Merge branch 'sctp-accept-deadlock'

Karl Heiss says:

====================
sctp: Fix SCTP deadlock

These patches fix a deadlock during accept() of an SCTP connection.

The first patch fixes whitespace issues.

The second patch actually fixes the deadlock race.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2015-09-28 21:03:40 -07:00
commit 51359bfc5b

View file

@ -244,12 +244,13 @@ void sctp_generate_t3_rtx_event(unsigned long peer)
int error;
struct sctp_transport *transport = (struct sctp_transport *) peer;
struct sctp_association *asoc = transport->asoc;
struct net *net = sock_net(asoc->base.sk);
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
/* Check whether a task is in the sock. */
bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy\n", __func__);
/* Try again later. */
@ -272,10 +273,10 @@ void sctp_generate_t3_rtx_event(unsigned long peer)
transport, GFP_ATOMIC);
if (error)
asoc->base.sk->sk_err = -error;
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(asoc->base.sk);
bh_unlock_sock(sk);
sctp_transport_put(transport);
}
@ -285,11 +286,12 @@ out_unlock:
static void sctp_generate_timeout_event(struct sctp_association *asoc,
sctp_event_timeout_t timeout_type)
{
struct net *net = sock_net(asoc->base.sk);
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
int error = 0;
bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy: timer %d\n", __func__,
timeout_type);
@ -312,10 +314,10 @@ static void sctp_generate_timeout_event(struct sctp_association *asoc,
(void *)timeout_type, GFP_ATOMIC);
if (error)
asoc->base.sk->sk_err = -error;
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(asoc->base.sk);
bh_unlock_sock(sk);
sctp_association_put(asoc);
}
@ -365,10 +367,11 @@ void sctp_generate_heartbeat_event(unsigned long data)
int error = 0;
struct sctp_transport *transport = (struct sctp_transport *) data;
struct sctp_association *asoc = transport->asoc;
struct net *net = sock_net(asoc->base.sk);
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy\n", __func__);
/* Try again later. */
@ -388,11 +391,11 @@ void sctp_generate_heartbeat_event(unsigned long data)
asoc->state, asoc->ep, asoc,
transport, GFP_ATOMIC);
if (error)
asoc->base.sk->sk_err = -error;
if (error)
sk->sk_err = -error;
out_unlock:
bh_unlock_sock(asoc->base.sk);
bh_unlock_sock(sk);
sctp_transport_put(transport);
}
@ -403,10 +406,11 @@ void sctp_generate_proto_unreach_event(unsigned long data)
{
struct sctp_transport *transport = (struct sctp_transport *) data;
struct sctp_association *asoc = transport->asoc;
struct net *net = sock_net(asoc->base.sk);
struct sock *sk = asoc->base.sk;
struct net *net = sock_net(sk);
bh_lock_sock(asoc->base.sk);
if (sock_owned_by_user(asoc->base.sk)) {
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
pr_debug("%s: sock is busy\n", __func__);
/* Try again later. */
@ -427,7 +431,7 @@ void sctp_generate_proto_unreach_event(unsigned long data)
asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
out_unlock:
bh_unlock_sock(asoc->base.sk);
bh_unlock_sock(sk);
sctp_association_put(asoc);
}