daemon: parse apid/ctid in dlt_daemon_control_set_log_level_v2#864
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daemon: parse apid/ctid in dlt_daemon_control_set_log_level_v2#864SoundMatt wants to merge 1 commit into
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The function never assigned req.apid or req.ctid, so the SET_LOG_LEVEL
V2 control handler never actually parsed the apid/ctid fields out of
the message. The two pre-existing dlt_set_id_v2() calls (filling
req.apid / req.ctid, then filling local apid / ctid from req) were
no-ops because:
- req is zero-initialised (DltServiceSetLogLevelV2 req = {0};), so
req.apid and req.ctid (declared as char * in the struct) start NULL.
- dlt_set_id_v2 early-returns when its destination id is NULL.
Consequences:
- Requests with apidlen = ctidlen = 0 fell through to the else branch
with apid = ctid = NULL, silently no-op'ing.
- Requests with apidlen != 0 dereferenced the still-NULL local apid at
the wildcard / "field-only" branches (apid[apid_length - 1]),
crashing the daemon. Reachable from any client that can speak to the
control socket.
Fix: when each length field is non-zero, point req.apid / req.ctid
directly into msg->databuffer (lifetime is bounded by this function's
stack frame). Then assign the local apid / ctid via plain pointer
assignment so the existing wildcard / field-only branch logic (which
keys off apid == NULL / ctid == NULL) operates on real values.
Closes COVESA#863.
This was referenced May 5, 2026
SoundMatt
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May 5, 2026
Companion fix to the OOB-read fix in this same commit series. The function never assigned req->apid or req->ctid: req is calloc'd, so the char * pointer fields start NULL, and the dlt_set_id_v2(req->apid, ...) call to populate them was a no-op (dlt_set_id_v2 early-returns when its destination is NULL). req->apid / req->ctid stayed NULL and were then passed to dlt_daemon_application_find_v2 and dlt_daemon_context_find_v2 despite req->apidlen / req->ctidlen being non-zero — every non-empty lookup was silently turned into a zero-length one. Replace the no-op dlt_set_id_v2 calls with conditional pointer assignments into msg->databuffer, mirroring the surgical approach taken for set_log_level_v2 in PR COVESA#864 and unregister_context_v2 in PR COVESA#868. The bounds checks added in the previous commit ensure the pointer-into-databuffer assignments are safe. Closes COVESA#870. Related: COVESA#866.
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Problem
dlt_daemon_control_set_log_level_v2never actually parsed theapid/ctidfields out of incoming SET_LOG_LEVEL V2 requests:req.apid/req.ctid(declaredchar *inDltServiceSetLogLevelV2) are zero-initialised to NULL.dlt_set_id_v2()calls intended to populate them wereno-ops because
dlt_set_id_v2early-returns when its destination isNULL.
dereferences the still-NULL local
apid/ctid(
apid[apid_length - 1]etc.) when their length is non-zero,crashing the daemon.
Reachable from any client that can talk to the control socket
(dispatched from
dlt_daemon_handle_control_messages_v2).Full analysis in #863.
Fix
When each length field is non-zero, point
req.apid/req.ctiddirectly into
msg->databuffer. Then assign the localapid/ctidpointers via plain assignment so the existing branch logic (which keys
off
apid == NULL/ctid == NULL) operates on real values.reqshares storage with the message buffer only for the duration ofthis function call, so the pointer-into-databuffer trick is lifetime-
safe.
Notes
function): they touch overlapping lines but not in conflicting
ways. Whichever lands first, the other rebases trivially.
end-to-end with a live daemon and crafted control messages. Happy to
add one if maintainers can point me at the right harness.
Closes #863.