Both mesh::Packet::writePath and ::copyPath did a raw memcpy of the
decoded hash_count*hash_size bytes from src to dest with no bound on
src. Two call sites used phone-supplied or LoRa-anon-supplied buffers
where the path_len byte was attacker-controlled:
- CompanionMesh CMD_SEND_CHANNEL_DATA accepted len>=4 and called
writePath with no src bound; a paired phone could leak up to ~65
bytes of syswq stack into the outgoing LoRa channel-data frame.
- RepeaterMesh handleAnonRegionsReq / handleAnonOwnerReq /
handleAnonClockReq read reply_path_len from an unauthenticated
LoRa anon-request payload and called copyPath without any src
bound. Any LoRa neighbor could leak repeater stack into the
reply path.
Hardened the API: both functions now require an explicit src_len
and reject (return 0) when the decoded byte count exceeds it.
Updated all 14 call sites across Packet/Mesh/Dispatcher/BaseChatMesh/
CompanionMesh/RepeaterMesh. Trusted callers (internal MAX_PATH_SIZE
buffers) pass MAX_PATH_SIZE; untrusted callers pass real remaining
length. Added len-5 plumbing through the anon-handler signatures.
CMD_SEND_CHANNEL_DATA also gained a local len>=5 + path_bytes
sanity check for early rejection.
liquidraver