[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>

8 files changed, 38 insertions, 14 deletions

diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index a91fee4f2705..67df99e2e5c8 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;
 
+        write_lock(&bt_proto_lock);
+
         if (bt_proto[proto])
-                return -EEXIST;
+                err = -EEXIST;
+        else
+                bt_proto[proto] = ops;
 
-        bt_proto[proto] = ops;
-        return 0;
+        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;
 
+        write_lock(&bt_proto_lock);
+
         if (!bt_proto[proto])
-                return -ENOENT;
+                err = -ENOENT;
+        else
+                bt_proto[proto] = NULL;
 
-        bt_proto[proto] = NULL;
-        return 0;
+        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 @@ static int bt_sock_create(struct socket *sock, int proto)
                 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; 
 }
 
diff --git a/net/bluetooth/bnep/sock.c b/net/bluetooth/bnep/sock.c
index 5d9d6f14b310..5563db1bf526 100644
--- a/net/bluetooth/bnep/sock.c
+++ b/net/bluetooth/bnep/sock.c
@@ -214,7 +214,7 @@ static int bnep_sock_create(struct socket *sock, int protocol)
         if (sock->type != SOCK_RAW)
                 return -ESOCKTNOSUPPORT;
 
-        sk = sk_alloc(PF_BLUETOOTH, GFP_KERNEL, &bnep_proto, 1);
+        sk = sk_alloc(PF_BLUETOOTH, GFP_ATOMIC, &bnep_proto, 1);
         if (!sk)
                 return -ENOMEM;
 
diff --git a/net/bluetooth/cmtp/sock.c b/net/bluetooth/cmtp/sock.c
index 0547edd57734..53295d33dc5c 100644
--- a/net/bluetooth/cmtp/sock.c
+++ b/net/bluetooth/cmtp/sock.c
@@ -205,7 +205,7 @@ static int cmtp_sock_create(struct socket *sock, int protocol)
         if (sock->type != SOCK_RAW)
                 return -ESOCKTNOSUPPORT;
 
-        sk = sk_alloc(PF_BLUETOOTH, GFP_KERNEL, &cmtp_proto, 1);
+        sk = sk_alloc(PF_BLUETOOTH, GFP_ATOMIC, &cmtp_proto, 1);
         if (!sk)
                 return -ENOMEM;
 
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 1a35d343e08a..f26a9eb49945 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -618,7 +618,7 @@ static int hci_sock_create(struct socket *sock, int protocol)
 
         sock->ops = &hci_sock_ops;
 
-        sk = sk_alloc(PF_BLUETOOTH, GFP_KERNEL, &hci_sk_proto, 1);
+        sk = sk_alloc(PF_BLUETOOTH, GFP_ATOMIC, &hci_sk_proto, 1);
         if (!sk)
                 return -ENOMEM;
 
diff --git a/net/bluetooth/hidp/sock.c b/net/bluetooth/hidp/sock.c
index 6242446aa270..407fba43c1b9 100644
--- a/net/bluetooth/hidp/sock.c
+++ b/net/bluetooth/hidp/sock.c
@@ -256,7 +256,7 @@ static int hidp_sock_create(struct socket *sock, int protocol)
         if (sock->type != SOCK_RAW)
                 return -ESOCKTNOSUPPORT;
 
-        sk = sk_alloc(PF_BLUETOOTH, GFP_KERNEL, &hidp_proto, 1);
+        sk = sk_alloc(PF_BLUETOOTH, GFP_ATOMIC, &hidp_proto, 1);
         if (!sk)
                 return -ENOMEM;
 
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 66fc621a077c..2b3dcb8f90fa 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -559,7 +559,7 @@ static int l2cap_sock_create(struct socket *sock, int protocol)
 
         sock->ops = &l2cap_sock_ops;
 
-        sk = l2cap_sock_alloc(sock, protocol, GFP_KERNEL);
+        sk = l2cap_sock_alloc(sock, protocol, GFP_ATOMIC);
         if (!sk)
                 return -ENOMEM;
 
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 530cc41f3a22..544d65b7baa7 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -336,7 +336,8 @@ static int rfcomm_sock_create(struct socket *sock, int protocol)
 
         sock->ops = &rfcomm_sock_ops;
 
-        if (!(sk = rfcomm_sock_alloc(sock, protocol, GFP_KERNEL)))
+        sk = rfcomm_sock_alloc(sock, protocol, GFP_ATOMIC);
+        if (!sk)
                 return -ENOMEM;
 
         rfcomm_sock_init(sk, NULL);
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 14b0f6930637..5d13d4f31753 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -452,7 +452,8 @@ static int sco_sock_create(struct socket *sock, int protocol)
 
         sock->ops = &sco_sock_ops;
 
-        if (!(sk = sco_sock_alloc(sock, protocol, GFP_KERNEL)))
+        sk = sco_sock_alloc(sock, protocol, GFP_ATOMIC);
+        if (!sk)
                 return -ENOMEM;
 
         sco_sock_init(sk, NULL);