From 0a2fbac197441ebeafbbef09d4bbc0b5e73716d7 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Tue, 25 Jun 2013 18:17:29 +0200 Subject: net: sctp: decouple cleaning some socket data from endpoint Rather instead of having the endpoint clean the garbage from the socket, use a sk_destruct handler sctp_destruct_sock(), that does the job for that when there are no more references on the socket. At least do this for our crypto transform through crypto_free_hash() that is allocated when in listening state. Also, perform sctp_put_port() only when sk is valid. At a later point in time we can still determine if there's an option of placing this into sk_prot->unhash() or sctp_endpoint_free() without any races. For now, leave it in sctp_endpoint_destroy() though. Signed-off-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/endpointola.c | 19 ++++++++++--------- net/sctp/socket.c | 16 +++++++++++++++- 2 files changed, 25 insertions(+), 10 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c index a8b26741c0af..b26999d508ba 100644 --- a/net/sctp/endpointola.c +++ b/net/sctp/endpointola.c @@ -247,10 +247,9 @@ void sctp_endpoint_free(struct sctp_endpoint *ep) /* Final destructor for endpoint. */ static void sctp_endpoint_destroy(struct sctp_endpoint *ep) { - SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); + struct sock *sk; - /* Free up the HMAC transform. */ - crypto_free_hash(sctp_sk(ep->base.sk)->hmac); + SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); /* Free the digest buffer */ kfree(ep->digest); @@ -271,13 +270,15 @@ static void sctp_endpoint_destroy(struct sctp_endpoint *ep) memset(ep->secret_key, 0, sizeof(ep->secret_key)); - /* Remove and free the port */ - if (sctp_sk(ep->base.sk)->bind_hash) - sctp_put_port(ep->base.sk); - /* Give up our hold on the sock. */ - if (ep->base.sk) - sock_put(ep->base.sk); + sk = ep->base.sk; + if (sk != NULL) { + /* Remove and free the port */ + if (sctp_sk(sk)->bind_hash) + sctp_put_port(sk); + + sock_put(sk); + } kfree(ep); SCTP_DBG_OBJCNT_DEC(ep); diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 4c47e5578d71..ba9359c20c8a 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -93,6 +93,7 @@ static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p); static int sctp_wait_for_connect(struct sctp_association *, long *timeo_p); static int sctp_wait_for_accept(struct sock *sk, long timeo); static void sctp_wait_for_close(struct sock *sk, long timeo); +static void sctp_destruct_sock(struct sock *sk); static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt, union sctp_addr *addr, int len); static int sctp_bindx_add(struct sock *, struct sockaddr *, int); @@ -3966,6 +3967,8 @@ static int sctp_init_sock(struct sock *sk) sp->hmac = NULL; + sk->sk_destruct = sctp_destruct_sock; + SCTP_DBG_OBJCNT_INC(sock); local_bh_disable(); @@ -4008,6 +4011,17 @@ static void sctp_destroy_sock(struct sock *sk) local_bh_enable(); } +/* Triggered when there are no references on the socket anymore */ +static void sctp_destruct_sock(struct sock *sk) +{ + struct sctp_sock *sp = sctp_sk(sk); + + /* Free up the HMAC transform. */ + crypto_free_hash(sp->hmac); + + inet_sock_destruct(sk); +} + /* API 4.1.7 shutdown() - TCP Style Syntax * int shutdown(int socket, int how); * @@ -6848,7 +6862,7 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk, newsk->sk_reuse = sk->sk_reuse; newsk->sk_shutdown = sk->sk_shutdown; - newsk->sk_destruct = inet_sock_destruct; + newsk->sk_destruct = sctp_destruct_sock; newsk->sk_family = sk->sk_family; newsk->sk_protocol = IPPROTO_SCTP; newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv; -- cgit v1.2.3