This is a note to let you know that I've just added the patch titled Bluetooth: hci_sock: purge socket queues in the destruct() callback to the 5.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bluetooth-hci_sock-purge-socket-queues-in-the-destru.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 44faae29a0b9a1ef40d4fe0f067bca75ad75db96 Author: Nguyen Dinh Phi <phind.uet@xxxxxxxxx> Date: Fri Oct 8 03:04:24 2021 +0800 Bluetooth: hci_sock: purge socket queues in the destruct() callback [ Upstream commit 709fca500067524381e28a5f481882930eebac88 ] The receive path may take the socket right before hci_sock_release(), but it may enqueue the packets to the socket queues after the call to skb_queue_purge(), therefore the socket can be destroyed without clear its queues completely. Moving these skb_queue_purge() to the hci_sock_destruct() will fix this issue, because nothing is referencing the socket at this point. Signed-off-by: Nguyen Dinh Phi <phind.uet@xxxxxxxxx> Reported-by: syzbot+4c4ffd1e1094dae61035@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index f2506e656f3e4..33b3c0ffc3399 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -889,10 +889,6 @@ static int hci_sock_release(struct socket *sock) } sock_orphan(sk); - - skb_queue_purge(&sk->sk_receive_queue); - skb_queue_purge(&sk->sk_write_queue); - release_sock(sk); sock_put(sk); return 0; @@ -2059,6 +2055,12 @@ static int hci_sock_getsockopt(struct socket *sock, int level, int optname, return err; } +static void hci_sock_destruct(struct sock *sk) +{ + skb_queue_purge(&sk->sk_receive_queue); + skb_queue_purge(&sk->sk_write_queue); +} + static const struct proto_ops hci_sock_ops = { .family = PF_BLUETOOTH, .owner = THIS_MODULE, @@ -2112,6 +2114,7 @@ static int hci_sock_create(struct net *net, struct socket *sock, int protocol, sock->state = SS_UNCONNECTED; sk->sk_state = BT_OPEN; + sk->sk_destruct = hci_sock_destruct; bt_sock_link(&hci_sk_list, sk); return 0;