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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 1C8E3C282D7 for ; Wed, 30 Jan 2019 09:50:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E37B62082C for ; Wed, 30 Jan 2019 09:50:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548841817; bh=sj0tNwJ0EzD0y9QvMKm6YFJlgw8lkwRLa0YbWW9X408=; h=From:To:Cc:Subject:Date:List-ID:From; b=XI391UD1peHU1ZfbdNVjdJo4agsJ9VzTqDDxyrk8w/97jPEmqpWKiYYQ63BRus2C5 DOxTE9x1uKSUm8wcdCoheHWnv/kEKeapOTWC0MBGsbg9nbAfGR6WGqgAyh2vH1WGfa CGH0CTFrKbw1DvUC4G1jzjwQqdPIOhqSpKfq2jiI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726713AbfA3JuQ (ORCPT ); Wed, 30 Jan 2019 04:50:16 -0500 Received: from mail-lf1-f65.google.com ([209.85.167.65]:46531 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726972AbfA3JuP (ORCPT ); Wed, 30 Jan 2019 04:50:15 -0500 Received: by mail-lf1-f65.google.com with SMTP id f5so16860183lfc.13; Wed, 30 Jan 2019 01:50:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=NanYgte5LFdggF1rtBl08xezcfm+tdZaDruR5cWG55Y=; b=YV3q/GSkZbYzq/BToC2dyD0Klg3M6VQiBKiohDw+U/nJ7lKMf6D++n06NUys9xI9MF PiScQNObINpjA+02ANz83fJ0gga5XywcI2FHBGbhVjkcRR/axDDdgAA+18UMcOP0sUOs Wh+ZGz6PiBUBcV+OZaJNYkXBXt9+bzaxCxa0g6Z4mMsnCOxfXgmRNkSnpM8tuYmho9Fd pc1ZfmgC+xi0Qc1G4nHgT+elfCO6hyTo5kY7I6hzHS+9MG2cRh2fiDmqfeHgvHr3sVxh xz82z9+O3YtKAjKkNCrQ8CtsrNIeAw/dhYpYGWdynNkOlvlwK9EZQR/Vvvg9xNnsci/7 tvFA== X-Gm-Message-State: AJcUukd/ikwnm35o/tgHv/vKddKAwL4iXGooHfY5UmYd1QHUo0oPRAjx /BIyCS4CjZ+MMc3OACOZizw= X-Google-Smtp-Source: ALg8bN7payxL1JrHkNoI1WZtp+OzSEGYEFsrKdAqIgOZFElInKcrwxGxp7b4cw6dBTGnPwnecS/P0w== X-Received: by 2002:a19:4345:: with SMTP id m5mr22821843lfj.142.1548841813454; Wed, 30 Jan 2019 01:50:13 -0800 (PST) Received: from xi.terra (c-74bee655.07-184-6d6c6d4.bbcust.telenor.se. [85.230.190.116]) by smtp.gmail.com with ESMTPSA id b25-v6sm188574lji.94.2019.01.30.01.50.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 Jan 2019 01:50:12 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.91) (envelope-from ) id 1gomVU-00017G-MP; Wed, 30 Jan 2019 10:50:08 +0100 From: Johan Hovold To: Greg Kroah-Hartman Cc: speakup@linux-speakup.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Johan Hovold , stable , Okash Khawaja , Samuel Thibault Subject: [PATCH] staging: speakup: fix tty-operation NULL derefs Date: Wed, 30 Jan 2019 10:49:34 +0100 Message-Id: <20190130094934.4231-1-johan@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The send_xchar() and tiocmset() tty operations are optional. Add the missing sanity checks to prevent user-space triggerable NULL-pointer dereferences. Fixes: 6b9ad1c742bf ("staging: speakup: add send_xchar, tiocmset and input functionality for tty") Cc: stable # 4.13 Cc: Okash Khawaja Cc: Samuel Thibault Signed-off-by: Johan Hovold --- drivers/staging/speakup/spk_ttyio.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/staging/speakup/spk_ttyio.c b/drivers/staging/speakup/spk_ttyio.c index c92bbd05516e..005de0024dd4 100644 --- a/drivers/staging/speakup/spk_ttyio.c +++ b/drivers/staging/speakup/spk_ttyio.c @@ -265,7 +265,8 @@ static void spk_ttyio_send_xchar(char ch) return; } - speakup_tty->ops->send_xchar(speakup_tty, ch); + if (speakup_tty->ops->send_xchar) + speakup_tty->ops->send_xchar(speakup_tty, ch); mutex_unlock(&speakup_tty_mutex); } @@ -277,7 +278,8 @@ static void spk_ttyio_tiocmset(unsigned int set, unsigned int clear) return; } - speakup_tty->ops->tiocmset(speakup_tty, set, clear); + if (speakup_tty->ops->tiocmset) + speakup_tty->ops->tiocmset(speakup_tty, set, clear); mutex_unlock(&speakup_tty_mutex); } -- 2.20.1