the earlier NOT-ROOT-CAUSED hypothesis was correct in spirit but had the wrong culprit function (free_Dataset_ptr, not free_Dataset). wireDispatchDeliver() (wire_dispatch_support.go) had two bugs: (1) read ds.rows AFTER calling go_push_handler = use-after-free, (2) separately called C.free(ds) again = double-free on the same 16-byte region ASan caught. Fix: capture rows := ds.rows BEFORE calling go_push_handler (line 175), use that captured value afterward instead of re-reading ds.rows, and removed the redundant C.free(unsafe.Pointer(ds)) call entirely since go_push_handler's internal free_Request already frees it. Verified via full ASan CGO rebuild (make test-backend under nix develop ./src with CGO_CFLAGS/CGO_LDFLAGS = -fsanitize=address -g -DWITH_DEBUG=1 + pkg-config librtti/c-capnproto/openssl/tinylog): TestWireDispatch_OnePushProducesNRecordsAndLogsOnce and TestWireDispatch_RedeliveryCreatesNoNewRecordsAndLogsNothing both PASS with zero ASan errors; full ./backend/... suite (91 subtests, convert/handler/heartbeat/peers/wire_dispatch/auth) all PASS, zero regressions; make test (CGO_ENABLED=0) also fully green.

Verification

Not recorded (migrated from buglog.json).

References

  • Related: bug-1441