From: Dean Jenkins Date: Tue, 23 Jun 2015 16:59:32 +0000 (+0100) Subject: Bluetooth: L2CAP ERTM shutdown protect sk and chan X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2baea85dec1aebe0b100d4836dee8bcf29a51e94;p=linux-beck.git Bluetooth: L2CAP ERTM shutdown protect sk and chan During execution of l2cap_sock_shutdown() which might sleep, the sk and chan structures can be in an unlocked condition which potentially allows the structures to be freed by other running threads. Therefore, there is a possibility of a malfunction or memory reuse after being freed. Keep the sk and chan structures alive during the execution of l2cap_sock_shutdown() by using their respective hold and put functions. This allows the structures to be freeable at the end of l2cap_sock_shutdown(). Signed-off-by: Kautuk Consul Signed-off-by: Dean Jenkins Signed-off-by: Marcel Holtmann --- diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 244287706f91..3794c2386c21 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1098,7 +1098,12 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) if (!sk) return 0; + /* prevent sk structure from being freed whilst unlocked */ + sock_hold(sk); + chan = l2cap_pi(sk)->chan; + /* prevent chan structure from being freed whilst unlocked */ + l2cap_chan_hold(chan); conn = chan->conn; BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); @@ -1134,6 +1139,9 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) if (conn) mutex_unlock(&conn->chan_lock); + l2cap_chan_put(chan); + sock_put(sk); + return err; }