Re: [PATCH] drivers/staging/iio/frequency/ad9832.c: fix division by zero in ad9832_calc_freqreg()

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 22 Oct 2024 17:25:21 +0300
Dan Carpenter <dan.carpenter@linaro.org> wrote:

> It would be better if the subject prefix were "staging: iio: ad9832:"
> 
> [PATCH] staging: iio: ad9832: fix division by zero in ad9832_calc_freqreg()
Keep the frequency as well, though less important in staging as we
have only a few drivers there.

I fixed up the patch title and applied this to the fixes-togreg branch of iio.git.

Thanks,

Jonathan

> 
> On Tue, Oct 22, 2024 at 01:43:54PM +0000, Zicheng Qu wrote:
> > In the ad9832_write_frequency() function, clk_get_rate() might return 0.
> > This can lead to a division by zero when calling ad9832_calc_freqreg().
> > The check if (fout > (clk_get_rate(st->mclk) / 2)) does not protect
> > against the case when fout is 0. The ad9832_write_frequency() function
> > is called from ad9832_write(), and fout is derived from a text buffer,
> > which can contain any value.
> > 
> > Link: https://lore.kernel.org/all/2024100904-CVE-2024-47663-9bdc@gregkh/
> > Fixes: ea707584bac1 ("Staging: IIO: DDS: AD9832 / AD9835 driver")
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Zicheng Qu <quzicheng@huawei.com>  
> 
> Otherwise it looks good.
> 
> Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
> 
> regards,
> dan carpenter
>