The libFuzzer harness was compiled without CONFIG_CSI_FRAME_HE_TAGGING,
so the new byte 18/19 path in csi_collector.c was zero-filled at compile
time and never fuzzed. Three changes to fix that:
1. test/stubs/esp_stubs.h: wifi_pkt_rx_ctrl_t gains both branch families
- HE branch (CONFIG_SOC_WIFI_HE_SUPPORT path): cur_bb_format, second
- Legacy branch (S3 / pre-HE chips): sig_mode, cwb, stbc
A single stub compiles for either branch; the Makefile picks which
one is active via -D flags. Both sets are declared so a build for
the unselected branch still compiles cleanly.
2. test/Makefile: CFLAGS now defines CONFIG_CSI_FRAME_HE_TAGGING=1 so
the new code path is reachable. CONFIG_SOC_WIFI_HE_SUPPORT stays
UNSET (default — exercises the legacy S3 branch). Add it to CFLAGS
for a parallel HE-stub run if you want coverage of the C6 branch.
3. test/fuzz_csi_serialize.c: parses 3 more control bytes from fuzz
input (he_inputs[2] + legacy_inputs) and writes them through
info.rx_ctrl.{cur_bb_format,second,sig_mode,cwb,stbc} so the
serializer's PpduType switch and Adr018Flags computation are
reached on every iteration.
Result: the existing libFuzzer corpus + ASAN/UBSAN now covers the
ADR-110 wire encoding paths on every run. No more zero-fill silent skip.
Co-Authored-By: claude-flow <ruv@ruv.net>