From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: [patch v3] ALSA: rawmidi: fix the get next midi device ioctl Date: Thu, 9 Sep 2010 00:11:41 +0200 Message-ID: <20100908221141.GD3463@bicker> References: <20100908085308.GC32047@bicker> <20100908193641.GA3463@bicker> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qy0-f179.google.com (mail-qy0-f179.google.com [209.85.216.179]) by alsa0.perex.cz (Postfix) with ESMTP id 31BB010388B for ; Thu, 9 Sep 2010 00:11:58 +0200 (CEST) Received: by qyk9 with SMTP id 9so656321qyk.17 for ; Wed, 08 Sep 2010 15:11:57 -0700 (PDT) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Jaroslav Kysela Cc: ALSA development , Takashi Iwai , Clemens Ladisch , kernel-janitors@vger.kernel.org, Kyle McMartin , Ulrich Drepper List-Id: alsa-devel@alsa-project.org If we pass in a device which is higher than SNDRV_RAWMIDI_DEVICES then the "next device" should be -1. This function just returns device + 1. But the main thing is that "device + 1" can lead to a (harmless) integer overflow and that annoys static analysis tools. Signed-off-by: Dan Carpenter --- V2: In the first version I made negative values return -EINVAL V3: We shouldn't return -EINVAL for numbers which are too large but just set the next device to -1. diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index eb68326..df67605 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -829,6 +829,8 @@ static int snd_rawmidi_control_ioctl(struct snd_card *card, if (get_user(device, (int __user *)argp)) return -EFAULT; + if (device > SNDRV_RAWMIDI_DEVICES) /* next device is -1 */ + device = SNDRV_RAWMIDI_DEVICES; mutex_lock(®ister_mutex); device = device < 0 ? 0 : device + 1; while (device < SNDRV_RAWMIDI_DEVICES) {