ctx->reply.u is a single untagged union shared across opcodes (debugmsg /
get(dataset_t*) / jobid / clusterconf / ctrlstatus alias the same 8 bytes).
Commit 61e1391 added speculative free-guards
`if (ctx->reply.u.ctrlstatus) free_CtrlStatus_ptr(...)` (and the clusterconf
twin). A non-NULL slot does NOT imply a CtrlStatus*: a failover-aborted
reslist/joblist leaves ctx->reply.u.get == &getreply (a dead STACK pointer)
because xce_get_with_condition/xce_resval only cleared the slot on the success
path, not the xce_get_req<0 / cbuf_get<0 early returns. The next ctrlstatus
reply (worker thread) freed that foreign pointer as a CtrlStatus -> ASan
SEGV / stack-use-after-return in free_CtrlStatus (controller.capnp.c:11638).
Fix (root cause, both layers):
- Revert the unsafe free-guards in xce_handle_reply: MOVE_PTR overwrite only,
never free/deref an untagged union slot by type.
- Clear ctx->reply.u.get = NULL on ALL exit paths of xce_get_with_condition
and xce_resval via a single `goto done` cleanup (forget-proof; the bug was
one forgotten failover path). Also drops the now-unused controller.capnp.h.
- Defense-in-depth: handle_get_reply drops a reply when the slot is NULL.
Regression: expose xce_handle_reply and add
test_handle_reply_ctrlstatus_does_not_free_foreign_slot, which poisons the
shared slot with a foreign heap value and proves the ctrlstatus reply handler
does not free it (RED reproduced the exact free_CtrlStatus_ptr double-free;
GREEN after fix). xcelib_test 244/0, controller_unit_test 166/0, all binaries
build clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MSxwb2Xt5F84ATgiAZnH8V
Add the full call chain for host control operations from the Go API
server through the C library to the controller:
- schema/controller.capnp: HostControl struct + hostctrlmsg @21
in Request.body union
- include/typemap.h: xce_hostctrl_t* hostctrlmsg in body union
(placed after @20 clrpreasonmsg, matching capnp ordinal)
- include/client.h, xceapi.h, request.h: declarations for
xcecli_hostctrl, xce_hostctrl, xce_hostctrl_req
- lib/client.c: xcecli_hostctrl (validate + delegate to xce_hostctrl)
- lib/xceapi.c: xce_hostctrl (validate ctx state + send + wait reply)
- lib/request.c: xce_hostctrl_req (validate hostname/empty/nil,
accept only HOST_OPEN/HOST_CLOSE, reject HOST_TAG/UNTAG)
- lib/helper.c: Request_body_hostctrlmsg cases in
xce_request_body() and xce_request_msg_name()
- controller/cluster.c: OPCode_hostcontrol dispatch
- controller/include/cluster.h: do_hostcontrol_op declaration
- controller/worker.c: do_hostcontrol_op + fix pre-existing
goto-clean bug in worker_ctrl that leaked write lock and
reference on HOST_OPEN/HOST_CLOSE no-op paths
TDD: 8 xce_hostctrl_req validation tests (null ep, null ctrl,
null/empty hostname, HOST_DO_NONE no-op, HOST_TAG/UNTAG reject,
negative action reject, HOST_OPEN/CLOSE accept via xce_request).
116/116 xcelib tests pass. CGO_ENABLED=0 Go backend tests pass.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Fix issue to xce_get() api cause client side crash
- add parse resreq section
- add rusage parser
- parse resreq with basic support alternative & compound, still miss select
