Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752498AbdDIRF1 (ORCPT ); Sun, 9 Apr 2017 13:05:27 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:33392 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752230AbdDIRFT (ORCPT ); Sun, 9 Apr 2017 13:05:19 -0400 Date: Mon, 10 Apr 2017 00:59:03 +0800 From: Wang YanQing To: gregkh@linuxfoundation.org Cc: jslaby@suse.com, linux-kernel@vger.kernel.org, mikey@neuling.org, viro@ZenIV.linux.org.uk, johan@kernel.org, peter@hurleysoftware.com, alex.popov@linux.com, robh@kernel.org, mpatocka@redhat.com, dvyukov@google.com, benh@kernel.crashing.org Subject: [PATCH] tty:tty_ldisc: add tty_ldisc_lock|unlock to prevent concurrent update to ldisc in tty_ldisc_deinit Message-ID: <20170409165903.GA9643@udknight> Mail-Followup-To: Wang YanQing , gregkh@linuxfoundation.org, jslaby@suse.com, linux-kernel@vger.kernel.org, mikey@neuling.org, viro@ZenIV.linux.org.uk, johan@kernel.org, peter@hurleysoftware.com, alex.popov@linux.com, robh@kernel.org, mpatocka@redhat.com, dvyukov@google.com, benh@kernel.crashing.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 682 Lines: 24 This patch could fix the issue that free_tty_struct in tty_io calling tty_ldisc_deinit without holding tty->ldisc_sem. Signed-off-by: Wang YanQing --- drivers/tty/tty_ldisc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index b1f7fa5..674421b 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -771,7 +771,9 @@ void tty_ldisc_init(struct tty_struct *tty) */ void tty_ldisc_deinit(struct tty_struct *tty) { + tty_ldisc_lock(tty, MAX_SCHEDULE_TIMEOUT); if (tty->ldisc) tty_ldisc_put(tty->ldisc); tty->ldisc = NULL; + tty_ldisc_unlock(tty); } -- 1.8.5.6.2.g3d8a54e.dirty