From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:51614 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728422AbeJQBHT (ORCPT ); Tue, 16 Oct 2018 21:07:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hermes Zhang , Marcel Holtmann , Sasha Levin Subject: [PATCH 4.18 084/135] Bluetooth: hci_ldisc: Free rw_semaphore on close Date: Tue, 16 Oct 2018 19:05:14 +0200 Message-Id: <20181016170521.052539741@linuxfoundation.org> In-Reply-To: <20181016170515.447235311@linuxfoundation.org> References: <20181016170515.447235311@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hermes Zhang [ Upstream commit e6a57d22f787e73635ce0d29eef0abb77928b3e9 ] The percpu_rw_semaphore is not currently freed, and this leads to a crash when the stale rcu callback is invoked. DEBUG_OBJECTS detects this. ODEBUG: free active (active state 1) object type: rcu_head hint: (null) ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2024 at debug_print_object+0xac/0xc8 PC is at debug_print_object+0xac/0xc8 LR is at debug_print_object+0xac/0xc8 Call trace: [] debug_print_object+0xac/0xc8 [] debug_check_no_obj_freed+0x1e8/0x228 [] kfree+0x1cc/0x250 [] hci_uart_tty_close+0x54/0x108 [] tty_ldisc_close.isra.1+0x40/0x58 [] tty_ldisc_kill+0x1c/0x40 [] tty_ldisc_release+0x94/0x170 [] tty_release_struct+0x1c/0x58 [] tty_release+0x3b0/0x490 [] __fput+0x88/0x1d0 [] ____fput+0xc/0x18 [] task_work_run+0x9c/0xc0 [] do_exit+0x24c/0x8a0 [] do_group_exit+0x38/0xa0 [] __wake_up_parent+0x0/0x28 [] el0_svc_naked+0x34/0x38 ---[ end trace bfe08cbd89098cdf ]--- Signed-off-by: Hermes Zhang Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/bluetooth/hci_ldisc.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -543,6 +543,8 @@ static void hci_uart_tty_close(struct tt } clear_bit(HCI_UART_PROTO_SET, &hu->flags); + percpu_free_rwsem(&hu->proto_lock); + kfree(hu); }