diff options
Diffstat (limited to 'net/bluetooth/l2cap_sock.c')
-rw-r--r-- | net/bluetooth/l2cap_sock.c | 57 |
1 files changed, 50 insertions, 7 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 8c329c549ea6..13d070e7738d 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -179,9 +179,17 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, struct l2cap_chan *chan = l2cap_pi(sk)->chan; struct sockaddr_l2 la; int len, err = 0; + bool zapped; BT_DBG("sk %p", sk); + lock_sock(sk); + zapped = sock_flag(sk, SOCK_ZAPPED); + release_sock(sk); + + if (zapped) + return -EINVAL; + if (!addr || alen < offsetofend(struct sockaddr, sa_family) || addr->sa_family != AF_BLUETOOTH) return -EINVAL; @@ -1040,7 +1048,7 @@ done: } /* Kill socket (only if zapped and orphan) - * Must be called on unlocked socket. + * Must be called on unlocked socket, with l2cap channel lock. */ static void l2cap_sock_kill(struct sock *sk) { @@ -1191,6 +1199,7 @@ static int l2cap_sock_release(struct socket *sock) { struct sock *sk = sock->sk; int err; + struct l2cap_chan *chan; BT_DBG("sock %p, sk %p", sock, sk); @@ -1200,9 +1209,17 @@ static int l2cap_sock_release(struct socket *sock) bt_sock_unlink(&l2cap_sk_list, sk); err = l2cap_sock_shutdown(sock, 2); + chan = l2cap_pi(sk)->chan; + + l2cap_chan_hold(chan); + l2cap_chan_lock(chan); sock_orphan(sk); l2cap_sock_kill(sk); + + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); + return err; } @@ -1220,12 +1237,15 @@ static void l2cap_sock_cleanup_listen(struct sock *parent) BT_DBG("child chan %p state %s", chan, state_to_string(chan->state)); + l2cap_chan_hold(chan); l2cap_chan_lock(chan); + __clear_chan_timer(chan); l2cap_chan_close(chan, ECONNRESET); - l2cap_chan_unlock(chan); - l2cap_sock_kill(sk); + + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); } } @@ -1309,6 +1329,9 @@ static void l2cap_sock_close_cb(struct l2cap_chan *chan) { struct sock *sk = chan->data; + if (!sk) + return; + l2cap_sock_kill(sk); } @@ -1317,6 +1340,9 @@ static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) struct sock *sk = chan->data; struct sock *parent; + if (!sk) + return; + BT_DBG("chan %p state %s", chan, state_to_string(chan->state)); /* This callback can be called both for server (BT_LISTEN) @@ -1330,8 +1356,6 @@ static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) parent = bt_sk(sk)->parent; - sock_set_flag(sk, SOCK_ZAPPED); - switch (chan->state) { case BT_OPEN: case BT_BOUND: @@ -1358,8 +1382,11 @@ static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err) break; } - release_sock(sk); + + /* Only zap after cleanup to avoid use after free race */ + sock_set_flag(sk, SOCK_ZAPPED); + } static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, @@ -1465,6 +1492,19 @@ static void l2cap_sock_suspend_cb(struct l2cap_chan *chan) sk->sk_state_change(sk); } +static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb) +{ + struct sock *sk = chan->data; + + switch (chan->mode) { + case L2CAP_MODE_ERTM: + case L2CAP_MODE_STREAMING: + return sk_filter(sk, skb); + } + + return 0; +} + static const struct l2cap_ops l2cap_chan_ops = { .name = "L2CAP Socket Interface", .new_connection = l2cap_sock_new_connection_cb, @@ -1479,14 +1519,17 @@ static const struct l2cap_ops l2cap_chan_ops = { .set_shutdown = l2cap_sock_set_shutdown_cb, .get_sndtimeo = l2cap_sock_get_sndtimeo_cb, .alloc_skb = l2cap_sock_alloc_skb_cb, + .filter = l2cap_sock_filter, }; static void l2cap_sock_destruct(struct sock *sk) { BT_DBG("sk %p", sk); - if (l2cap_pi(sk)->chan) + if (l2cap_pi(sk)->chan) { + l2cap_pi(sk)->chan->data = NULL; l2cap_chan_put(l2cap_pi(sk)->chan); + } if (l2cap_pi(sk)->rx_busy_skb) { kfree_skb(l2cap_pi(sk)->rx_busy_skb); |