[Bluetooth] Add locking for bt_proto array manipulation
The bt_proto array needs to be protected by some kind of locking to
prevent a race condition between bt_sock_create and bt_sock_register.
And in addition all calls to sk_alloc need to be made GFP_ATOMIC now.
Signed-off-by: Masatake YAMATO <jet@gyve.org>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index a91fee4..67df99e 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -53,36 +53,51 @@
/* Bluetooth sockets */
#define BT_MAX_PROTO 8
static struct net_proto_family *bt_proto[BT_MAX_PROTO];
+static DEFINE_RWLOCK(bt_proto_lock);
int bt_sock_register(int proto, struct net_proto_family *ops)
{
+ int err = 0;
+
if (proto < 0 || proto >= BT_MAX_PROTO)
return -EINVAL;
- if (bt_proto[proto])
- return -EEXIST;
+ write_lock(&bt_proto_lock);
- bt_proto[proto] = ops;
- return 0;
+ if (bt_proto[proto])
+ err = -EEXIST;
+ else
+ bt_proto[proto] = ops;
+
+ write_unlock(&bt_proto_lock);
+
+ return err;
}
EXPORT_SYMBOL(bt_sock_register);
int bt_sock_unregister(int proto)
{
+ int err = 0;
+
if (proto < 0 || proto >= BT_MAX_PROTO)
return -EINVAL;
- if (!bt_proto[proto])
- return -ENOENT;
+ write_lock(&bt_proto_lock);
- bt_proto[proto] = NULL;
- return 0;
+ if (!bt_proto[proto])
+ err = -ENOENT;
+ else
+ bt_proto[proto] = NULL;
+
+ write_unlock(&bt_proto_lock);
+
+ return err;
}
EXPORT_SYMBOL(bt_sock_unregister);
static int bt_sock_create(struct socket *sock, int proto)
{
- int err = 0;
+ int err;
if (proto < 0 || proto >= BT_MAX_PROTO)
return -EINVAL;
@@ -92,11 +107,18 @@
request_module("bt-proto-%d", proto);
}
#endif
+
err = -EPROTONOSUPPORT;
+
+ read_lock(&bt_proto_lock);
+
if (bt_proto[proto] && try_module_get(bt_proto[proto]->owner)) {
err = bt_proto[proto]->create(sock, proto);
module_put(bt_proto[proto]->owner);
}
+
+ read_unlock(&bt_proto_lock);
+
return err;
}