Merge branch 'sctp-handle-wrapped-and-duplicate-reconf-responses'

Jun Yang says:

====================
sctp: handle wrapped and duplicate RECONF responses

Fix response sequence zero lookup first, then make RECONF response
handling idempotent with an outstanding-request bitmask.
====================

Link: https://patch.msgid.link/20260824081832.98717-1-juny24602@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

2 files changed, 33 insertions, 15 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index cccc662561aa..b21f23b736fd 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -2057,7 +2057,7 @@ struct sctp_association {
 	     force_delay:1;
 
 	__u8 strreset_enable;
-	__u8 strreset_outstanding; /* request param count on the fly */
+	__u8 strreset_outstanding; /* request param bitmask on the fly */
 
 	__u32 strreset_outseq; /* Update after receiving response */
 	__u32 strreset_inseq; /* Update after receiving request */
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 2012f61e250e..e4354d58f20b 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -22,6 +22,15 @@
 #include <net/sctp/sm.h>
 #include <net/sctp/stream_sched.h>
 
+#define SCTP_STRRESET_MASK(type) \
+	BIT(ntohs(type) - ntohs(SCTP_PARAM_RESET_OUT_REQUEST))
+#define SCTP_STRRESET_TEST(asoc, type) \
+	((asoc)->strreset_outstanding & SCTP_STRRESET_MASK(type))
+#define SCTP_STRRESET_SET(asoc, type) \
+	((asoc)->strreset_outstanding |= SCTP_STRRESET_MASK(type))
+#define SCTP_STRRESET_CLEAR(asoc, type) \
+	((asoc)->strreset_outstanding &= ~SCTP_STRRESET_MASK(type))
+
 static void sctp_stream_shrink_out(struct sctp_stream *stream, __u16 outcnt)
 {
 	struct sctp_association *asoc;
@@ -372,7 +381,10 @@ int sctp_send_reset_streams(struct sctp_association *asoc,
 		goto out;
 	}
 
-	asoc->strreset_outstanding = out + in;
+	if (out)
+		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_OUT_REQUEST);
+	if (in)
+		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_IN_REQUEST);
 
 out:
 	return retval;
@@ -417,7 +429,7 @@ int sctp_send_reset_assoc(struct sctp_association *asoc)
 		return retval;
 	}
 
-	asoc->strreset_outstanding = 1;
+	SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_TSN_REQUEST);
 
 	return 0;
 }
@@ -474,7 +486,10 @@ int sctp_send_add_streams(struct sctp_association *asoc,
 		goto out;
 	}
 
-	asoc->strreset_outstanding = !!out + !!in;
+	if (out)
+		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_OUT_STREAMS);
+	if (in)
+		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS);
 
 out:
 	return retval;
@@ -482,7 +497,7 @@ out:
 
 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
 			struct sctp_association *asoc, __be32 resp_seq,
-			__be16 type)
+			__be16 type, bool match_seq)
 {
 	struct sctp_chunk *chunk = asoc->strreset_chunk;
 	struct sctp_reconf_chunk *hdr;
@@ -499,7 +514,7 @@ static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
 		 */
 		struct sctp_strreset_tsnreq *req = param.v;
 
-		if ((!resp_seq || req->request_seq == resp_seq) &&
+		if ((!match_seq || req->request_seq == resp_seq) &&
 		    (!type || type == req->param_hdr.type))
 			return param.v;
 	}
@@ -564,13 +579,14 @@ struct sctp_chunk *sctp_process_strreset_outreq(
 	if (asoc->strreset_chunk) {
 		if (!sctp_chunk_lookup_strreset_param(
 				asoc, outreq->response_seq,
-				SCTP_PARAM_RESET_IN_REQUEST)) {
+				SCTP_PARAM_RESET_IN_REQUEST, true) ||
+		    !SCTP_STRRESET_TEST(asoc, SCTP_PARAM_RESET_IN_REQUEST)) {
 			/* same process with outstanding isn't 0 */
 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
 			goto out;
 		}
 
-		asoc->strreset_outstanding--;
+		SCTP_STRRESET_CLEAR(asoc, SCTP_PARAM_RESET_IN_REQUEST);
 		asoc->strreset_outseq++;
 
 		if (!asoc->strreset_outstanding) {
@@ -669,7 +685,7 @@ struct sctp_chunk *sctp_process_strreset_inreq(
 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
 
 	asoc->strreset_chunk = chunk;
-	asoc->strreset_outstanding = 1;
+	SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_OUT_REQUEST);
 	sctp_chunk_hold(asoc->strreset_chunk);
 
 	result = SCTP_STRRESET_PERFORMED;
@@ -816,13 +832,14 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 
 	if (asoc->strreset_chunk) {
 		if (!sctp_chunk_lookup_strreset_param(
-			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
+			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS, false) ||
+		    !SCTP_STRRESET_TEST(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
 			/* same process with outstanding isn't 0 */
 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
 			goto out;
 		}
 
-		asoc->strreset_outstanding--;
+		SCTP_STRRESET_CLEAR(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS);
 		asoc->strreset_outseq++;
 
 		if (!asoc->strreset_outstanding) {
@@ -899,7 +916,7 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
 		goto out;
 
 	asoc->strreset_chunk = chunk;
-	asoc->strreset_outstanding = 1;
+	SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_OUT_STREAMS);
 	sctp_chunk_hold(asoc->strreset_chunk);
 
 	stream->outcnt = outcnt;
@@ -927,8 +944,9 @@ struct sctp_chunk *sctp_process_strreset_resp(
 	struct sctp_paramhdr *req;
 	__u32 result;
 
-	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
-	if (!req)
+	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0,
+					       true);
+	if (!req || !SCTP_STRRESET_TEST(asoc, req->type))
 		return NULL;
 
 	result = ntohl(resp->result);
@@ -1078,7 +1096,7 @@ struct sctp_chunk *sctp_process_strreset_resp(
 			nums, 0, GFP_ATOMIC);
 	}
 
-	asoc->strreset_outstanding--;
+	SCTP_STRRESET_CLEAR(asoc, req->type);
 	asoc->strreset_outseq++;
 
 	/* remove everything for this reconf request */