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Commit 3a9ca1e2 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'sctp-dup-stream-reconf-events' 



Xin Long says:

====================
sctp: add proper process for duplicated stream reconf requests

Now sctp stream reconf will process a request again even if it's seqno
is less than asoc->strreset_inseq. It may cause a replay attack.

This patchset is to avoid it by add proper process for all duplicated
stream reconf requests.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents b89f04c6 6c801387

include/net/sctp/structs.h

+1 −0
Original line number Diff line number Diff line
@@ -1889,6 +1889,7 @@ struct sctp_association { 


	__u32 strreset_outseq; /* Update after receiving response */

	__u32 strreset_inseq; /* Update after receiving request */

	__u32 strreset_result[2]; /* save the results of last 2 responses */



	struct sctp_chunk *strreset_chunk; /* save request chunk */

net/sctp/stream.c

+73 −23
Original line number Diff line number Diff line
@@ -344,6 +344,13 @@ static sctp_paramhdr_t *sctp_chunk_lookup_strreset_param( 
	return NULL;

}



static void sctp_update_strreset_result(struct sctp_association *asoc,

					__u32 result)

{

	asoc->strreset_result[1] = asoc->strreset_result[0];

	asoc->strreset_result[0] = result;

}



struct sctp_chunk *sctp_process_strreset_outreq(

				struct sctp_association *asoc,

				union sctp_params param,
@@ -360,15 +367,19 @@ struct sctp_chunk *sctp_process_strreset_outreq( 
	if (ntohl(outreq->send_reset_at_tsn) >

	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {

		result = SCTP_STRRESET_IN_PROGRESS;

		goto out;

		goto err;

	}



	if (request_seq > asoc->strreset_inseq) {

	if (TSN_lt(asoc->strreset_inseq, request_seq) ||

	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {

		result = SCTP_STRRESET_ERR_BAD_SEQNO;

		goto out;

	} else if (request_seq == asoc->strreset_inseq) {

		asoc->strreset_inseq++;

		goto err;

	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {

		i = asoc->strreset_inseq - request_seq - 1;

		result = asoc->strreset_result[i];

		goto err;

	}

	asoc->strreset_inseq++;



	/* Check strreset_enable after inseq inc, as sender cannot tell

	 * the peer doesn't enable strreset after receiving response with
@@ -427,6 +438,8 @@ struct sctp_chunk *sctp_process_strreset_outreq( 
		GFP_ATOMIC);



out:

	sctp_update_strreset_result(asoc, result);

err:

	return sctp_make_strreset_resp(asoc, result, request_seq);

}
@@ -443,12 +456,18 @@ struct sctp_chunk *sctp_process_strreset_inreq( 
	__u32 request_seq;



	request_seq = ntohl(inreq->request_seq);

	if (request_seq > asoc->strreset_inseq) {

	if (TSN_lt(asoc->strreset_inseq, request_seq) ||

	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {

		result = SCTP_STRRESET_ERR_BAD_SEQNO;

		goto out;

	} else if (request_seq == asoc->strreset_inseq) {

		asoc->strreset_inseq++;

		goto err;

	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {

		i = asoc->strreset_inseq - request_seq - 1;

		result = asoc->strreset_result[i];

		if (result == SCTP_STRRESET_PERFORMED)

			return NULL;

		goto err;

	}

	asoc->strreset_inseq++;



	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))

		goto out;
@@ -483,10 +502,14 @@ struct sctp_chunk *sctp_process_strreset_inreq( 
	asoc->strreset_outstanding = 1;

	sctp_chunk_hold(asoc->strreset_chunk);



	result = SCTP_STRRESET_PERFORMED;



	*evp = sctp_ulpevent_make_stream_reset_event(asoc,

		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);



out:

	sctp_update_strreset_result(asoc, result);

err:

	if (!chunk)

		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
@@ -506,12 +529,21 @@ struct sctp_chunk *sctp_process_strreset_tsnreq( 
	__u16 i;



	request_seq = ntohl(tsnreq->request_seq);

	if (request_seq > asoc->strreset_inseq) {

	if (TSN_lt(asoc->strreset_inseq, request_seq) ||

	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {

		result = SCTP_STRRESET_ERR_BAD_SEQNO;

		goto out;

	} else if (request_seq == asoc->strreset_inseq) {

		asoc->strreset_inseq++;

		goto err;

	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {

		i = asoc->strreset_inseq - request_seq - 1;

		result = asoc->strreset_result[i];

		if (result == SCTP_STRRESET_PERFORMED) {

			next_tsn = asoc->next_tsn;

			init_tsn =

				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;

		}

		goto err;

	}

	asoc->strreset_inseq++;



	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))

		goto out;
@@ -568,6 +600,8 @@ struct sctp_chunk *sctp_process_strreset_tsnreq( 
						    next_tsn, GFP_ATOMIC);



out:

	sctp_update_strreset_result(asoc, result);

err:

	return sctp_make_strreset_tsnresp(asoc, result, request_seq,

					  next_tsn, init_tsn);

}
@@ -582,15 +616,19 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out( 
	__u32 result = SCTP_STRRESET_DENIED;

	struct sctp_stream_in *streamin;

	__u32 request_seq, incnt;

	__u16 in;

	__u16 in, i;



	request_seq = ntohl(addstrm->request_seq);

	if (request_seq > asoc->strreset_inseq) {

	if (TSN_lt(asoc->strreset_inseq, request_seq) ||

	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {

		result = SCTP_STRRESET_ERR_BAD_SEQNO;

		goto out;

	} else if (request_seq == asoc->strreset_inseq) {

		asoc->strreset_inseq++;

		goto err;

	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {

		i = asoc->strreset_inseq - request_seq - 1;

		result = asoc->strreset_result[i];

		goto err;

	}

	asoc->strreset_inseq++;



	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))

		goto out;
@@ -638,6 +676,8 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out( 
		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);



out:

	sctp_update_strreset_result(asoc, result);

err:

	return sctp_make_strreset_resp(asoc, result, request_seq);

}
@@ -652,15 +692,21 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in( 
	struct sctp_stream_out *streamout;

	struct sctp_chunk *chunk = NULL;

	__u32 request_seq, outcnt;

	__u16 out;

	__u16 out, i;



	request_seq = ntohl(addstrm->request_seq);

	if (request_seq > asoc->strreset_inseq) {

	if (TSN_lt(asoc->strreset_inseq, request_seq) ||

	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {

		result = SCTP_STRRESET_ERR_BAD_SEQNO;

		goto out;

	} else if (request_seq == asoc->strreset_inseq) {

		asoc->strreset_inseq++;

		goto err;

	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {

		i = asoc->strreset_inseq - request_seq - 1;

		result = asoc->strreset_result[i];

		if (result == SCTP_STRRESET_PERFORMED)

			return NULL;

		goto err;

	}

	asoc->strreset_inseq++;



	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))

		goto out;
@@ -693,10 +739,14 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in( 


	stream->outcnt = outcnt;



	result = SCTP_STRRESET_PERFORMED;



	*evp = sctp_ulpevent_make_stream_change_event(asoc,

		0, 0, ntohs(addstrm->number_of_streams), GFP_ATOMIC);



out:

	sctp_update_strreset_result(asoc, result);

err:

	if (!chunk)

		chunk = sctp_make_strreset_resp(asoc, result, request_seq);