From: Lin Ma <linma@zju.edu.cn> stable inclusion from linux-4.19.194 commit 2b9e9c2ed0f1910b5201c5d37b355b60201df415 CVE: CVE-2021-3573 -------------------------------- commit e305509e678b3a4af2b3cfd410f409f7cdaabb52 upstream. The hci_sock_dev_event() function will cleanup the hdev object for sockets even if this object may still be in used within the hci_sock_bound_ioctl() function, result in UAF vulnerability. This patch replace the BH context lock to serialize these affairs and prevent the race condition. Signed-off-by: Lin Ma <linma@zju.edu.cn> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- net/bluetooth/hci_sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index d4e2a166ae176..78788e52a0399 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -755,7 +755,7 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event) /* Detach sockets from device */ read_lock(&hci_sk_list.lock); sk_for_each(sk, &hci_sk_list.head) { - bh_lock_sock_nested(sk); + lock_sock(sk); if (hci_pi(sk)->hdev == hdev) { hci_pi(sk)->hdev = NULL; sk->sk_err = EPIPE; @@ -764,7 +764,7 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event) hci_dev_put(hdev); } - bh_unlock_sock(sk); + release_sock(sk); } read_unlock(&hci_sk_list.lock); } -- 2.25.1