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Subject: Re: [PATCH] ALSA: usb-audio: fix possible hang and overflow in parse_uac2_sample_rate_range()
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From: Xi Wang <xi.wang@gmail.com>
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Date: Sun, 8 Jan 2012 07:45:09 -0500
Cc: Jaroslav Kysela <perex@perex.cz>, Clemens Ladisch <clemens@ladisch.de>,
        Daniel Mack <zonque@gmail.com>, Wolfgang Breyha <wbreyha@gmx.net>,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
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To: Takashi Iwai <tiwai@suse.de>
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On Jan 8, 2012, at 4:09 AM, Takashi Iwai wrote:
> As of now, I have little time to evaluate, so I might have missed
> something, but I wonder whether 
> 
> 		/* avoid overflow */
> 		if (nr_rates == KMALLOC_MAX_SIZE / sizeof(int))
> 			break;
> 
> is the best way to check.  This looks ugly to me.
> If we need to limit the number of rates, better to define some proper
> numbers as the upper limit.  And then, it should warn, not only
> breaking loop.

Thanks for looking into this.  Yeah, I agree using something like
MAX_NR_RATES is better.  Is 65535 okay or do we need a larger limit?

- xi