From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31708C43381 for ; Tue, 26 Mar 2019 06:36:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3B8F2075E for ; Tue, 26 Mar 2019 06:36:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553582206; bh=De+R0y8rKl4XjvIhDlCCz9wpJ3gqTC2/H1gEUvoZ018=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Q2kcS+O1ddCw6DXiquq+tO862cnw1EGN8ZJXNcolqd1yE+d3bArqCLmTCMER1MnXw wbgVv84+NZqEVxemFvGvzewXd7c/TMOSTio2OUNORAe93wR/y1Tek7opQcFtVhCHmF KIPa/N1mRdJ5E71dYH8MvYB3dw4P4wJsaRVv1lyA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732261AbfCZGgo (ORCPT ); Tue, 26 Mar 2019 02:36:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:49356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731428AbfCZGgl (ORCPT ); Tue, 26 Mar 2019 02:36:41 -0400 Received: from localhost (unknown [104.132.152.111]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 066262070B; Tue, 26 Mar 2019 06:36:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553582200; bh=De+R0y8rKl4XjvIhDlCCz9wpJ3gqTC2/H1gEUvoZ018=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a9pHa9bV1N+wiyZQ8DLbaZZIpsbCL7omPKSsRusNguf4w71QnRWo+sF0iVoHoZ7U4 f1ti0K4B+rbaWXfzNnqBh+Q/uu9tBdG4hP2PGGg85Or3LPpOl0tRZIL6jLBjRKBQhK uaHWLWgE/65SNpYR3SE1qr2p/vD6GsTLTEgmDChw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+fdc00003f4efff43bc5b@syzkaller.appspotmail.com, Myungho Jung , Marcel Holtmann Subject: [PATCH 4.19 31/45] Bluetooth: Fix decrementing reference count twice in releasing socket Date: Tue, 26 Mar 2019 15:30:14 +0900 Message-Id: <20190326042704.305533235@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190326042702.565683325@linuxfoundation.org> References: <20190326042702.565683325@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Myungho Jung commit e20a2e9c42c9e4002d9e338d74e7819e88d77162 upstream. When releasing socket, it is possible to enter hci_sock_release() and hci_sock_dev_event(HCI_DEV_UNREG) at the same time in different thread. The reference count of hdev should be decremented only once from one of them but if storing hdev to local variable in hci_sock_release() before detached from socket and setting to NULL in hci_sock_dev_event(), hci_dev_put(hdev) is unexpectedly called twice. This is resolved by referencing hdev from socket after bt_sock_unlink() in hci_sock_release(). Reported-by: syzbot+fdc00003f4efff43bc5b@syzkaller.appspotmail.com Signed-off-by: Myungho Jung Signed-off-by: Marcel Holtmann Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_sock.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -831,8 +831,6 @@ static int hci_sock_release(struct socke if (!sk) return 0; - hdev = hci_pi(sk)->hdev; - switch (hci_pi(sk)->channel) { case HCI_CHANNEL_MONITOR: atomic_dec(&monitor_promisc); @@ -854,6 +852,7 @@ static int hci_sock_release(struct socke bt_sock_unlink(&hci_sk_list, sk); + hdev = hci_pi(sk)->hdev; if (hdev) { if (hci_pi(sk)->channel == HCI_CHANNEL_USER) { /* When releasing a user channel exclusive access,