From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Date: Thu, 09 Sep 2010 06:57:26 +0000 Subject: Re: [patch v2] ALSA: rawmidi: fix the get next midi device ioctl Message-Id: List-Id: References: <20100908085308.GC32047@bicker> <20100908193641.GA3463@bicker> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jaroslav Kysela Cc: ALSA development , Dan Carpenter , Clemens Ladisch , kernel-janitors@vger.kernel.org, Kyle McMartin , Ulrich Drepper At Wed, 8 Sep 2010 23:29:14 +0200 (CEST), Jaroslav Kysela wrote: > > On Wed, 8 Sep 2010, Takashi Iwai wrote: > > > At Wed, 8 Sep 2010 21:36:41 +0200, > > Dan Carpenter wrote: > >> > >> If we pass in a device which is higher than SNDRV_RAWMIDI_DEVICES then > >> this function just returns device + 1 which isn't helpful. I've > >> modified it to return -EINVAL instead. > >> > >> Also Smatch complains because the "device + 1" could be an integer > >> overflow. It's harmless, but we may as well silence the warning. > >> > >> Signed-off-by: Dan Carpenter > >> --- > >> V2: In the first version I made negative values return -EINVAL > >> > >> diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c > >> index eb68326..1633bac 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) > >> + return -EINVAL; > > > > This should be "device >= SNDRV_RAWMIDI_DEVICES". > > Also note that this check changes a bit semantics. All other NEXT_DEVICE > ioctls returns -1 if the value is beyond the last device (meaning no more > devices were found). So the > > if (device = SNDRV_RAWMIDI_DEVICES) > device = -1; > > check should be > > if (device >= SNDRV_RAWMIDI_DEVICES) > device = -1; > > ... resulting in one line patch. But this doesn't work when you pass device = INT_MAX :) Takashi From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [patch v2] ALSA: rawmidi: fix the get next midi device ioctl Date: Thu, 09 Sep 2010 08:57:26 +0200 Message-ID: References: <20100908085308.GC32047@bicker> <20100908193641.GA3463@bicker> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.suse.de (cantor.suse.de [195.135.220.2]) by alsa0.perex.cz (Postfix) with ESMTP id 5E0E11038C0 for ; Thu, 9 Sep 2010 08:57:27 +0200 (CEST) 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 , Dan Carpenter , Clemens Ladisch , kernel-janitors@vger.kernel.org, Kyle McMartin , Ulrich Drepper List-Id: alsa-devel@alsa-project.org At Wed, 8 Sep 2010 23:29:14 +0200 (CEST), Jaroslav Kysela wrote: > > On Wed, 8 Sep 2010, Takashi Iwai wrote: > > > At Wed, 8 Sep 2010 21:36:41 +0200, > > Dan Carpenter wrote: > >> > >> If we pass in a device which is higher than SNDRV_RAWMIDI_DEVICES then > >> this function just returns device + 1 which isn't helpful. I've > >> modified it to return -EINVAL instead. > >> > >> Also Smatch complains because the "device + 1" could be an integer > >> overflow. It's harmless, but we may as well silence the warning. > >> > >> Signed-off-by: Dan Carpenter > >> --- > >> V2: In the first version I made negative values return -EINVAL > >> > >> diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c > >> index eb68326..1633bac 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) > >> + return -EINVAL; > > > > This should be "device >= SNDRV_RAWMIDI_DEVICES". > > Also note that this check changes a bit semantics. All other NEXT_DEVICE > ioctls returns -1 if the value is beyond the last device (meaning no more > devices were found). So the > > if (device == SNDRV_RAWMIDI_DEVICES) > device = -1; > > check should be > > if (device >= SNDRV_RAWMIDI_DEVICES) > device = -1; > > ... resulting in one line patch. But this doesn't work when you pass device = INT_MAX :) Takashi