From: Alexander Ofitserov oficerovas@altlinux.org
From: Pauli Virtanen pav@iki.fi
commit 3dcaa192ac21 ("Bluetooth: SCO: fix sco_conn related locking and validity issues")
Operations that check/update sk_state and access conn should hold lock_sock, otherwise they can race.
The order of taking locks is hci_dev_lock > lock_sock > sco_conn_lock, which is how it is in connect/disconnect_cfm -> sco_conn_del -> sco_chan_del.
Fix locking in sco_connect to take lock_sock around updating sk_state and conn.
sco_conn_del must not occur during sco_connect, as it frees the sco_conn. Hold hdev->lock longer to prevent that.
sco_conn_add shall return sco_conn with valid hcon. Make it so also when reusing an old SCO connection waiting for disconnect timeout (see __sco_sock_close where conn->hcon is set to NULL).
This should not reintroduce the issue fixed in the earlier commit 9a8ec9e8ebb5 ("Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm"), the relevant fix of releasing lock_sock in sco_sock_connect before acquiring hdev->lock is retained.
These changes mirror similar fixes earlier in ISO sockets.
Fixes: 9a8ec9e8ebb5 ("Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm") Signed-off-by: Pauli Virtanen pav@iki.fi Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Alexander Ofitserov oficerovas@altlinux.org --- net/bluetooth/sco.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 0e1f5dde7bfec..99b149261949a 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -126,8 +126,11 @@ static struct sco_conn *sco_conn_add(struct hci_conn *hcon) struct hci_dev *hdev = hcon->hdev; struct sco_conn *conn = hcon->sco_data;
- if (conn) + if (conn) { + if (!conn->hcon) + conn->hcon = hcon; return conn; + }
conn = kzalloc(sizeof(struct sco_conn), GFP_KERNEL); if (!conn) @@ -268,21 +271,21 @@ static int sco_connect(struct sock *sk) goto unlock; }
- hci_dev_unlock(hdev); - hci_dev_put(hdev); - conn = sco_conn_add(hcon); if (!conn) { hci_conn_drop(hcon); - return -ENOMEM; + err = -ENOMEM; + goto unlock; }
- err = sco_chan_add(conn, sk, NULL); - if (err) - return err; - lock_sock(sk);
+ err = sco_chan_add(conn, sk, NULL); + if (err) { + release_sock(sk); + goto unlock; + } + /* Update source addr of the socket */ bacpy(&sco_pi(sk)->src, &hcon->src);
@@ -296,8 +299,6 @@ static int sco_connect(struct sock *sk)
release_sock(sk);
- return err; - unlock: hci_dev_unlock(hdev); hci_dev_put(hdev);