Bluetooth: invert locking order in connect path
This move some checking code that was in l2cap_sock_connect() to
l2cap_chan_connect(). Thus we can invert the lock calls, i.e., call
lock_sock() before hci_dev_lock() to avoid a deadlock scenario.
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index f791374..c0d168a 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -806,7 +806,8 @@
struct l2cap_chan *l2cap_chan_create(struct sock *sk);
void l2cap_chan_close(struct l2cap_chan *chan, int reason);
void l2cap_chan_destroy(struct l2cap_chan *chan);
-int l2cap_chan_connect(struct l2cap_chan *chan);
+inline int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
+ bdaddr_t *dst);
int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
u32 priority);
void l2cap_chan_busy(struct l2cap_chan *chan, int busy);
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index a78cdf7..d616519 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1144,11 +1144,10 @@
return c1;
}
-int l2cap_chan_connect(struct l2cap_chan *chan)
+inline int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *dst)
{
struct sock *sk = chan->sk;
bdaddr_t *src = &bt_sk(sk)->src;
- bdaddr_t *dst = &bt_sk(sk)->dst;
struct l2cap_conn *conn;
struct hci_conn *hcon;
struct hci_dev *hdev;
@@ -1164,6 +1163,61 @@
hci_dev_lock(hdev);
+ lock_sock(sk);
+
+ /* PSM must be odd and lsb of upper byte must be 0 */
+ if ((__le16_to_cpu(psm) & 0x0101) != 0x0001 && !cid &&
+ chan->chan_type != L2CAP_CHAN_RAW) {
+ err = -EINVAL;
+ goto done;
+ }
+
+ if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !(psm || cid)) {
+ err = -EINVAL;
+ goto done;
+ }
+
+ switch (chan->mode) {
+ case L2CAP_MODE_BASIC:
+ break;
+ case L2CAP_MODE_ERTM:
+ case L2CAP_MODE_STREAMING:
+ if (!disable_ertm)
+ break;
+ /* fall through */
+ default:
+ err = -ENOTSUPP;
+ goto done;
+ }
+
+ switch (sk->sk_state) {
+ case BT_CONNECT:
+ case BT_CONNECT2:
+ case BT_CONFIG:
+ /* Already connecting */
+ err = 0;
+ goto done;
+
+ case BT_CONNECTED:
+ /* Already connected */
+ err = -EISCONN;
+ goto done;
+
+ case BT_OPEN:
+ case BT_BOUND:
+ /* Can connect */
+ break;
+
+ default:
+ err = -EBADFD;
+ goto done;
+ }
+
+ /* Set destination address and psm */
+ bacpy(&bt_sk(sk)->dst, src);
+ chan->psm = psm;
+ chan->dcid = cid;
+
auth_type = l2cap_get_auth_type(chan);
if (chan->dcid == L2CAP_CID_LE_DATA)
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index fbdc8b3..6c7d432 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -121,70 +121,15 @@
if (la.l2_cid && la.l2_psm)
return -EINVAL;
- lock_sock(sk);
-
- if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED
- && !(la.l2_psm || la.l2_cid)) {
- err = -EINVAL;
- goto done;
- }
-
- switch (chan->mode) {
- case L2CAP_MODE_BASIC:
- break;
- case L2CAP_MODE_ERTM:
- case L2CAP_MODE_STREAMING:
- if (!disable_ertm)
- break;
- /* fall through */
- default:
- err = -ENOTSUPP;
- goto done;
- }
-
- switch (sk->sk_state) {
- case BT_CONNECT:
- case BT_CONNECT2:
- case BT_CONFIG:
- /* Already connecting */
- goto wait;
-
- case BT_CONNECTED:
- /* Already connected */
- err = -EISCONN;
- goto done;
-
- case BT_OPEN:
- case BT_BOUND:
- /* Can connect */
- break;
-
- default:
- err = -EBADFD;
- goto done;
- }
-
- /* PSM must be odd and lsb of upper byte must be 0 */
- if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001 && !la.l2_cid &&
- chan->chan_type != L2CAP_CHAN_RAW) {
- err = -EINVAL;
- goto done;
- }
-
- /* Set destination address and psm */
- bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr);
- chan->psm = la.l2_psm;
- chan->dcid = la.l2_cid;
-
- err = l2cap_chan_connect(chan);
+ err = l2cap_chan_connect(chan, la.l2_psm, la.l2_cid, &la.l2_bdaddr);
if (err)
goto done;
-wait:
err = bt_sock_wait_state(sk, BT_CONNECTED,
sock_sndtimeo(sk, flags & O_NONBLOCK));
done:
- release_sock(sk);
+ if (sock_owned_by_user(sk))
+ release_sock(sk);
return err;
}