[PATCH net] sctp: clear the new asoc's stream outcnt in sctp_stream_update

[PATCH net] sctp: clear the new asoc's stream outcnt in sctp_stream_update

[Xin Long]

When processing a duplicate cookie-echo chunk, sctp moves the new
temp asoc's stream out/in into the old asoc, and later frees this
new temp asoc.

But now after this move, the new temp asoc's stream->outcnt is not
cleared while stream->out is set to NULL, which would cause a same
crash as the one fixed in Commit 79d0895140e9 ("sctp: fix error
path in sctp_stream_init") when freeing this asoc later.

This fix is to clear this outcnt in sctp_stream_update.

Fixes: f952be79cebd ("sctp: introduce struct sctp_stream_out_ext")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/stream.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index f799043..f1f1d1b 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -240,6 +240,8 @@ void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
 
 	new->out = NULL;
 	new->in  = NULL;
+	new->outcnt = 0;
+	new->incnt  = 0;
 }
 
 static int sctp_send_reconf(struct sctp_association *asoc,
-- 
2.1.0

Re: [PATCH net] sctp: clear the new asoc's stream outcnt in sctp_stream_update

[Neil Horman]

On Thu, Apr 26, 2018 at 03:21:44PM +0800, Xin Long wrote:
> When processing a duplicate cookie-echo chunk, sctp moves the new
> temp asoc's stream out/in into the old asoc, and later frees this
> new temp asoc.
> 
> But now after this move, the new temp asoc's stream->outcnt is not
> cleared while stream->out is set to NULL, which would cause a same
> crash as the one fixed in Commit 79d0895140e9 ("sctp: fix error
> path in sctp_stream_init") when freeing this asoc later.
> 
> This fix is to clear this outcnt in sctp_stream_update.
> 
> Fixes: f952be79cebd ("sctp: introduce struct sctp_stream_out_ext")
> Reported-by: Jianwen Ji <jiji@redhat.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---
>  net/sctp/stream.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/sctp/stream.c b/net/sctp/stream.c
> index f799043..f1f1d1b 100644
> --- a/net/sctp/stream.c
> +++ b/net/sctp/stream.c
> @@ -240,6 +240,8 @@ void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
>  
>  	new->out = NULL;
>  	new->in  = NULL;
> +	new->outcnt = 0;
> +	new->incnt  = 0;
>  }
>  
>  static int sctp_send_reconf(struct sctp_association *asoc,
> -- 
> 2.1.0
> 
> 
Acked-by: Neil Horman <nhorman@tuxdriver.com>

Re: [PATCH net] sctp: clear the new asoc's stream outcnt in sctp_stream_update

[Marcelo Ricardo Leitner]

On Thu, Apr 26, 2018 at 03:21:44PM +0800, Xin Long wrote:
> When processing a duplicate cookie-echo chunk, sctp moves the new
> temp asoc's stream out/in into the old asoc, and later frees this
> new temp asoc.
>
> But now after this move, the new temp asoc's stream->outcnt is not
> cleared while stream->out is set to NULL, which would cause a same
> crash as the one fixed in Commit 79d0895140e9 ("sctp: fix error
> path in sctp_stream_init") when freeing this asoc later.
>
> This fix is to clear this outcnt in sctp_stream_update.
>
> Fixes: f952be79cebd ("sctp: introduce struct sctp_stream_out_ext")
> Reported-by: Jianwen Ji <jiji@redhat.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

> ---
>  net/sctp/stream.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/sctp/stream.c b/net/sctp/stream.c
> index f799043..f1f1d1b 100644
> --- a/net/sctp/stream.c
> +++ b/net/sctp/stream.c
> @@ -240,6 +240,8 @@ void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
>
>  	new->out = NULL;
>  	new->in  = NULL;
> +	new->outcnt = 0;
> +	new->incnt  = 0;
>  }
>
>  static int sctp_send_reconf(struct sctp_association *asoc,
> --
> 2.1.0
>
> --
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Re: [PATCH net] sctp: clear the new asoc's stream outcnt in sctp_stream_update

[David Miller]

From: Xin Long <lucien.xin@gmail.com>
Date: Thu, 26 Apr 2018 15:21:44 +0800

> When processing a duplicate cookie-echo chunk, sctp moves the new
> temp asoc's stream out/in into the old asoc, and later frees this
> new temp asoc.
> 
> But now after this move, the new temp asoc's stream->outcnt is not
> cleared while stream->out is set to NULL, which would cause a same
> crash as the one fixed in Commit 79d0895140e9 ("sctp: fix error
> path in sctp_stream_init") when freeing this asoc later.
> 
> This fix is to clear this outcnt in sctp_stream_update.
> 
> Fixes: f952be79cebd ("sctp: introduce struct sctp_stream_out_ext")
> Reported-by: Jianwen Ji <jiji@redhat.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied and queued up for -stable.