Commit dadb50cc authored Aug 22, 2009 by Wei Yongjun Committed by Vlad Yasevich Sep 04, 2009

sctp: fix check the chunk length of received HEARTBEAT-ACK chunk



The receiver of the HEARTBEAT should respond with a HEARTBEAT ACK
that contains the Heartbeat Information field copied from the
received HEARTBEAT chunk. So the received HEARTBEAT-ACK chunk
must have a length of:
  sizeof(sctp_chunkhdr_t) + sizeof(sctp_sender_hb_info_t)

A badly formatted HB-ACK chunk, it is possible that we may access
invalid memory.  We should really make sure that the chunk format
is what we expect, before attempting to touch the data.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

parent a2f36eec

net/sctp/sm_statefuns.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1115,7 +1115,8 @@ sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
		return sctp_sf_pdiscard(ep, asoc, type, arg, commands);

		/* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
		if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
		if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
		sizeof(sctp_sender_hb_info_t)))
		return sctp_sf_violation_chunklen(ep, asoc, type, arg,
		commands);