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authorRémi Denis-Courmont <remi.denis-courmont@nokia.com>2009-09-23 03:17:10 +0000
committerDavid S. Miller <davem@davemloft.net>2009-09-24 15:38:54 -0700
commit582b0b611345fc8d9ab8a0605d2f14c468902719 (patch)
tree3e051d3777171b7f708f5fd89c910d7a62eedfad /net/phonet
parentef87979c273a2348430648ad1d5c2a5e5df50b6e (diff)
Phonet: fix race for port number in concurrent bind()
Allocating a port number to a socket and hashing that socket shall be an atomic operation with regards to other port allocation. Otherwise, we could allocate a port that is already being allocated to another socket. Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/phonet')
-rw-r--r--net/phonet/socket.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index 7a4ee397d2f7..07aa9f08d5fb 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -113,6 +113,8 @@ void pn_sock_unhash(struct sock *sk)
}
EXPORT_SYMBOL(pn_sock_unhash);
+static DEFINE_MUTEX(port_mutex);
+
static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
{
struct sock *sk = sock->sk;
@@ -140,9 +142,11 @@ static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
err = -EINVAL; /* attempt to rebind */
goto out;
}
+ WARN_ON(sk_hashed(sk));
+ mutex_lock(&port_mutex);
err = sk->sk_prot->get_port(sk, pn_port(handle));
if (err)
- goto out;
+ goto out_port;
/* get_port() sets the port, bind() sets the address if applicable */
pn->sobject = pn_object(saddr, pn_port(pn->sobject));
@@ -150,6 +154,8 @@ static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
/* Enable RX on the socket */
sk->sk_prot->hash(sk);
+out_port:
+ mutex_unlock(&port_mutex);
out:
release_sock(sk);
return err;
@@ -357,8 +363,6 @@ const struct proto_ops phonet_stream_ops = {
};
EXPORT_SYMBOL(phonet_stream_ops);
-static DEFINE_MUTEX(port_mutex);
-
/* allocate port for a socket */
int pn_sock_get_port(struct sock *sk, unsigned short sport)
{
@@ -370,9 +374,7 @@ int pn_sock_get_port(struct sock *sk, unsigned short sport)
memset(&try_sa, 0, sizeof(struct sockaddr_pn));
try_sa.spn_family = AF_PHONET;
-
- mutex_lock(&port_mutex);
-
+ WARN_ON(!mutex_is_locked(&port_mutex));
if (!sport) {
/* search free port */
int port, pmin, pmax;
@@ -401,8 +403,6 @@ int pn_sock_get_port(struct sock *sk, unsigned short sport)
else
sock_put(tmpsk);
}
- mutex_unlock(&port_mutex);
-
/* the port must be in use already */
return -EADDRINUSE;

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