6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
[ Upstream commit dc26097bdb864a0d5955b9a25e43376ffc1af99b ]
This make use of kref to keep track of reference of iso_conn which
allows better tracking of its lifetime with usage of things like
kref_get_unless_zero in a similar way as used in l2cap_chan.
In addition to it remove call to iso_sock_set_timer on iso_sock_disconn
since at that point it is useless to set a timer as the sk will be freed
there is nothing to be done in iso_sock_timeout.
Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/bluetooth/iso.c | 88 ++++++++++++++++++++++++++++++++++++---------
1 file changed, 71 insertions(+), 17 deletions(-)
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 7a83e400ac77a..109bf58c982ae 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -35,6 +35,7 @@ struct iso_conn {
struct sk_buff *rx_skb;
__u32 rx_len;
__u16 tx_sn;
+ struct kref ref;
};
#define iso_conn_lock(c) spin_lock(&(c)->lock)
@@ -93,6 +94,49 @@ static struct sock *iso_get_sock(bdaddr_t *src, bdaddr_t *dst,
#define ISO_CONN_TIMEOUT (HZ * 40)
#define ISO_DISCONN_TIMEOUT (HZ * 2)
+static void iso_conn_free(struct kref *ref)
+{
+ struct iso_conn *conn = container_of(ref, struct iso_conn, ref);
+
+ BT_DBG("conn %p", conn);
+
+ if (conn->sk)
+ iso_pi(conn->sk)->conn = NULL;
+
+ if (conn->hcon) {
+ conn->hcon->iso_data = NULL;
+ hci_conn_drop(conn->hcon);
+ }
+
+ /* Ensure no more work items will run since hci_conn has been dropped */
+ disable_delayed_work_sync(&conn->timeout_work);
+
+ kfree(conn);
+}
+
+static void iso_conn_put(struct iso_conn *conn)
+{
+ if (!conn)
+ return;
+
+ BT_DBG("conn %p refcnt %d", conn, kref_read(&conn->ref));
+
+ kref_put(&conn->ref, iso_conn_free);
+}
+
+static struct iso_conn *iso_conn_hold_unless_zero(struct iso_conn *conn)
+{
+ if (!conn)
+ return NULL;
+
+ BT_DBG("conn %p refcnt %u", conn, kref_read(&conn->ref));
+
+ if (!kref_get_unless_zero(&conn->ref))
+ return NULL;
+
+ return conn;
+}
+
static struct sock *iso_sock_hold(struct iso_conn *conn)
{
if (!conn || !bt_sock_linked(&iso_sk_list, conn->sk))
@@ -109,9 +153,14 @@ static void iso_sock_timeout(struct work_struct *work)
timeout_work.work);
struct sock *sk;
+ conn = iso_conn_hold_unless_zero(conn);
+ if (!conn)
+ return;
+
iso_conn_lock(conn);
sk = iso_sock_hold(conn);
iso_conn_unlock(conn);
+ iso_conn_put(conn);
if (!sk)
return;
@@ -149,9 +198,14 @@ static struct iso_conn *iso_conn_add(struct hci_conn *hcon)
{
struct iso_conn *conn = hcon->iso_data;
+ conn = iso_conn_hold_unless_zero(conn);
if (conn) {
- if (!conn->hcon)
+ if (!conn->hcon) {
+ iso_conn_lock(conn);
conn->hcon = hcon;
+ iso_conn_unlock(conn);
+ }
+ iso_conn_put(conn);
return conn;
}
@@ -159,6 +213,7 @@ static struct iso_conn *iso_conn_add(struct hci_conn *hcon)
if (!conn)
return NULL;
+ kref_init(&conn->ref);
spin_lock_init(&conn->lock);
INIT_DELAYED_WORK(&conn->timeout_work, iso_sock_timeout);
@@ -178,17 +233,15 @@ static void iso_chan_del(struct sock *sk, int err)
struct sock *parent;
conn = iso_pi(sk)->conn;
+ iso_pi(sk)->conn = NULL;
BT_DBG("sk %p, conn %p, err %d", sk, conn, err);
if (conn) {
iso_conn_lock(conn);
conn->sk = NULL;
- iso_pi(sk)->conn = NULL;
iso_conn_unlock(conn);
-
- if (conn->hcon)
- hci_conn_drop(conn->hcon);
+ iso_conn_put(conn);
}
sk->sk_state = BT_CLOSED;
@@ -210,6 +263,7 @@ static void iso_conn_del(struct hci_conn *hcon, int err)
struct iso_conn *conn = hcon->iso_data;
struct sock *sk;
+ conn = iso_conn_hold_unless_zero(conn);
if (!conn)
return;
@@ -219,20 +273,18 @@ static void iso_conn_del(struct hci_conn *hcon, int err)
iso_conn_lock(conn);
sk = iso_sock_hold(conn);
iso_conn_unlock(conn);
+ iso_conn_put(conn);
- if (sk) {
- lock_sock(sk);
- iso_sock_clear_timer(sk);
- iso_chan_del(sk, err);
- release_sock(sk);
- sock_put(sk);
+ if (!sk) {
+ iso_conn_put(conn);
+ return;
}
- /* Ensure no more work items will run before freeing conn. */
- cancel_delayed_work_sync(&conn->timeout_work);
-
- hcon->iso_data = NULL;
- kfree(conn);
+ lock_sock(sk);
+ iso_sock_clear_timer(sk);
+ iso_chan_del(sk, err);
+ release_sock(sk);
+ sock_put(sk);
}
static int __iso_chan_add(struct iso_conn *conn, struct sock *sk,
@@ -652,6 +704,8 @@ static void iso_sock_destruct(struct sock *sk)
{
BT_DBG("sk %p", sk);
+ iso_conn_put(iso_pi(sk)->conn);
+
skb_queue_purge(&sk->sk_receive_queue);
skb_queue_purge(&sk->sk_write_queue);
}
@@ -711,6 +765,7 @@ static void iso_sock_disconn(struct sock *sk)
*/
if (bis_sk) {
hcon->state = BT_OPEN;
+ hcon->iso_data = NULL;
iso_pi(sk)->conn->hcon = NULL;
iso_sock_clear_timer(sk);
iso_chan_del(sk, bt_to_errno(hcon->abort_reason));
@@ -720,7 +775,6 @@ static void iso_sock_disconn(struct sock *sk)
}
sk->sk_state = BT_DISCONN;
- iso_sock_set_timer(sk, ISO_DISCONN_TIMEOUT);
iso_conn_lock(iso_pi(sk)->conn);
hci_conn_drop(iso_pi(sk)->conn->hcon);
iso_pi(sk)->conn->hcon = NULL;
--
2.43.0
