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=-12.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 1FED4C43381 for ; Fri, 29 Mar 2019 14:49:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3A0E2184D for ; Fri, 29 Mar 2019 14:49:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553870968; bh=C8z9OReIKZI31Cv+IezHtyAB92/jiYFZN8Cp6wqTf2Y=; h=Subject:To:From:Date:List-ID:From; b=SeBFnpzc8O/Yl7MHpG1DEmJljDyNoayrC5UHMzDi0dvanhWBwnddDXZq5dAJwIQZe lDB2WvAeX5K0EVidKiRXfkn6yN008bUZpXnEeQQqdUGZHSzmr6BANzE+epDU+aOmgk UyoDrzXtr/IVmQ2xKXVUC1btPdorzyEjkaEb/g6Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729415AbfC2Ot1 (ORCPT ); Fri, 29 Mar 2019 10:49:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:35642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728848AbfC2Ot1 (ORCPT ); Fri, 29 Mar 2019 10:49:27 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 DC1E92183F; Fri, 29 Mar 2019 14:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553870966; bh=C8z9OReIKZI31Cv+IezHtyAB92/jiYFZN8Cp6wqTf2Y=; h=Subject:To:From:Date:From; b=aAm5Ut/llQ8UDXt+fYn02ro8ZhxiBQ7o1m4YSRLIibZZTa87JYwvMzwsXokmjJb/u 6bGgSvEPWCNwmNEtWZeTIqsn1ATbh2BRN+j8d+LzIamoBc2N/noy8sSabroPOlT7cS bPiBIocDzZc8WjXut7vvAX/mOSS9bMi+j5eHjrSQ= Subject: patch "Revert "tty: pty: Fix race condition between release_one_tty and" added to tty-testing To: gregkh@linuxfoundation.org, keun-o.park@darkmatter.ae, lkp@intel.com, stable@vger.kernel.org From: Date: Fri, 29 Mar 2019 15:49:24 +0100 Message-ID: <155387096458127@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled Revert "tty: pty: Fix race condition between release_one_tty and to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the tty-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 0eae4686a128d87503863a261e84887750c8bc68 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 29 Mar 2019 15:47:40 +0100 Subject: Revert "tty: pty: Fix race condition between release_one_tty and pty_write" This reverts commit b9ca5f8560af244489b4a1bc1ae88b341f24bc95 as 0-day shows it has a circular locking dependency. Fixes: b9ca5f8560af ("tty: pty: Fix race condition between release_one_tty and pty_write") Reported-by: kernel test robot Cc: Sahara Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 7 ------- drivers/tty/tty_io.c | 3 --- 2 files changed, 10 deletions(-) diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index ef72031ab5b9..00099a8439d2 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -116,12 +116,6 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) if (tty->stopped) return 0; - mutex_lock(&tty_mutex); - if (to->magic != TTY_MAGIC) { - mutex_unlock(&tty_mutex); - return -EIO; - } - if (c > 0) { spin_lock_irqsave(&to->port->lock, flags); /* Stuff the data into the input queue of the other end */ @@ -131,7 +125,6 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) tty_flip_buffer_push(to->port); spin_unlock_irqrestore(&to->port->lock, flags); } - mutex_unlock(&tty_mutex); return c; } diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index c27777f3b8c4..5fa250157025 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1448,13 +1448,10 @@ static void release_one_tty(struct work_struct *work) struct tty_driver *driver = tty->driver; struct module *owner = driver->owner; - mutex_lock(&tty_mutex); if (tty->ops->cleanup) tty->ops->cleanup(tty); tty->magic = 0; - mutex_unlock(&tty_mutex); - tty_driver_kref_put(driver); module_put(owner); -- 2.21.0