Subject: [PATCH 12/24] net: sctp: Fix negotiation of the number of data streams.

From: David Laight <[email-masked]>
Date: Wed, 19 Aug 2020 14:40:52 +0000

[ Upstream commit ab921f3cdbec01c68705a7ade8bec628d541fc2b ]

The number of output and input streams was never being reduced, eg when
processing received INIT or INIT_ACK chunks.
The effect is that DATA chunks can be sent with invalid stream ids
and then discarded by the remote system.

Fixes: 2075e50caf5ea ("sctp: convert to genradix")
Signed-off-by: David Laight <[email-masked]>
Acked-by: Marcelo Ricardo Leitner <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/sctp/stream.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index bda2536dd740..6dc95dcc0ff4 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -88,12 +88,13 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
 	int ret;
 
 	if (outcnt <= stream->outcnt)
-		return 0;
+		goto out;
 
 	ret = genradix_prealloc(&stream->out, outcnt, gfp);
 	if (ret)
 		return ret;
 
+out:
 	stream->outcnt = outcnt;
 	return 0;
 }
@@ -104,12 +105,13 @@ static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
 	int ret;
 
 	if (incnt <= stream->incnt)
-		return 0;
+		goto out;
 
 	ret = genradix_prealloc(&stream->in, incnt, gfp);
 	if (ret)
 		return ret;
 
+out:
 	stream->incnt = incnt;
 	return 0;
 }
-- 
2.26.2