bounds-check OnUserControlMessage like sibling control handlers#3329
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sahvx655-wq wants to merge 1 commit into
Open
bounds-check OnUserControlMessage like sibling control handlers#3329sahvx655-wq wants to merge 1 commit into
sahvx655-wq wants to merge 1 commit into
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Pull request overview
This PR hardens RTMP control-message parsing by adding a lower-bound length check to RtmpChunkStream::OnUserControlMessage, aligning it with sibling control handlers and preventing out-of-bounds reads / unsigned underflow when the message body is shorter than the 2-byte event type.
Changes:
- Reject user control messages with
message_length < 2(and keep the existing upper bound of 32). - Improve the error log to report the invalid length value.
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| const RtmpMessageHeader& mh, butil::IOBuf* msg_body, Socket* socket) { | ||
| if (mh.message_length > 32) { | ||
| RTMP_ERROR(socket, mh) << "No user control message long as " | ||
| if (mh.message_length < 2 || mh.message_length > 32) { |
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LGTM |
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the sibling control-message handlers (OnSetChunkSize, OnAck, OnWindowAckSize, OnSetPeerBandwidth) all validate message_length before touching the body, but OnUserControlMessage only caps the upper bound at 32. reading the code, a user control message with length 0 or 1 reads the 2-byte event type past the end of the stack buffer, and message_length - 2 underflows (uint32_t) to roughly 4G for the event_data StringPiece. require at least 2 bytes up front like the siblings do.