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Commit 2342b8d9 authored by Xin Long's avatar Xin Long Committed by David S. Miller
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sctp: make sure stream nums can match optlen in sctp_setsockopt_reset_streams 



Now in sctp_setsockopt_reset_streams, it only does the check
optlen < sizeof(*params) for optlen. But it's not enough, as
params->srs_number_streams should also match optlen.

If the streams in params->srs_stream_list are less than stream
nums in params->srs_number_streams, later when dereferencing
the stream list, it could cause a slab-out-of-bounds crash, as
reported by syzbot.

This patch is to fix it by also checking the stream numbers in
sctp_setsockopt_reset_streams to make sure at least it's not
greater than the streams in the list.

Fixes: 7f9d68ac ("sctp: implement sender-side procedures for SSN Reset Request Parameter")
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Acked-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8f659a03

net/sctp/socket.c

+5 −1
Original line number Diff line number Diff line
@@ -3891,13 +3891,17 @@ static int sctp_setsockopt_reset_streams(struct sock *sk, 
	struct sctp_association *asoc;

	int retval = -EINVAL;



	if (optlen < sizeof(struct sctp_reset_streams))

	if (optlen < sizeof(*params))

		return -EINVAL;



	params = memdup_user(optval, optlen);

	if (IS_ERR(params))

		return PTR_ERR(params);



	if (params->srs_number_streams * sizeof(__u16) >

	    optlen - sizeof(*params))

		goto out;



	asoc = sctp_id2assoc(sk, params->srs_assoc_id);

	if (!asoc)

		goto out;