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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 2F29AC43381 for ; Fri, 22 Mar 2019 11:27:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2D41218A2 for ; Fri, 22 Mar 2019 11:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553254054; bh=X9KzL7YdKdfQObDszGbOfGhRk0bZyXkAum+gD+J8Rg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hbVJeC2SP1TYHeqqDB+t2pEBIqyq3Qv1vffo5e822p86AEiPy2hgjT6GHC1NGk3M+ xyF+SDnP6mO9kkPv3kbvvjkWmheXMxzbLkgIsEFDZHCI5PbLttIaNYcDPYuaK4whnk hVcZQs26mprMu0u9jTB4oRCgSlzPvXPNGvbOP5WQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729557AbfCVL1c (ORCPT ); Fri, 22 Mar 2019 07:27:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:55206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729541AbfCVL12 (ORCPT ); Fri, 22 Mar 2019 07:27:28 -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 51A13218A2; Fri, 22 Mar 2019 11:27:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553254047; bh=X9KzL7YdKdfQObDszGbOfGhRk0bZyXkAum+gD+J8Rg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tVlEUbOt18J38ep22TiX+otQQhh0W5Tc4MD+JRqXrmpOZQRvq/mMWZqIJhDuBtKad 2kcyrA+GMWh25A25ZkARAvKpbxFKxxKGl4FAT453Zw4oHCNUXUlSGG3clNRyicwjfv gjPPVvn6uOd9BDdSuaUcYevHbi+q1TBqWYL+9nlk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia-Ju Bai , "David S. Miller" , Sasha Levin Subject: [PATCH 4.4 016/230] isdn: i4l: isdn_tty: Fix some concurrency double-free bugs Date: Fri, 22 Mar 2019 12:12:34 +0100 Message-Id: <20190322111237.873712294@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111236.796964179@linuxfoundation.org> References: <20190322111236.796964179@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 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 2ff33d6637393fe9348357285931811b76e1402f ] The functions isdn_tty_tiocmset() and isdn_tty_set_termios() may be concurrently executed. isdn_tty_tiocmset isdn_tty_modem_hup line 719: kfree(info->dtmf_state); line 721: kfree(info->silence_state); line 723: kfree(info->adpcms); line 725: kfree(info->adpcmr); isdn_tty_set_termios isdn_tty_modem_hup line 719: kfree(info->dtmf_state); line 721: kfree(info->silence_state); line 723: kfree(info->adpcms); line 725: kfree(info->adpcmr); Thus, some concurrency double-free bugs may occur. These possible bugs are found by a static tool written by myself and my manual code review. To fix these possible bugs, the mutex lock "modem_info_mutex" used in isdn_tty_tiocmset() is added in isdn_tty_set_termios(). Signed-off-by: Jia-Ju Bai Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/isdn/i4l/isdn_tty.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c index 2175225af7421..8291e9cc949ad 100644 --- a/drivers/isdn/i4l/isdn_tty.c +++ b/drivers/isdn/i4l/isdn_tty.c @@ -1459,15 +1459,19 @@ isdn_tty_set_termios(struct tty_struct *tty, struct ktermios *old_termios) { modem_info *info = (modem_info *) tty->driver_data; + mutex_lock(&modem_info_mutex); if (!old_termios) isdn_tty_change_speed(info); else { if (tty->termios.c_cflag == old_termios->c_cflag && tty->termios.c_ispeed == old_termios->c_ispeed && - tty->termios.c_ospeed == old_termios->c_ospeed) + tty->termios.c_ospeed == old_termios->c_ospeed) { + mutex_unlock(&modem_info_mutex); return; + } isdn_tty_change_speed(info); } + mutex_unlock(&modem_info_mutex); } /* -- 2.19.1