fix(carbonio): validate machoNet oob length against payload size#15
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Rakdos8 wants to merge 1 commit into
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fix(carbonio): validate machoNet oob length against payload size#15Rakdos8 wants to merge 1 commit into
Rakdos8 wants to merge 1 commit into
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A hostile peer controls m_oobDataLen via the packet's out-of-band length prefix. It was only bounded by maxPacketSize, never by the payload actually received, so m_payload could be advanced past m_data, payloadLen() - m_oobDataLen could underflow, and adjacent heap memory was disclosed to the oob callbacks. Reject packets whose oob block plus its length prefix exceeds payloadLen().
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Summary
Closes a network-reachable heap over-read in the machoNet stream packet parser.
Problem
m_oobDataLenis read from the wire (attacker-controlled out-of-band lengthprefix). It was only bounded by
maxPacketSize, never by the payload actuallyreceived. A hostile peer could announce an
m_oobDataLenlarger than thereceived buffer, causing
m_payloadto advance pastm_data, thepayloadLen() - m_oobDataLencomputation to underflow, and adjacent heapmemory to be handed to the oob callbacks / returned to Python.
Fix
After the existing
maxPacketSizeguard, reject any packet whose oob blockplus its 4-byte length prefix exceeds
payloadLen(). Same style as thesibling check (PyErr_Format + return false), no behavioural change for
well-formed packets.
Type
Security — remote heap over-read / information disclosure (Critical).
Testing
Manual review; behaviour for valid packets unchanged (guard only rejects
malformed oversized oob lengths).