Re: [PATCH 3.18 010/145] sctp: avoid BUG_ON on sctp_wait_for_sndbuf

Marcelo Ricardo Leitner
2017-04-17T20:01:02Z

Em 16-04-2017 07:48, Greg Kroah-Hartman escreveu:
> 3.18-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
>
>
> [ Upstream commit 2dcab598484185dea7ec22219c76dcdd59e3cb90 ]

Hi Greg. Are you also including dfcb9f4f99f1 ("sctp: deny peeloff
operation on asocs with threads sleeping on it")
It's a follow-up fix for this one, would be good to have it too.

>
> Alexander Popov reported that an application may trigger a BUG_ON in
> sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is
> waiting on it to queue more data and meanwhile another thread peels off
> the association being used by the first thread.
>
> This patch replaces the BUG_ON call with a proper error handling. It
> will return -EPIPE to the original sendmsg call, similarly to what would
> have been done if the association wasn't found in the first place.
>
> Acked-by: Alexander Popov <alex.popov@linux.com>
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
> Reviewed-by: Xin Long <lucien.xin@gmail.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> net/sctp/socket.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -6962,7 +6962,8 @@ static int sctp_wait_for_sndbuf(struct s
> */
> release_sock(sk);
> current_timeo = schedule_timeout(current_timeo);
> - BUG_ON(sk != asoc->base.sk);
> + if (sk != asoc->base.sk)
> + goto do_error;
> lock_sock(sk);
>
> *timeo_p = current_timeo;
>
>