From bec9640bb0d451813b1bb1f2cc13a5bfb17c3e48 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Thu, 30 Jul 2009 18:08:28 -0400 Subject: [PATCH] sctp: Disallow new connection on a closing socket If a socket has a lot of association that are in the process of of being closed/aborted, it is possible for a remote to establish new associations during the time period that the old ones are shutting down. If this was a result of a close() call, there will be no socket and will cause a memory leak. We'll prevent this by setting the socket state to CLOSING and disallow new associations when in this state. Signed-off-by: Vlad Yasevich --- include/net/sctp/constants.h | 2 +- net/sctp/sm_statefuns.c | 9 +++++++++ net/sctp/socket.c | 1 + 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h index 8bc25f7b04ce..af8c1508109e 100644 --- a/include/net/sctp/constants.h +++ b/include/net/sctp/constants.h @@ -231,7 +231,7 @@ typedef enum { SCTP_SS_LISTENING = TCP_LISTEN, SCTP_SS_ESTABLISHING = TCP_SYN_SENT, SCTP_SS_ESTABLISHED = TCP_ESTABLISHED, - SCTP_SS_DISCONNECTING = TCP_CLOSING, + SCTP_SS_CLOSING = TCP_CLOSING, } sctp_sock_state_t; /* These functions map various type to printable names. */ diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 7288192f7df5..50225dd2e6dc 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -334,6 +334,15 @@ sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep, if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) return sctp_sf_pdiscard(ep, asoc, type, arg, commands); + /* If the INIT is coming toward a closing socket, we'll send back + * and ABORT. Essentially, this catches the race of INIT being + * backloged to the socket at the same time as the user isses close(). + * Since the socket and all its associations are going away, we + * can treat this OOTB + */ + if (sctp_sstate(ep->base.sk, CLOSING)) + return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); + /* Verify the INIT chunk before processing it. */ err_chunk = NULL; if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 971890dbfea0..a7e544e3f28a 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1361,6 +1361,7 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout) sctp_lock_sock(sk); sk->sk_shutdown = SHUTDOWN_MASK; + sk->sk_state = SCTP_SS_CLOSING; ep = sctp_sk(sk)->ep; -- GitLab